AEGIS

Water Treatment Controller

Technical Manual
 AEGIS Technical Manual
Contents
Safety

1. Overview
1.1 Applications
1.2 Sensor Inputs & Control Outputs
1.3 Communications
1.4 Field Upgrades
1.5 Data Logging

2. Installation-Commissioning
2.1 Cabling –Wiring
2.2 Water Meters –Flowswitches –Contact Sets

3. Control Configuration
3.1 Control Method
3.2 Special Controls Insight

4. Sensors
4.1 Compensation Insight
4.2 Calibration Defaults

5. Application Notes
5.1 Calculate ppm
5.2 Copy Volume
5.3 Feed-Verify & Inventory
5.4 Frequency Controlled Pumps
5.5 Password Security
5.6 Relay & Frequency Controls Comparison
5.7 System Alarms & Indicating LEDs
5.8 Units for Volumes & Temperatures
5.9 XML: URL Encoded Requests

6. Applications
6.1 Adjusting Inhibitor Feed with Varying Cycles

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 AEGIS Technical Manual

7. Sensor Driver Card Manuals

7.1 CT: Conductivity Temperature
7.2 B: Boiler Conductivity
7.3 OP: ORP-pH
7.4 CI: Dual 4-20mA Current Input
7.5 IO: 4-20mA Output
7.6 CR: Corrosion Rate
7.7 PT: pH-Temperature

Appendices

A: Revision Log

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 AEGIS Technical Manual
Safety Electrical Shock Hazard
Opening the controller enclosure with the controller plugged in, exposes the user
to AC line voltages on the backmost of the two controller circuit boards.

Ground the controller AC power to the ground screw labeled and located on the bottom, right of
the aluminum backplate.

External, 120VAC socket or optional plug boxes are provided with controllers installed in North
America. Both are grounded to the ground screw labeled located on the bottom, center of the
aluminum backplate.

USER WARNING : CAUTION

Water Treatment Controllers operate steam and water valves and may pump
hazardous, corrosive and toxic chemicals. Opening the controller enclosure
exposes user to the risk of electrical shock at power line voltages.

Understand fully the implications of the control setpoints, interlocks and alarms that
you select. Harm to personnel and damage to equipment may result from mis-
application.

Unplug or turn OFF the AC power to the controller if you have any concerns
regarding safety or incorrect controller operation and notify supervisory staff.

YOUR CONTROLLER
AEGIS Controllers are supplied in many different configurations, part numbers and
sensor sets. Applications extend beyond water treatment.

The HELP section available in the Aegis_User manual, depicts the installation
plumbing header showing the sensor set supplied with your controller. It also
includes the information for terminating the sensors supplied with your specific
controller part number.

The START-UP section available in the Aegis_User manual, is specific to your

application and details modifying the default controller settings for your site.

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 AEGIS Technical Manual

1. Overview

1.1 Applications
Aegis controllers are optimized for water treatment applications. These controllers measure the sensors used
to control water treatment chemical feed pumps, blowdown valves and bleed solenoids.

The control methods used to do both conventional and complex water treatment are built-in.
Sensor sets are easily modified post-purchase to meet changing site needs.
ON-OFF, AC powered pumps and solenoids may be mixed with frequency controlled pumps.

Aegis controllers do a lot more than the summary information in the following table:

Application Measures Controls

Cooling Towers Tower Conductivity Bleed on tower conductivity, on cycles of concentration, on
Make-up Conductivity ratio of make-upt obl eedv olume….
pH Feed Inhibitor on ppm setpoints, based on bleed,
ORP proportional to make-up,basef eed….
Corrosion Rate Feed pH correction acid ON/OFF, proportionately, by make-
Make-up Volume upv olume… Cont rol bothac i
d&caust i
c.
Gray water make-up Feed bleach on ORP using a pot feeder, or proportional.
Bleed Volume Base feed bleach and shock during biocide feed events.
Water Temperature Sum or difference water meters to feed inhibitor.
Flowswitch Prebleed and Lockout biocide feeds.
Tank level switches Block some chemical feed while others feed.
Chemical fed volume Feedoncor rosi
onr ate,temper atur e…. .
Calculate ppm based on volume fed & cycles of
concentration.
Boilers Boiler Conductivity for 1 to Captured sample & continuous blowdown controls.
3 boilers. Feed treatment based on each boiler make-up & meter
Condensate Conductivity amine based on the sum of make-ups or the steam demand.
Feed water volume for Feed sulfite on temperature or base feed.
each boiler Operate condensate bypass valves.
Steam demand Log, monitor and control on hardness analyzers.
Condensate pH Log and an alarm on condensate pH. Average pH to control
Day tank levels. time lagged condensate pH.
Verify feed Mix & blend day tanks.
Waste Water ORP, pH Hold & mix to hit target, conductivity, pH, ORP, temperature
Make-up and drain prior to drain.
volumes and rates. Feedf l
occul antsonv olume,t urbidity…
Tank high & low levels. Sequence feeds, mixing and discharge.
Conductivity Alarm on fail to feed.
Process Conductivity-Resistivity Feed or control based on ON/OFF setpoints, volume
Corrosion Rate measured, volume fed, time of day, day of week, base feed.
Up to 4 pHs or ORPs Alarm on runtime or volume fed or high or low sensor levels.
Rates as 4-20mA Delay on alarm to avoid transient states alarming.
Any mix of water meters Sequence on contact sets.
and contact sets not Invert the logical sense of contact sets.
exceeding 8 Ratio sensors and volumes.
Meter on volume fed.

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 AEGIS Technical Manual
1.2 Sensor Inputs & Control Outputs
Users can change the default names of sensors, pumps and valves to meaningful, site specific names.
For example, although you may name controllermet eri
nput‘P’to‘Ci tyMake-up’ ,‘P’i dentif
ieswher et
hemet
er
i
sconnect edandt helett
er‘P’i susedtor epresentt he‘Cit
yMake-up’i nputincont r olsanddat al oggi
ng.

Thecontroll
erusest hel etter s‘A’thr
u‘Z’ t
oi dentif
ysensor ,wat ermeter,flowswitch and contact set inputs and
the numbers 1 to 9 to identify AC power switching relays and frequency outputs.

‘
A’t
o‘G’and‘O’to‘
V’exi
stast
ermi
nalbl
ockswher
einput
sareconnect
ed.Sensori
nput
s‘H’to‘N’and
met
er/
cont
actseti
nput
s‘W’to‘
Z’ar
eusedtoimpl
ementmorecomplexcont
rolandmoni
tor
ingfunct
ions.

Any input may be used to control any output or outputs.

I/O Point Function Notes

Sensor A Fixed conductivity sensor Support for both cooling tower and boiler-condensate
drive sensors.
Most controllers have at least one conductivity sensor.
Sensor B Fixed thermal sensor Support for the 10mV/K and CTF type temperature sensors,
drive Ther mal compensat i
onf orthe‘ A’conduc tivi
tyorst and-alone
feedwater thermal sensor
Sensors Two sensor card slots. Plug & Play sensor cards auto-reconfigure the controller
C-D and E-F Each slot can take a when the card is installed.
single or dual sensor Available Card set: Conductivity-Temperature, Single & Dual
driver card Boiler Conductivity, Single & Dual pH-ORP, pH-
Temperature, Single & Dual Corrosion Rate, Dual 4-20mA
input. Single & Dual 4-20mA output.

Sensor G Fixed 4-20mA input Support for loop powered and isolated 4-20mA levels on
Chl or i
neorCl O2orf eedr ateort urbi
di
ty
…
Sensors H to N Phantom sensor inputs Inputs used to for calculated and manually entered values:
used for control and Calculated ppm & inventory-tank levels. Manually entered
logging. drop count-chemi cal t
estr esul t
s…
Meter-Contacts Eight digital inputs, Meter-volume inputs totalize, display volume today and this
O to V individually configurable year ,calculatet urbi ne‘ K’ factorsanddebouncec ont
act
as meter-volume or head meters.
contact set inputs Contact sets are flow and level switches. They are used to
interlock and to initiate feeds.
Meter-Contacts Phantom digital inputs A 4-20GPM i nputmaybeconv er
tedtoav ol
ume@ ‘ X’
W to Z used for control and Ar el aystatemaybe‘ mi rrored’byphantom input‘ Y’whi chis
logging. used to start a rinse sequence by controlling relay No.4
Relays 1 to 5 AC Line powered Controller powered outputs switch 120 or 230VAC pumps,
ON/OFF controls valves & solenoids ON/OFF. Log time ON.
Alarm on runtime per actuation & per day.
Relays 2-5 are SPDT for motorized valves requiring power
OPEN & power CLOSE.
Frequency DC isolated, Variable speed feeds, with presets for popular pump
Outputs 6 to 9 non-mechanical ml/stroke and maximum rate. Calculates & logs volume fed.
0 to 400Hz Use volume fed to calculate ppm & inventory.

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1.3 Communications
1.3.1 USB Services
All Aegis controllers include a USB port which is used for three purposes:
1. Upload of logged data in XML format to a notebook PC or a PDA operating as a USB host.
2. Download of View-Configuration Sets into the AEGIS.
3. Upload of the current controller configuration from the AEGIS to support generation of View-Configuration
Sets and for controller cloning.

1.3.2 Configuration-View sets:

Contr
oll
erswi
ththe‘
LB’Ether
netopt
ionareloadedwit
hfrom 1t
o15Vi ew-Configurations. One of these is
sel
ectedwhenthecont
rol
l
erismanuf
ac t
uredtobethe‘asshi
pped’v
iew-configuration.

Installed View-Configurations represent possible, future uses of the controller.

For example ORP and/or make-up conductivity sensors and controls are routinely added to installed
controllers. Configuration and Views are preloaded to support these upgrades.

1.3.3 LAN TCP-IP:

The LB controller option adds a 10 Base T, RJ45 Ethernet port with a user assigned static IP. The controller
operates as an HTML micro-ser verf orc ommand&cont r
olusingI E7andMozi l
la’
sFi refoxbr owser s.
Logged data is served as an XML file in response to an HTML request.

1.3.3 Modem:
The RM controller option adds a 57,600 baud micro modem that provides a PPP connection so that remote
users can browse the controller. AJAX supports the same graphical View interface used by on-site users.

1.4 Field Upgrades

Sensor driver cards can be added after installation by powering OFF the controller, plugging in the upgrade
card and powering ON. The controller recognizes the new hardware and auto-configures, modifying the LCD
display to add the new sensor inputs and sub-menus. The diagnostic browser view auto-enables the new
sensors and displays their current values.

No additional hardware is required to connect another water meter, flow or level switch. Enable the input and
the new device appears automatically in all of the selection and configuration menus.

1.5 Data Logging

Each enabled input and output is logged by the controller as a user set interval from 5 to 1440 minutes. Each
I/O can be independently logged at its own rate. The default rate for all I/O is 60 minutes with a 600 sample log
size. Sensors log minimum, maximum and average. Water meters log volume. Contact sets log time ON.
Power Relays controlling pumps and valves, log ON time in seconds.
Frequency controlled pumps log volume pumped in mL in each log period..

Alarms are time & date stamped. The last 25 controller activities are time and date stamped with the user ID.
Note: Data logging of relay ON time stops when AC fuse fails since without a fuse a relay
can’tpowerONapump,v al
veorsol enoid.

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2. Installation-Commissioning
2.1 Cabling –Wiring
2.1.1 Controller Wiring Terminals

Controllers consist of two circuit boards, a front Measure circuit board and a back Power board.
The front, Measure circuit board supports 7 sensor inputs & 8 digital Inputs.
I
tincludesa2l i
nex16c har acterLCDdi spl ay,USBTy pe‘ B’j ac kandami crocontr
oll
ermodul e.

Cable to
Optional
Modem
Power
Card
Measure Card
Sensors Sensors
‘
C’&‘ D’ Modem Power
‘
+’ ‘
A’‘
B’ ‘E’&‘F’
Expansion
Power IN RS485
18 VDC

LCD Display
Optional Optional
Sensor Sensor
Card Card
Socket Socket

Running

Control USB
Module ‘
B’Size
with Jack
Optional
Ethernet
Jack
Conductivity
Red Blk Wht Grn 4-20mA Meter & Contact Set Inputs
+DC Power
S1 S2 T G+ Output O P Q R S T U V
A&B

Sensors Sensor Turbine Contact Head

RJ45
‘A’&‘ B’ ‘
G’ & Current & Turbine Meters
Ethernet
Conductivity Jack Loop Flow & Level Switches
Temperature Power
Sensor

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 AEGIS Technical Manual

2.1.1 Controller Wiring Terminals cont.

The back, Power circuit board has 5 ON/OFF Power Relays, 4 Variable Frequency Feed outputs and
the controller power supply.
The Ai, industrial version of the Aegis, includes an enclosure door mounted AC Power ON/OFF switch.

Cable to
Measure Power Card
Card

To Measure Card

Line
Voltage
Select Relay
Fuse
5 Power Relay 4 Pump
AC Power ON/OFF
cabling to Frequency
115V Controls
optional AC DC Controls
door mounted FREQUENCY CONTROLS
AC RELAYS 1-3 AC RELAYS 4-5
ON/OFF RUN R1 R2 R3 R4 R5 P6 P7 P8 P9
AC POWER NO NC NO NC NO NC NO NC NO A B A B A B A B
L LM N N NEUTRALS

A&B A&B A&B A&B A&B

Variable
AC Power AC Power to
Frequency
IN & fused Solenoids,
Pump
Auxiliary Power Valves & Pumps
Controls
OUT

A blue tinted electrical shield, secured by two thumbscrews, covers the terminals of the Power board.
Controllers may be supplied prewired with either 120VAC NEMA sockets or with an optional plug box.
Variable frequency pump control cables may be pre-wired.

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2.1.2 Enclosure Entries

Enclosure: Cable-Conduit Entries

A = PG9, Pump No.1, 39/64" or 15.2mm

B = PG9, Pump No.2, 39/64" or 15.2mm
C = PG9, Pump No.3, 39/64" or 15.2mm
D = PG13.5, Ethernet, 18.6mm
E = PG9, CTF Sensor, 39/64" or 15.2mm
F = PG9, AC Power cord, 39/64" or 15.2mm
G = ½"NPT, Solenoid, 51/64" Bottom, front
Hinge side H = PG9, Pump No.4, 39/64" or 15.2mm surface
of enclosure I = PG11, Pumps 6-9, ¾" or 18.4mm of enclosure
J = PG11, Sensors, ¾" or 18.4mm

A B C D E

0.6" 0.6" 0.6" 0.8" 0.6"

0.6" 0.7" 0.75" 0.75"

½" Conduit

F G H I J

Warning 1:
Remove the controller frame assembly prior to drilling additional enclosure entries to prevent damage to
wiring and circuit boards. The frame assembly is secured by 4 Phillips corner screws.

Warning 2:
Do not put conduit entries in the top of the enclosure.
Resulting conduit condensation and failure to seal may damage controller circuit boards.
Paralleling sensors within the enclosure cabling with AC power will cause measurement errors.

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2.1.3 Wiring Rules

Analog Sensor Wiring

Analog sensors (pH, ORP, conductivity, corrosion rate, temperature, 4-20mA…),cont actset
s ,wat
ermeters
and flowswitches may be cabled in a common conduit without causing operational problems.

Do not mix AC Line, 120VAC & 240VAC wiring with any sensor or communications cable in a common
conduit. Grounded, metallic conduit is preferred in areas where variable frequency drives operate.

Sensor cables, with the exception of pH sensors, may be extended in paired AWG22, 0.25mm 2 cable.
Ensure that cabling splices are accessible in conduit fittings or junction boxes.

Verify that the shields on contact head water meters are also spliced when meter cables are extended.
Ground cable shields at one end only to the internal frame lower bottom grounding screw.

Etherenet LAN Cabling

CAT5 LAN cabling is limited to a maximum of 300ft / 100m from controller to access hub.
Do not exceed this limit.

AC Controller Power
Power the controller using a dedicated, separate breaker in the local lighting-distribution panel.
Do not route the controller AC power in common conduit with variable frequency pump drives.

AC Power to Valves & Solenoids

Controller ON/OFF relays switch and power the AC line to valves & solenoids. Ensure that each valve &
solenoid has a dedicated neutral cable between the controller and the valve or solenoid. Do not share a
common neutral to multiple valves or solenoids.

Fractional Horsepower Chemical Feed Pumps

The controller ON/OFF relays are fused at 5 amps total which will power multiple solenoid driven chemical
feed pumps and solenoid coils. Fractional horsepower chemical feed pumps cannot be directly powered by
the controller. Use the controller 120VAC control output to switch a motor start relay with a 120VAC coil.
Fractional horsepower feed pumps are commonly used in high pressure boiler chemical feed applications
and waste water polymer feeds.
Typically the motor inrush current requires a dedicated breaker and separate AC feed from the controller
AC power breaker.

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 AEGIS Technical Manual
2.2 Water Meters –Flowswitches –Contact Sets
Wat ermet er
s,f
lowswi t
chesand‘ dry’contactsetsar econnec t
edt oi nputter
minal
s‘O’
thr
ough‘
V’andagr
ound
terminal. 5VDC limited by 10K puts 1/2mA through a closed contact set.

Hall effect Turbines and Paddlewheel water meters are powered by the 15-22VDC controller supply, thermally
fused at 100mA.

Connecting Meters & Flowswitches

Upper, Measure Card

Conductivity
Red Blk Wht Grn 4-20mA Meter & Contact Set Inputs
+DC Power
S1 S2 T G+ Output O P Q R S T U V
A&B

Red
Red

Black
Red

White
Dry Contact Set
Flowswitches
Seametrics type & Interlocks
Turbine Water
Meters
Controllers are defaulted to
Black
input‘ O’asmake- upmet er
andinput‘ S’ast he Red
flowswitch, operating
interlock

Water Meters, Flowswitches and Contact

Sets may be connected any digital input 'O'
to 'V'
Contact Head
Water Meters

Connect cabling shields at the controller ends of the cable only, to any ground terminal either on the Measure
card or on the aluminum backplate, bottom, center

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 AEGIS Technical Manual
3. Control Configuration
3.1 Control Method

3.1.1 Relays 1 to 5
Sets the deadband response of an ON/OFF relays controlled by sensors A..N.
Not applicable to relays controlled by volume meters or contact sets O..Z.

Method Function Examples

Rising Setpoint ON: Sensor > Turn ON Setpoint Tower Bleed
OFF: Sensor < Turn OFF Setpoint Boiler Blowdown
Condensate Bypass
Acid Feed
Falling Setpoint ON: Sensor < Turn ON Setpoint Oxidant Feed
OFF: Sensor > Turn OFF Setpoint Caustic Feed
Between Setpoints ON: Sensor < Turn ON Setpoint Blocking Controls
& Sensor > Turn OFF Setpoint Level Controls
OFF: Sensor > Turn ON Setpoint
Sensor < Turn OFF Setpoint
Event Rising Rising Setpoint Acid wash –flush
Operates only during Timed Events Cleaning controls
Event Falling Falling Setpoint Oxidant slug feeds
Operates only during Timed Events
Event Between Between Setpoints Blocking –sequencing
Operates only during Timed Events controls

3.1.2 Frequency Controlled Pumps 6 to 9

Sets the variable frequency control range for pumps controlled by sensors A..N.
Not applicable to pumps controlled by volume meters or contact sets O..Z.

Method Function Examples

Always Frequency varies proportional to Proportional acid or oxidant
sensor value when value between controls.
setpoints Replaces 4-20mA controlled
ON & maximum SPM when Sensor pumps.
greater than Turn ON
OFF when Sensor less than TurnOFF
During Events Control active during events until Proportional oxidant feed
event volume pumped. during a feed event.

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3.2 Special Control Insight

3.2.1 Bleed & Feed Inhibitor Feeds

Bleed & Feed use is limited to sites where the bleed OR the inhibitor pump is undersized and there
not enough time between bleed periods to pump inhibitor.
Bleed then Feed is the preferred inhibitor feed method for sites, which do not have a make-up water
meter.
Sites which have wide variation in make-up conductivity typically will have problems maintaining the
target inhibitor level using Bleed & Feed.
Poor location of feed point and bleed take-off may result in inhibitor being pumped down the drain.
Bleed setpoint dead band should be set to 1% for short bleed and short feed periods.

3.2.2 Bleed then Feed Inhibitor Feeds

Bleed then Feed is the preferred inhibitor feed method for sites that do not have a make-up or bleed
water meter.
Do not use Bleed then Feed at sites where the bleed or inhibitor feed pump is undersized. There may
not be enough time between bleed periods to feed inhibitor.
Sites which have wide variation in make-up conductivity typically will have problems maintaining the
target inhibitor level using Bleed then Feed.
Bleed setpoint dead band should be set to 1% for short bleed then feed periods.

3.2.3 Percentage Time –Base Feed Inhibitor, Boiler Treatment, Oxidant Feeds
Commonly used method to feed boiler chemicals where a contact set closes when the boiler is on-
line.
Typically boiler chemistry is verified by the operator, adjusting % time or mL/minute feed rate as
required to hit the target ppm.
Reliable method of control for static systems or where users manually adjust feed rates in response
to on-site testing or process changes.
Particularly useful where a contact set or flowswitch opens when the system is offline. Percentage
Time or Base Feed Time controls do NOT accumulate time when the interlock is OFF.

3.2.4 Prebleed –Lockout Biocide Feeds

Usedwher ey oucan’ tgett hesitetos tar
tt here-circulation pump early on biocide feed days.
Since Prebleeding dumps both inhibitor and water, avoid it if possible.
It’
spr ef erabl
et ofeedbi ocidesintoat owert hat’
snotundert her
mall oadwher ey oucanget
the kill time at the target concentration without make-up diluting the biocide.

If you need to use this control, keep it as simple as possible. If you only need Prebleed but not
Lockout, then zero the Lockout time. Lockout times that extend into the high load period may cause
the tower to overcycle. On site staff may be concerned that the controller has not opened the bleed
even though the conductivity is greater than the Turn On setpoint.

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 AEGIS Technical Manual

3.2.5 Captured Sample Boiler Blowdown Controls: Relays 1-5

Start-up
Controllers with more than one boiler blowdown control should always be commissioned one boiler at
at i
me.I t
’seasyt oc ross -wire sensors, valves and/or interlocks and very difficult to diagnose since
plumbing problems are also common on start-up.
Disconnect the sensors, valves and interlocks for all boilers but one.
Ver ifyeachboi l
er ’
sv al veoper at
esandi tssensormeasur est heboi l
erwat erconduc tivi
tyandi t
’s
interlock stops blowdown. Then repeat for the next boiler.
Sensor Watch
This sub-menu option on the controlling conductivity sensor is the best tool to identify plumbing
problems and flashing. Read the AEGIS user manual section on Captured Sample and then view
Sensor Watch through a Sample-Measure-Blowdown sequence.
If you are seeing flashing at the sensor, you are likely to have control tracking problems as the sensor
tries to measure a varying mix of steam & water after the sampling valve closes. Extending the
MEASURE period to 120 seconds sometimes helps but corrective action to remove the cause of
flashing always improves control.
Plumbing
Make sure that the throttling valve is always downstream of the valve or solenoid and installed
correctly. If you install a throttling needl
ev alvebackwar ds,y ou’llbereplaci ngi t.
The optimum control occurs when any flashing occurs downstream of the throttling valve.
This is particularly important on boilers operating at less than 100psi steam since steam rated
solenoids are more sensitive to flashed deposits than motorized valves.

If this boiler previously had a continuous blowdown controller installed and did not have a throttling
valve, locate the orifice union and ensure that it is downstream of the sensor and blowdown valve.

Althoughi t’sconv enienttohav et hebl owdownv alv eaccessi blesoy oucanseet hest em posi
tion,it’
s
not necessary for the correct operation of the controller. You can install the sensor, blowdown valve
and throttling valve on horizontal or vertical runs of the surface blowdown line above or below the
boiler water line. Maintenance may be difficult, but blowdown function will not be compromised. The
l
ongert hepi pingr untothesensor ,themor ewat ery ou’llremov et ogetasampl e.

Missing, Corroded or Intermittently Immersed Surface Blowdown Lines

An internal surface blowdown line that extends below the boiler water level is an option on some
boilers.You’ l
lseet hisfaultoccasional lyonanewi nstall
ations tart
-up. Sensor Watch displays a low
value with not much variance, measuring only steam.

Ift
heboi lerwat erleveldr
opsbel owt hebot t
om oft hesur facebl owdownl ineasl oadv ari
esy ouwon’ t
able to control blowdown. If you are not flashing at low loads, the best way to see this problem is to
temporarily remove the Captured Sample special control & adjust setpoint to blowdown. If the Sensor
Wat chv alueis n’tstabl
e,thesur facebl owdownl inei snotal way simmer sed.

Corroded surface blowdown lines are rare but not unknown.

Get suspect piping inspected dur ingt henex toutagebutdon’
tuset
hisasacauseofcont
rolpr
obl
ems
unless you are able to eliminate all other causes.

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 AEGIS Technical Manual
3.2.6 Time Modulation: Relays 1-5
Application: Cycles a chemical feed pump ON/OFF, decreasing the ON time as the controlling
sensor approaches the Turn OFF setpoint
Typically used for pH control, reducing acid feed as the Turn OFF setpoint is
approached.
Usei fy oucan’ tuseav ariabl ef r
equencycont rol
ledpump.

Setup: User selects a relay & selects Time Modulation Special Control
User sets Time Period in seconds, minimum 60, maximum 600 seconds.

Operation: Relay ON time = [ (Control –Turn OFF Setpoint) / Deadband ] x Period

where Deadband = Turn ON –Turn OFF setpoints.
Relay ON 100% of Period when Control is greater than Turn ON setpoint
Relay is OFF when Control is less than Turn OFF setpoint.

Example: Acid Pumps Turn ON = 10pH and Turn OFF = 8pH. Period = 120 seconds
At pH >= 10, Pump ON for 120 seconds in every 120 seconds
At pH = 9.5, Pump ON for 90 seconds in every 120 seconds
At pH = 9.0, Pump ON for 60 seconds in every 60 seconds
At pH = 8.5, Pump ON for 30 seconds in every 120 seconds
At pH <= 8.0, Pump OFF

Notes: Time Modulation control is not applicable when the system response time is faster than
5x the Period. In the previous Example; If the measured pH moves from 10 to 8 in less
than 300 seconds, Time Modulation may not improve control.
Process buffering, pump setting, feed point and system volume all affect the response
to chemical feed.
Time modulation also works on Falling Setpoints.

3.2.7P Timed Cycling: Pumps 6 to 9

Application: Large volume systems where the response to a chemical feed or control action
is slow or delayed in time and continuous, proportional feed over or undershoots.
Swimming pool pH, conductivity and ORP controls are typical applications.

Setup: User selects a pump & selects Timed Cycling Special Control
User sets Period in minutes, minimum 1, maximum 360 minutes.
User sets Feed Volume in mL, minimum 1, maximum 10000 (10L, 3.785G)
Operation: Pumps setpoint volume @ MAX SPM.
Time Modulation turns OFF the pump after Feed mL.
Note: If the time to feed the user set volume is greater than the Period, the pump turns
OFF for 10 seconds & then starts the next feed cycle.
This overfeed is an error in setting either the feed volume (too high) or the period (too
short)
TimeModul at i
onkeepst hepumpOFFf or‘ Period’mi nuteswher e‘ Per i
od’
is reduced by the pump feed time.
During the OFF period, the system has time to respond to the ON Time feed.
Example: Time Cycling Feed = 250mL , Period = 60 minutes
It takes 14 minutes for a 18mL/minute pump to feed 250mL so the pump is ON for 14
minutes and OFF for 46 minutes.
If the controlling sensor measures below the TurnOFF setpoint during the feed period,
the pump turns OFF.
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3.2.7R Timed Cycling –Relays 1 to 5

Application: Large volume systems where the response to a chemical feed or control action
is delayed in time.
Swimming pool pH, conductivity and ORP controls are typical applications.

Setup: User selects a relay & selects Time Modulation Special Control
User sets ON Time in minutes, minimum 1, maximum 360 minutes.
User sets Period in minutes, minimum 1, maximum 360 minutes.
Controller forces Period >= ON Time.
Operation: Setpoint Controls turn ON the relay.
Time Modulation turns OFF the relay after ON Time minutes.
TimeModul ationkeepst her el
ayOFFf or‘ Period–ONTi me’ mi nut
es.
During the OFF period, the system has time to respond to the ON Time feed.
Example: Time Modulation ON Time = 10 minutes, Period = 60 minutes
Brine feed is controlled on conductivity using a Falling Setpoint.
Conductivity setpoint control turns ON the Pool Brine feed relay.
After 10 minutes the Pool Brine feed turns OFF.
After another 50 minutes the Pool Brine feed turns ON for another 10 minutes if below
the Turn ON setpoint or remains OFF if the conductivity is above the Turn OFF
setpoint.
Notes: Condensate systems are also slow to respond to amine feed.
However the response time may vary with time of year and steam production.

3.2.8 Holding Time

Application: Holding Time averages the value of a controlling sensor over a user-defined period.
Averaging lowers the effect of process transients and limits the effect of the delay
between feed and measuring the effect of the feed. Control of amine feed by a pH
sensor in the condensate return is a typical use of Holding Time control.

Notes: The number of samples used for control is the Period / Log Rate.
Log entries are an average over the Log Period.
You may choose to reduce the Log Period to increase response to transients or
increase the Log Period to limit transient response.
The same effect may be achieved by altering the Holding Time Period.

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 AEGIS Technical Manual
3.2.9 Varying Cycles
Application: Cooling towers where the make-up conductivity varies widely and is
measured by a separate conductivity sensor. The bleed (cycles of concentration) is
controlled by the ratio of the tower-to-make up conductivity within three user set
ranges. As the make-up conductivity changes, the cycles of concentration changes.
Typically, at lower make-up conductivities, higher cycles of concentration are possible.

This special control solves operational problems, but requires care when setting cycles
or concentration setpoints and maximum cooling tower conductivity.
I
fy oursitehasseasonal changes ,it’
spr eferabl
et os implymodi fythebleedsetpoints.

Warning: When the make-up conductivity falls, the bleed setpoint increases but
the bulk of the water in the cooling tower has not changed.
Example: If make-up conductivity changes from 500uS to 100uS, the cycles of
concentration setpoint may change from 2 cycles to 4 cycles. However @ 4 cycles, the
bulk of the water in the tower may be scaling.
Short Holding Time: If the holding time ( time required to exchange the tower water )
is short, then the 100uS make-up will quickly dilute the tower water to below scaling.
Non-Scaling: You may not be hardness cycles limited, so even @ 4 cycles, you may
not be in a scaling condition.

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 AEGIS Technical Manual

4. Sensors

4.1 Compensation
4.1.1 Analog Sensors A..N

Type Setup Notes

Thermal User selected thermal sensor Applied to conductivity sensors.
(Conductivity) A..N. Zer oat70For20C,dependenton‘ met r
icuni ts’
User set %/degree switch setting.
compensation. The defaults are 0.97%/F or 1.746%/C
Thermal User selected thermal sensor Applied to pH sensors.
(pH) A..N. Zero compensation at 7 pH.
Compensation adjusts sensor gain (slope)
+0.00467%/C above 25C & -0.0058%/C below 25C
pH thermal compensation can only be applied to
directly connected pH sensors and not to
4-20mA inputs which may represent pH.
Rate-to-Volume User selected water meter Typically a 4-20mA input proportional to gpm
O..Z displays and logs makeup rate or LBh steam production is converted to
resulting volume. volume to feed ON/OFF based on volume & time
User selected rate/minute setpoints.
or rate/hour Frequency controlled pumps can be controlled
directly by the 4-20mA level.
Corrosion Rate User set alloy number, default Controller sets alloy to default and conductivity
1.00, Carbon Steel sensort o‘none’onCRdr iveri nstal
lat
ion.
User selected conductivity Conductivity sensor optional.
sensor A..N, corrects corrosion Remove driver to remove compensation.
rate for conductivity.
Manual Entry Logs the results of ppm testing or any analog value.
Any analog input without a driver card, may be used
forManualEnt ryandphant om i nputs‘H’to‘ N’ .
Remov ebyset ti
ngcompensat i
ont o‘none’
Calculated Feed Verification calculated Remov ebyset ti
ngt o‘none’i nFeedVer i
fycont r
ol.
ppm log.
Inventory Feed Verification calculated Remov ebyset ti
ngt o‘none’i nFeedVer i
fycont r
ol.
tank volume log. Pumped volume may also be copied to an Inventory
input, reducing the tank volume by the volume
pumped.

Note: pH thermal compensation is seldom used in cooling towers since the pH is typically
between 7 & 8 so the effect or thermal compensation is minimal.

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 AEGIS Technical Manual

4.1.2 Water Meter Sensors O..Z

Switching from Contact Set to Water Meter clears the log on the switched input.

Type Setup Notes

Contact Head User set volume/contact Contact Head compensation turns ON software
debouncing.
Volume counts on contact closure.
Contact opening ignored.

Turbine or Userset‘
K’f
act
or,pul
ses/
uni
t Counts pulse on falling edge, 400Hz max.
Paddlewheel volume Ignores rising edge.

4.1.3 Contact Sets, Flowswitches, Fail-to-Sample Sensors O..Z

Switching from Water Meter to Contact Set clears log.

Type Setup Notes

Contact Set User selects Contact Set Contact sets are ON when closed and OFF when
open.
ON time is logged.
Contact sets used for interlocking, prevent relays
from turning ON when contact set is OFF, or open.

Contacts et smaybeconf i
guredas‘ i
nv er
ted’t
oac
t
and disply as ON when they are OFF.

Cont acts etsmaybeconf i

guredt o‘mi rror’a
controlled relay of frequency controlled pump, acting
&displ ayingas‘ ON’whent her elayorpumpi s‘ON’

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 AEGIS Technical Manual
4.2 Calibration
4.2.1 Single Point Calibration

All inputs A..Z with the exception of 4-20mA,ty

pe‘
CI’i
nput
s,ar
esi
ngl
epoi
ntcal
i
brat
ions
.
Calibration of contact set inputs is blocked.

SENSORS A..N:
Conductivity, Calculated: Sensor GAIN is adjusted so that the sensor value matches the
user
’scali
brationv alue.

Temperature, pH, ORP Sensor OFFSET is adjusted so the sensor value

& Corrosion Rate matchest heuser’
scal ibrat
ionv al
ue.

Inventory, Manual: Sensor OFFSET i ssets othesensorv al

uemat chest heuser ’s
calibration value. Since the GAIN on these inputs is zero, the
OFFSET is the input value for control and logging.

During calibration, users have the option to Reset to Factory, which resets the sensor GAIN & OFFSET to
default values (Refer to section 4.2.3).

If the calibration OFFSET or GAIN is outside fault limits, users are offered the option to OVERRIDE.
OFFSET or GAIN outside of the fault limits typically indicates a sensor, cabling or driver fault.

Users have the option to manually enter OFFSET and GAIN by selecting Sensor then Configure

The value of a sensor = Measured Level (mV) x GAIN + OFFSET.

This value may be modified by sensor compensation.

Compensation (Temperature, Rate-Vol ume,Corr
osi onRat
e…)i
sappl
i
edaf
terGAIN & OFFSET.

WATER METERS O..Z:

The user calibration value is Volume/contact for contact head meters
and‘K’ f
ac t
or( Pulsesperuni tvolume)fortur bineandpaddl ewheelmeter
s.

4.2.2 Two Point Calibration

Twopoi ntcalibrati
oni sli
mit
edt
osensort
ype‘ ,t
CI’ hedual4-20mA input driver.
Therear enof aultlimit
sonGAINorOFFSETfor‘
CI’drivers.
Refer to Section 7.4.

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 AEGIS Technical Manual
4.2.3 Reset to Factory

New sensor driver cards & reconfigured water meters are Reset to Factory on Power on.
User selected Reset to Factory loads the GAIN, OFFSET set from the following table.

Sensor Type Driver Factory Factory Fault Fault

Type Gain Offset MAX MIN

Boiler –Condensate B GAIN GAIN

Conductivity
Type = Boiler 2.0 -15 10 0.5
Type = Condensate 8.0 -90 12 3.0

Calculated Value 100 0 None none

Conductivity CT GAIN GAIN
Range >100uS 5.6 -35 10 2.5
Range <100uS 0.4 -10 0.55 0.25

Conductivity CTF CTF GAIN GAIN

(includes flowswitch) Cond. 10.6 -13.6 14.85 6.36
OFFSET OFFSET
Temp. -0.0905 234.7 255 215

Corrosion Rate CR 1 0 None None

4-20mA Current Input CI 1 0 None None

Manual Entry 1 0 0 0
ORP - pH OP OFFSET OFFSET
Type = pH 0.017 7 8 6
Type = ORP -1 0 50 -50

Temperature CT OFFSET OFFSET

US units 0.18 -459.4 -430 -590
Metric units 0.1 -273 -253 -293

Water meter
Contact Head 100 None None
Turbine 100

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 AEGIS Technical Manual

5. Application Notes
5.1 Calculate ppm
5.1.1 Calculation Method

The controller can automatically calculate inhibitor ppm by measuring three values:
1. The volume of inhibitor pumped into the tower.
2. The volume of make-up water.
3. The cycles of concentration

Andt
her
e’smor
ethanonewayt
omeas
ureorsett
he3v
alues:

1. Inhibitor Volume
The volume of inhibitor can be measured by a meter installed in the output of the inhibitor pump
(see Sidebar) or calculated by the number of strokes of a frequency controlled pump.

2. Tower Make-up
Tower make-up volume may be measured by the potable water make-up meter.
The tower may also have grey water make-up from an RO or wastewater recovery stream measured by a
separate meter.
Depending on the inhibitor feed method, you may elect to sum the gray water volume to the make-up meter
OR sum the Make-up & gray meters, to a third, phantom meter.
(Refer to 5.2 Copy_Volume)

3. Cycles of Concentration
The most accurate way to measure the Cycles value is to install a water meter on the bleed line,
The ratio of the make-up volume to the bleed volume is the cycles of concentration.

If the tower make-up conductivity is constant, you can also use a fixed cycles of concentration since as long as
you are in conductivity control, the cycles of concentration is fixed by the bleed setpoint.

Sidebar:
Accurate, positive displacement, 1mL/pulse Tacmina type meters may also be installed on the suction side of
higher pressure, fraction HP pumps used for boiler feed.

Lower cost, stroke counters on the pump output may be accurate enough for inhibitor ppm calculations and
work very well for fail-to-feed alarms.

The calculated volume fed by frequency-controlled pumps may be accurate enough for calculating ppm without
calibration. Higher accuracy requires pumping from a graduated cylinder and calibrating the mL/stroke.

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 AEGIS Technical Manual
5.1.1 Calculation Method cont.

Calculating Inhibitor ppm

Since the inhibitor feed system includes a make-up water meter, you will be controlling inhibitor based on tower
load by volume-time (ON-OFF Pump) or volume-ppm (Frequency controlled Pump) setpoints.

The ppm of inhibitor in the tower water = 1000000 x Cycles x Inhibitor Volume / Make-up Volume

Example: If the tower has made-up 25, 000gal l

onst oday&y ou’ vef ed3500mL
of inhibitor & you are running 2.5 cycles of concentration.

Inhibitor ppm = 92.5 = 1,000,000 x ( 2.5 x 3500mL ) / (3785mL/G x 25000G )

5.2.2 Configuration

Inhi bitorFeedMet er:’Chemi calVol ume’

Enable an unusedphy sicalmet erinputinthe‘ O’to‘ V’r angeandconnectt he1mL/ pul
sefeedmet erors t
roke
counter to the enabled input.
If you are feeding Inhibitor using a frequency controlled pump, you can use the pumped volume calculated
from the pump strokes x the mL/stroke in place of an actual feed meter.

In rare cases, you may be feeding inhibitor from more than one source, perhaps a frequency controlled pump
anda1mL/ s
trokef eedmet er.Ifthisist hecase,uset he‘ CopyVol umet o’confi
gur ationtocopy both inhibitor
volumest oaphant om volumei nputi nt he‘ W’ to‘
Z’range.
Thenuset hephant om vol
umeast he‘ Chemi calVol
ume’

The controller assumes inhibitor feed meter measures in mL, ignoring the user set units.

If you are using a pulse counter, cal

ibr
atethe‘ Chemi calVol ume’ met erinmL.
For example, if you are feeding at 0.1mL pulse, configure the pulse counter as a Turbine Meter
wi tha‘ K’Fac tor=10.

Tower Make-upMet er:‘Make-upVol ume’

The ppm calculation converts make-up volume to mL based on the current System Units setting:
US units converts measured make-up volume x 3785 mL/Gallon.
Metric converts measured make-up volume x 1000 mL/L.

Ty pical
lymet erinput‘O’ i
susedast hecoolingtowerorpr
ocessmake-up meter.
If more than one meter is used for make-up,usethe‘CopyVolumet
o’configurationt
ocopyt
hemake-up
v olumet oaphant om v ol umemet erinthe‘ W’to‘Z’r
ange.

I
nhibitorppm I nput :‘Calculateppm’
Enableanunused,phant om inputi
nt he‘ H’t o‘N’range.
Use a phantom input because ppm is calculated and not a physical, wired sensor.

Af
teryousel
ect‘
Cal
culat
eppm’ ,y
ou’
l
lneedt
osel
ectt
he‘
Chemi
calVol
ume’and‘
Make-upVol
ume’
met
er
l
ocati
onsi
nthe‘O’t
o‘Z’range.

I
fableedmeteri
savai
l
abl
e,set‘Cy
clesmet
hod’t
o‘Met
erCycl
es’,ot
herwisesel
ect‘
Fix
edCy
cles’andset
‘
Cycl
es’tot
herat
iooft
heCooli
ngTower/Feedwat
erMakeupconduct
iv
iti
es.

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 AEGIS Technical Manual
5.2.3 Operation

Calculating inhibitor ppm starts at midnight.

Until make-up volume and chemical fed volume are measured, the displayed and logged ppm value will be
zero. If you have set the ppm low alarm with a short delay on alarm, you will get nuisance alarms.

It’
snecessar ytor esetppm calculat
ionatmidnighttoav oidc umul ati
v eerrorsduet ot
heaccur acyl
i
mit
sof
inhibitor feed and water volume measurement and operational error sources like tower windage.

5.2 Copy Volume

5.2.1 Copying WaterMeter & Pump Volumes

Anincr easeinv ol
umeononewat ermet er‘O’ to‘ Z’canbeaddedt oanot herwat
ermet
er,al
l
owi
ngthe sum of
one or more water meters to display, control and log on another water meter.

Anincr
easeinpumpedvol
umeononeormor
eoft
hef
requencycont
rol
l
edpumps‘
6’t
o‘9’c
anbeaddedt
o
anywatermeter‘
O’t
o‘ .
Z’

The targeted water meter may be anact ual,phy sicalmet er‘O’ to‘ V’oraphant om met er‘
W’t
o‘ .
Z’
In either case, the target meter can be used for control, alarming, logging and reporting.

Theincreasei
nvol
umemeasuredbyanywatermeteri
nput‘O’thr
ough‘
V’orcal
cul
atedf
oranyf
requency
cont
rol
ledpump‘6’t
hrough‘
9’i
simmedi
atel
yaddedtothetargetwat
ermet
er

Sites with multiple make-up meters can sum to a common or phantom water meter & be used to control a
single inhibitor pump.
The volume from multiple frequency-controlled pumps fed from a common tank can be used to calculate tank
inventory.
Note: Pumpedv ol
umescopi edtowat ermet ers‘O’to‘Z’ar esummed.
Pumpedv ol
umescopi edtophant om inventoryi
nput s‘ H’t
o‘ N’ar
esubt r
ac t
ed.

‘
CopyVolume’allows you to use the sequential volume O:P type controls with more than one meter summed
t
o‘O’and/
or‘
P’
‘
CopyVolume’allows you to sum all of the water meters connected to the controller to one totalizing meter.

5.2.2 Typical Applications

Cooling Tower with Potable & Grey Water Make-up Meters

We’reusingwat ermet eri
nput‘ O’,named‘Tower Makeup’t omeasur et
hepot
abl
ewat
ermake-up and water
meterinput‘
Q’,named‘ Reclaim Makeup’to measure the grey water.

We’
veenabledinput‘
R’,conf
igur
editasawater meter & named it, ‘
Tot
alMake-up’
We’
veconf
iguredbothwatermeters‘
O’and‘Q’to‘CopyVol umet o’wat
ermeter‘
R’

Thevari
ablefr
equencypumpat‘
8’,named‘
Inhi
bit
orPump’has been configured to control using water meter
‘
R’witha120ppm setpoint.
Watermeters‘
O’and‘Q’measur
emake-up,i
ncr
easingt
hev
olumeofmet er‘ R’andf eedingi nhibit
oronpump
‘
8’t
omai nt
ain120ppm

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 AEGIS Technical Manual
5.2.2 Typical Applications cont.

Two Frequency Controlled Inhibitor Pumps, One Inhibitor Tank Level

We’ veenabledphant om input‘,i
J’ ncreaseditsr
esolutionto3di gi
tsaf t
ert hedeci mal
& renamed it Inhibitor Tank.
We’ veconf
igur edfrequencycont roll
edi nhi
bi
torpumps‘ 6’and‘8’ t
ocopypumpedv olumet o‘J’whi
ch
automati
callyset s‘J’compensat iont oInventory and puts 100 gallons (or liters) into the tank.

We’ v eput40gal l
onsofI nhi
bit
orintot he55Gal
lontankandusi ngthekey pad,we’v
ecal
i
brat
edInhibitor Tank
J to read 40.000 gallons.
We’ v esettheInhibitor Tank J Low Alarm = 10 Gallons & the High Alarm = 60
with the Delay on Alarm = 0 minutes.

Asi nhibi
torispumpedf rom eit
herpump‘ 6’or‘ ,t
9’ hedi splayedtankv olumeont heLCDdi spl
ayandt he
browser view falls.
At below 10 Gallons, an alarm shows on the LCD and the browser icon switches to the RED Alarm state.

5.3.3 Operation
Met
erst
arget
edby‘
CopyVol
ume’cannotbedi
sabl
edORchangedt
oac
ont
actt
ypei
nput
.

A water meter or frequency controlled pump cannot be copied more than once.
Soy oucannotcopymet er‘Q’ tobot hmet ers‘X’ &‘ Y’.Howev er two meters can be copied to a third meter and
a fourth meter can be copied to a fifth meter up to the maximum of 12 meter inputs in any one controller

Inthel i
mi t
,11met ers,‘O’to‘Y’canbecopi edt ometer12,‘
Z’.
Notet hat3ofthe11met ers,‘
W’ to‘ Y’ar ephant om met
ersr
epresent
ingei
t
herr
ate-to-volume conversions
and/or volumes of frequency-controlled pumps.

NOTE:
I
fthe‘ opt
Copy Volume to’ i
ondoesnotappear,thent
hismeteri
sthet
argetof‘
CopyVol
ume’andt
her
efor
e
cannotnotbe‘Copi
ed’toanyot
hermeter,bl
ockinganinfi
ni
tecount
.

Diagnostic:
Selecting Sensor/Diagnostic forawat ermet erthati
sthe‘
CopyVol
ume’t
argetf
oranot
herwat
ermet
eror
pump volume will display Status: Target Meter

Constraints:
1. Any water meter used t osum v olumesf rom othermeter scannotbesett o‘CopyVol ume’t opr event
ani nadver tenti
nfi
nitecountwheny ousum t oamet erwhi ch‘Copies’totheor i
ginat
ingmet er .
2. Youcannotdi sabl
eawat ermet erwi th‘CopyVol ume’setormakei tintoacont acti
nput until you set
the‘ Copy ’compensat i
ont o‘none’
3. Youcannotdi sabl
et het argetmet erofamet ers ett
o‘ CopyVol ume’unt i
lal
loft hemeterstar geti
ng
thesummi ngmet erar eeithertargetedonot hermetersORhav et he‘CopyVol ume’sett o‘none’
4. Rate-to-Volume compensation volume incremental values are copied between water meters.
5. All meters must use the same units to sum volumes or the sum has no meaning.

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 AEGIS Technical Manual
5.3 Feed Verify & Inventory
5.3.1 Methods

Any water meter input may used to verify flow while a pump, solenoid or valve is ON.
Oncetheusersetat i
mel i
mi tforani nc reasei nvolumeex pires,a‘Fai l
-to-Feed’ alar
m occur
s.

Anywat ermet er’smeas ur

edv
olumecanbedi
rect
edt
oanyanal
ogsensori
nput‘
H’t
hrough‘
N’andusedt
o
calculate tank inventory.

Volume Meters: Verify Feed

Chemical Pumps may have a precise 1mL/pulse positive displacement Tacmina type sensor on the pump
output tubing OR a switch on the pump outlet that provides a contact closure every time the pump strokes.
Water Meters: Verify Bleed, Blowdown, Drawdown, Make-up
Contact head or turbine type water meters may be installed on make-up, bleed, drain or dilution piping to verify
that the valve or solenoid has operated or opened and flow is not blocked or valved off.

Tank Inventory
Thev olumemeasur edbyanywatermeteri
nput‘
O’thr
ough‘
V’orcal
cul
atedf
oranyf
requencycont
rol
l
edpump
‘
6’thr
ough‘ 9’issubt
ract
edfr
om t
heinputusedtodi
spl
ay&logtankvol
ume..

When you add liquid to the tank, you tell the controller thenewtankvolumebyCal
i
brat
ingt
hesens
ori
nput‘
H’
t
hrough‘N’usedasanInventory target.
Anysensorinputori nput s‘H’thr ough‘ N’maybeusedt ocal
cul
atev
olume.

If more than one pump is drawing from the same tank:

1. Use the same Inventory sensor location for each pump & measuring meter
2. Refer to the previous Copy_Volume application note.

5.3.2 Typical Feed Verify Applications

Verifying an Inhibitor Feed

The inhibitor pump controlled by relay 1, has a device on its output that provides a contact closure every time
t
hepumps t
rokes.We’ regoi ngtousei ttov erif
yt hatwe’ r
eact uallyf eedingi nhibit
or.
We’v eenabl edunusedmet erinput‘ Q’,andnamedi tInhibitor Verify.

We’
veconf
igur
edInhibitor Verify Q with Compensation = Feed Verify and Verify Output = 1:Inhibitor.
We’
vel
eftt
heWait-to-Verify at the default 30 seconds.

Each time the Inhibitor Pump turns ON, the controller verifies that a contact closure is measured by Inhibitor
Verify Q every 30 seconds or less. 30 seconds ensures that evenatal owst roker ate,we’l
lseeac ontact
cl
osur eev ery30secondsunl esswe’ vel ostpri
me,empt iedt hedr um,bl oc kedaf eed…

If Inhibitor Verify Q does not measure a contact closure every 30 seconds while the Inhibitor Pump in ON,
Q will alarm.

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 AEGIS Technical Manual
5.3.2 Typical Feed Verify Applications cont.

Verifying a Bleed
We’ r
eusi ngthebl eedi nt hisex ampl e,butt
hesamemet
hodcanbeusedt
over
if
ythatanyv
alv
eorsol
enoi
d
actually operated and flow is occurring.

Debris occasionally blocks the bleed & whileweal

arm onhi
ghconduc t
iv
it
ywe’
dli
ket
oknowassoonast
he
bleed fails.
We’ veusi ngt
heex i
stingbleedmet erinput‘ ,namedBleed Volume.
P’

We’ veconfi
guredBleed Volume P with Compensation = Feed Verify and Verify Output = 2:Tower Bleed.
We’ veextended the Wait-to-Verify from the default 30 seconds to 300 seconds or 5 minutes.
Bleed Volume P is a 10 Gallons/contact meter & it takes some time after the bleed opens to measure 10
Gallons.

Each time the Bleed turns ON, the controller verifies that a contact closure is measured by Bleed Volume P
every 300 seconds or less.
If Bleed Volume P does not measure a contact closure every 5 minutes while the Bleed in ON, P will alarm.

Note: Feed verify compensation does not prevent meter P from being used elsewhere in the controller for
control, ppm calculations, O:P sequential feeds and P may be copied to other meters to sum discharge.

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 AEGIS Technical Manual
5.4 Frequency Controlled Pumps
5.4.2 Feed Rate Setting

Thecontroll
erknowst hepump’ smL/ st
rokeandmax imum s t
roker ate (Maximum SPM).
Once you select the pump feed method or control mode, the controller sets the optimum Pump Speed.

Modes User Sets Pump Speed

pH:
Sensor TurnOFF : As the tower cycles up, the pH rises.
Controlled pH or ORP setpoint The acid pump is OFF at pH < TurnOFF.
The pump speed increases linearly between TurnOFF
pH 100%ON : and 100%ON setpoints.
pH or ORP setpoint ORP:
ORP As the tower operates bleach is consumed and the ORP
falls.
The hypochlorite pump is OFF at ORP > TurnOFF
Proportional control. The pump speed increases linearly between TurnOFF
and 100%ON setpoints.

Measure: The tower make-up meter measures volume.

Water Meter Volume measured on meter The controller turns ON the pump at Maximum SPM,
ppm adding the volume required to meet the ppm setpoint.
Controlled Feed: Example: Measure 250 Gallons, Feed 125 ppm
ppm of product to feed
Bleed
& Feed mL/minute setpoint Inhibitor Pump ON when Bleed Solenoid ON.
Inhibitor
Bleed Inhibitor pump feeds at maximum SPM as soon as bleed
then Feed mL/minute setpoint solenoid turns OFF.
Inhibitor Volume fed proportional to time bleed solenoid ON.

Base Pump feeds at user set rate unless flowswitch turns OFF
Feed mL/minute setpoint feed.

Biocide Start Day# & Time

Feed Feed Volume Pumps user set volume at maximum SPM after Prebleed.
Events
Timed User sets cycle period in Pumps user set volume (1mL to 10L) at maximum SPM
Cycling minutes and ON volume in mL. at the start every user set period if above TurnON
setpoint.

Contact Set TurnON seconds TurnON@ user set seconds after contacts close &
Controls TurnOFF seconds di
splay‘ ON’
Turn OFF user set seconds after TurnON .
Fed at maximum SPM.

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 AEGIS Technical Manual
5.4.2 Technical: Frequency-Stroke Controls

1 Gallon = 3785 mL. Set pump frequency control to External & Stroke to 100%
GPH = Gallons per hour GPD = Gallons per day

Pump Defaults –User Adjustment Range & Resolution

Pump default mL/stroke is set for a 40psi head, typical for cooling tower chemical injection piping.
The user mL/stroke adjust is limited to +25% and –70% for ProMinent pumps.
TheusermL/ s t
rokeadj usti slimitedt o0. 01mL/
s trokeand10ml /st
rokefor‘ Ot
her’t ypepumps .
In both cases the adjust resolution is 0.01mL

‘
Other
’ty
pePumpspm r
atesar
eli
mit
edt
oami
ni
mum of50 spm and a maximum of 400 spm

Maximum Feed Rate

Apump’smax i
mum f eedratedisit
’sr atedmax i
mum s t
rokes/ minut exmL/ stroke.
Example: A ProMinent 1602 pump is rated 180spm with a default of 0.24 mL/stroke
The maximum feed rate for this pump = 180 x 0.24 x 60 = 2592 mL/hour,
0.685 GPH, 15.44 GPD
At the –70% minimum user adjust: 0.78 L/hour, 0.2 GPH
At the +25% maximum user adjust: 3.24 L/hour, 0.856 GPH

Minimum Feed Rate or Turn Down

The minimum pump frequency is set to 0.1 SPM; a turn down of 1800:1 for a 180 SPM pump
and 2400:1 for a 240 SPM pump.
The 0.1 SPM limit turns the pump drive LED ON for 5 minutes and OFF for five minutes; a maximum for an
observer visually verifying that a pump is stroking.

Minimum feed rate only applies to pumps that are controlled by analog sensors; pH, ORP, temperature, flow
rat
e…
Other pump controls operate at either the user set mL/minute or MAX SPM, so minimum feed rate is not
applicable.

Control Resolution
Control resolution = 1mS. I 1mS defines the precision of variable frequency control
Example: At 180 spm, a 1mS control resolution is 667 feed rates
At 10 spm, a 1mS control resolution is 6000 feed rates

As the example clarifies, control resolution is more important at high pump speeds.
Between 179 and 180 spm, there are 667 possible feed rates.

For a pump operating at 400 spm, the control resolution 150 feed rates

Setpoint Resolution
Setpoint
sf or‘ BaseFeed’ ,‘Bleed&Feed’and‘ Bl
eedt henFeed’mL/minute have 0.01mL resolution.
The resolution limit matches the user adjustable mL/stroke resolution

Setpointsf or‘ppm’ar ei nt
eger s.
Setpoints for volume meters are integers @ user set resolution.
Setpoints for biocide feed volumes are 0.01G resolution.

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 AEGIS Technical Manual
5.4.2 Technical: Frequency-Stroke Controls cont.

Setpoint Range Response

When the user adjusts the mL/minute feed setpoint OR selects a new pump OR adjusts the pump mL/stroke
setting, the controller verifies that the new setting or pump can deliver the required feed rate.

If the pump cannot deliver the required feed rate to meet the current setpoints, the controller sets the pump to
its maximum feed rate and notifies the user that the pump is maxed.

Volume Accuracy
For most applications, the default mL/stroke accuracy is applicable since users will adjust feed rates based on
wet chemistry test results. In this context, repeatability and linearity are more important for concentration
control than mL/stroke accuracy.

Error sources extend beyond the pump control accuracy to the precision of feed chemical blending, wet
chemi str
yt estaccuracy&r esoluti
on…

1. If your wet chemistry shows a 10% higher than expected ppm. Lower the mL/stroke setting for the
inhibit
orpumpby10%.Don’ tchanget hef eedset points.

2. If you are interested is tracking down ppm error sources, start by pumping 100mL from a graduated
cylinder and adjusting the pump mL/stroke to correct for the displayed increase in volume pumped.

5.5 Password Security

5.5.1 Overview

AEGIS controllers use 4 levels of password for controller access and to stamp the activity log:
Public Operator Maintenance Administrator
Refer to Section 6.5.4 for default user IDs and passwords.

Passwords are defaulted OFF for keypad users and ON for browser users.
Passwords cannot be turned OFF for browser users.

There are 7 user configurable passwords which are distributed between Operators & Configurers.

Passwords are a maximum of 9 letters and numbers and are case sensitive. The controller blocks the use of
HTML delimiter characters by limiting password content to letters and numbers only.

The controller blocks duplicate passwords since the password identifies the user on keypad log in.

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 AEGIS Technical Manual
5.5.2 Password Level Activities

Password Level Activities Notes

Public Views current state and clears alarms, Password not required for keypad or
select System or Diagnostic view. browser use.
1 per AEGIS
Cannot adjust or edit. Browser access to controller wide alarm
reset only.

Operator Calibrate sensors. Prime Pumps. Can edit own user ID & password.
Set 4 & 20mA levels.
1..7 per AEGIS Keypad users, password only editing.
Changes setpoints and feed rates.
default 4 Controller default user ID is Operator1 thru
Can view but not edit all controller Operator4 with default passwords 1..4.
configure level settings

Configure Configure controls, interlocks and Can edit own user ID & password.
blocking.
1..7 per AEGIS Keypad users, password only editing.
Sets sensor compensation, feed
default 3 alarms & limits. Controller default user ID is Configure5 thru
Configure7 with default passwords 5..7.
Sets biocide timing, Prebleed, Lockout
& cycle days.

Zeroes water meters

All Operator Activities

Administrator Set IP address and network Browser: Can define other users as
parameters. Operator or Configure
1 per AEGIS
All Operator & Configure Activities Cannot view other users passwords.

Canedi
townpasswor
d,def
aul
t‘AAAA’

Cannotedi
t‘
Admi
n’useri
d

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 AEGIS Technical Manual
5.5.3 Browser Passwords & Lockout

After 5 unsuccessful attempts to log on, the controller locks out both Ethernet and modem access
Locked out users will see an Alarmed status message in place of Password Incorrect .

Browser & modem resets at 7:00AM or when AC power OFF/ON.

Therefore the maximum lockout time is 24 hours and the minimum is less than a minute.

This feature blocks scripting attacks on controllers and cannot be disabled.

There is no limit on the number of keypad password attempts.

Changing all passwords from their default values is strongly recommended for Ethernet and modem connected
controllers.

Passwords can be reset to the factory default by logging on as the Reset Pswrds user.
Refer to Section 6.5.5

5.5.4 LCD Passwords

Passwords are defaulted OFF for keypad users.

The System/Password menu item does not display unless System/Configure has turned passwords ON.
Once passwords are turned ON, only the administrator can access System/Configure to turn Passwords OFF

If passwords are ON, you are prompted with the required password level; Admin / Configure / Operate when
you attempt to execute a command which reconfigures the controller.
Passwords are not required to view the current state.

Default Passwords & User IDs

User Type User ID Default
Password
Operator Operator1 1
Operator2 2
Operator3 3
Operator4 4

Configure Configure5 5
Configure6 6
Configure7 7

Administrator admin AAAA

Kepypad-LCD access cannot change User Type or ID.

NOTE1: If you are going to use keypad passwords, your first action after turning passwords ON should be to
changet headminandal lotherpasswor dssinceleav inganypass wor dati t
’sdef aul
tvalueby passespasswor d
protection.
NOTE2: Onl ythe‘ admi n’usercanl oadanewcont rollerv iew-configuration.

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 AEGIS Technical Manual
5.5.5 Password Reset

Contact Aquatrac with the controller serial number to obtain a reset password which resets all passwords to
the Section 5.5.4 factory defaults.
Proof of controller ownership is understandably required.
AEGIS controllers have no backdoor or super user password.
If you forget the password, this is the way to recover controller access.

5.6 Relay & Frequency Controls Comparison

ON/OFF Controls :
Relays R1 to R5 are used for ON/OFF controls.
The relay switches 120VAC ON or OFF, powering pumps, solenoids and motorized valves.

Frequency Controls :
P6 to P9 pulse outputs control pump frequency. The pump is always plugged into an AC supply and the
pumping rate is set by the frequency of pulses from the controller.

Modes Frequency Controls ON/OFF Controls

Sensors: Sensors:
Control Setpoints are TurnOFF & 100%ON Setpoints are TurnOFF & TurnON
Setpoints Proportional variable frequency control. Relay is OFF or ON.
Meters: Meters:
Setpoints are ppm & volume. Setpoints are volume & ON time.
Contact Sets: See Notes 1 Contact Sets: See Notes 1
Setpoints are seconds Setpoints are seconds.
& feed volume In mL TurnON@ user set seconds after contacts
100%ON @ user set seconds after contacts close.
close then feed setpoint volume. Turn OFF user set seconds after ON.

Up to four Sensors Up to four Sensors

Control OR up to four Water meters OR up to four Water meters
Equations OR one Contact Set. OR one Contact Set.
Sensors mayuse‘ +’,
’ ,
-‘’
x’or‘
/’oper
ators
. Sensors mayuse‘ +’,’,
-‘’
x’or‘ /
’oper
ator
s.
Watermeters mayuse‘ +’,sum operator
. Watermeters mayuse‘ +’
,sum &‘ :
’,
sequential operators.
Timed User sets event volume. User sets ON time.
Events Event ends on volume fed Event ends when time elapsed.
Data Logs volume fed in each log interval Log ON time in each log interval
Logging
Feed Limit = Volume per Feed @ MAX SPM Limit = Time ON per actuation
Limits Limit = Volume/Day Notes 2 Limit = Time ON /Day Notes 2
Fail A watermeter input must measure a count A watermeter input must measure a count
to Feed every user set seconds at any non zero within a user set seconds of turning on the
or Bleed control frequency. Notes 3 control relay. Notes 3
Control ‘
Away s’ Rising, Falling & Between setpoints.
Method OR OR
‘
Dur ingEv ents’ Rising, Falling & Between during events.

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 AEGIS Technical Manual
5.6 Relay & Frequency Controls Comparison cont.

Modes Frequency Controls ON/OFF Controls

Blocking Up to 4 Relay or Frequency controls may Up to 4 Relay or Frequency controls may
block . block .
Blocks on any Relay ON or any Frequency Blocks on any Relay ON or any Frequency
at a non-zero SPM. at a non-zero SPM.
Interlocking Up to 4 Contact Sets may interlock.. Up to 4 Contact Sets may interlock..
Contact Sets may be ORed or ANDed Contact Sets may be ORed or ANDed
Bleed & User sets mL/minute. Feed ON for user set % of every 5 minutes
Feed Feed ON when bleed ON. that bleed is ON
Controller blocks setpoints greater than
pump mL/min x MAX SPM
Bleed then User set mL/minute on Bleed ON time to User sets % of 5 minutes of each bleed ON
Feed calculate volume owed. time.
Feeds at MAX SPM when bleed turns OFF Feeds after bleed turns OFF.
% Time User set mL/minute User sets % of every 5 minutes ON time.
or Controller blocks setpoints greater than
‘BaseFeed’ pump mL/min x MAX SPM
PreBleed User sets Prebleed time & conductivity User sets Prebleed time & conductivity
Lockout limits. limits.
User sets Lockout time. User sets Lockout time.

Captured Not applicable User sets SAMPLE, MEASURE,

Sample BLOWDOWN & WAIT times.
Time Not applicable Pump ON time reduced as sensor
Modulation approaches TurnOFF setpoint.
Timed User sets cycle period in minutes and ON User sets cycle period in minutes and ON
Cycling volume in mL. time in minutes.

Holding User sets holding time in minutes User sets holding time in minutes
Time Sensor value averaged over the holding Sensor value averaged over the holding
time. time.
Feed Meter control. Not applicable to Pumps Meter control. Not applicable to Relays
Verification Notes 3 Notes 3
Variable Not applicable User sets three cycles of concentration
Cycles setpoints and a maximum conductivity.
Pump Type User selects Pump Type which sets default Not applicable
Selection mL/stroke & Max. SPM..
‘
Ot her’t
y peal l
owusert osetMAXSPM.
All types allow user to modify
mL/stroke.
Checks that existing feed rates are possible
when user changes pumps or set to MAX
SPM and alarm message if feed rate
modified.
Pump changes update the event log.
Copy Sums to water meters. Not applicable
Volume to Subtracts from Sensors (Inventory)
Notes 4

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 AEGIS Technical Manual
5.6 Relay & Frequency Controls Comparison cont.

Notes
1. Contact Sets
Runs once per controlling contact closure.
In addition to being able to use Contact sets to turn ON & OFF relays and frequency
controls, contact sets can have the following compensation:
Mirror:
Contact set Closed when user set output ON and OPEN when output OFF.
May be used with phantom contact sets U to Z.
If used with inputs O to T, the physical input is ignored by the controller.
Invert ON/OFF:
Switches the logical sense of the contact set so you can control on contacts opening
and if you also select Mirror, a relay turning OFF
Applications: Allows a control only when relay changes state
Flushing or priming feed headers.
Day tank fill, drain, filter backwash or mixer sequence controls
Neutralization timing controls.

2. Feed Limits
Users may set OFF on Alarm, turning OFF a Relay or Frequency on limit.
Users may also set Midnite Reset to reset a feed limited output at midnight

3. Feed Verify Bleed Verify

Users may set Feed Verify compensation on any water meter by selecting the Relay or
Frequency output and the Wait-to-Verify delay to alarm in seconds.
Allowing a variable delay to alarm widens applications and supports very low feed
rates.
User selects Verify Output pump, valve or solenoid.
User selects optional Inventory Location and fed volume is subtracted from the tank
volume.
4. Copy Volume to
Users may copy the volume pumped to any water meter input, summing the pumped
volume with the meter-measured volume.
Meters may also be copied to other meters
Inventory
Users may also copy the pump volume to a sensor input where the volume pumped is
subtracted from the tank volume.
More than one frequency controlled pump volume may be subtracted from a single
tank.

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 AEGIS Technical Manual
5.7 System Alarms & Indicating LEDs
5.7.1 System Alarms
Alarms not specific to any sensor or control.

Name Alarm Message & Cause Effect

Relay 1-5 Fuse “Fuse opens” 120-230VAC Pumps, solenoids & valves OFF.
AC line Fuse faults, opens Data logging on R1 to R5 shows zero ON time.
@ 5 Amps to the solenoids, valves & Variable frequency controls continue to operate.
pumps powered by Relays 1 to 5
15VDC External “Low Alarm” Correct wiring. Remove defective sensor.
Wiring errors or a fault on any sensor 15VDC thermal fuse auto-recovers.
powered by the controller 15-20VDC While alarmed: sensors, meters and current loops
‘
DCPowerOut put’suppl y powered by the 15VDC supply will not operate.
Internal 2.5V “Out of Range” Used to auto-calibrate all sensor measurements to
Sensor, meter or contact set wring remove power supply drift error.
error or driver card fault. All sensor measurements stop auto-calibration.
Power-on fault “Controls Removed” The pump or solenoid controlled by the removed
One or both sensor driver cards have sensor turns OFF. Re-configure the control.
been removed or type changed.

5.7.2 Indicating LEDs

Name Location Function

ON when the controlling processor on the upper measure circuit
Running Front Measure board board is communicating with processor that measures water
Right side center meters and contact sets and supports a USB connection..
OFF when the USB password is accepted & the controller is
OFFLINE.

ON when the controlling processor on the upper measure circuit

RUN Back Power board board is communicating with the lower power control processor.
above the NEUTRALS ON when the AC line fuse powering R1 to R5 is NOT open.
wiring block OFF when the USB password is accepted & the controller is
OFFLINE.
R1, R2 Lower Power board ON whenever the Relay is ON.
R3, R4 Above Relay1 to Relay5 ON when the NO wiring terminal is at the AC power voltage.
R5 AC wiring terminals

Lower Power board ON for 50% of the pump frequency period.

P6,P7 Above Pump6 to Pump8 Mirrors the time that the electronic contact set pulsing the pump
P8,P9 control is closed.
Cable terminal Example: Apumpr unningat10SPM woul dhavei t’
sindicati
ng
LED on for 3 Seconds and OFF 3 Seconds since 10
Strokes/Minute is a 6 second period & 5.5% of rated for a
180SPM rated pump.
LCD Backlight ON when the controller is AC powered and its internal 5VDC
supply is @ 5VDC.

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 AEGIS Technical Manual
5.8 Units for Volumes & Temperatures
5.8.1 Metric –US Units Selection

Controller units are selected by the Metric/US Units keypad and/or browser switch.

Although the increasing use of ppm controls and frequency controlled pumps moves more sites to Metric units,
the familiarity with gallons of feedwater make-up and GPM recirculation rates indicates that sites will continue
to use both unit systems.
This application note details how the controller applies the Metric/US Units switch setting.

Warning: Sensor values, meter and pumped volumes are logged with the units applicable at the time of log
entry. Typically the Metric/US Units switch is set once, when the controller is commissioned, since changing
units causes problems with interpreting data logs, & adjusting feed, timeout and alarm setpoints.

5.8.2 Water Meter Volumes

The measured and displayed water meter volumes, volume per contact, K Factor and the high and low alarms
are all in the units set by the Metric/US Units switch.

Although the user set units for each volume meter and sensor input are ignored, you may mix volume units as
l
ongasy oudon’ tcombi nev olumesmeasur edwi t
hdi ff
erent units.

US Units: All volumes measured in Gallons.

Metric: All volumes in Liters

Zeroing a Water Meter

Switching a water meter to a contact set and then back to a water meter will zero the meter and set the default
units to L or Gal, depending on the Metric/US Units switch.

Rate-to-Volume
The rate displaying on the sensor input converts to a volume based only on the Rate Minute / Rate Hour switch
setting. If you are measuring rate in GPM or LPM then the volume logged by the target water is in Gallons or
Liters respectively.
Note that in both examples the volume units are set by the measured rate units and not by the Metric/US
Units switch.

Example1: A stream demand meter measuring 1200 lbs/hour, would increase the volume
on the target meter by 20 lbs per minute, 28,800lbs/day.
Sett heuni tsont het argetmet erto‘lbs’
.
Example2: An RO waste meter measuring 10 GPM, would increase the volume
on the target meter by 10 gallons per minute, 600 gallons for every hour.
Set the units onthet argetmet erto‘gal’.

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 AEGIS Technical Manual
5.8.2 Water Meter Volumes cont.

Copy Volume to:

Copying between water meters uses the units set by the Metric/US Units switch.
Copying a volume from a frequency controlled pump to a water meter converts mL to Gallons if the Metric/US
Units switch is set to US Units.
Copying a volume from a frequency controlled pump to a an Inventory sensor input, converts pump mL to
either Liters or Gallons depending on the Metric/US Units switch setting.

5.8.3 Pump Volumes

Frequency controlled pump volumes are measured in mL.

The Metric/US Units switch selects the display units for volumes greater than 100mL.

Frequency controlled pumps are specified in mL/stroke with mL/stroke calibration limits enforced by the
controller.

Unit Conversion: mL to Gallons multiply mL x 0.0002642

Liters to Gallons multiply L x 0.2642

5.8.4 Inventory Volumes

Tank inventory volumes are calculated using the units set by the Metric/US Units switch.
The user set units for a sensori
nput‘H’ t
o‘ N’usedf orI nventor yareignor ed.

The controller converts the mL pumped by the frequency controlled pumps to either Gallons or Liters,
depending on the setting of the Metric/US Units switch.

If you are using a water meter input volume to calculate inventory, the controller assumes that the meter is
measuring in mL. The controller converts the measured mL to Gallons or Liters prior to adjusting the inventory
level.

If you are using pumped volume from a frequency controlled pump to calculate inventory, the controller applies
the correct conversion when calculating inventory based on the setting of the Metric/US Units switch.

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 AEGIS Technical Manual
5.8.5 1mL/Pulse Meters

In addition to the Tacmina 1mL/pulse feed meters, there are a number of devices and some pumps, which
provide a contact closure or pulse on pumped volume. In all cases, the controller assumes that the volume
represented by the pulse or contact closure is measured in mL.

Set the Volume/contact for the Tacmina or volume measuring device to the correct mL value.
The controller will make the correct assumptions.

The mL assumption is required for two controller sensor compensations & not required for type of control:
1. Inventory: The drum or tote volume is reduced as the volume meter measures.
2. ppm: The volume of inhibitor pumped in mL is used to calculate ppm using the volume of make-up (in
Gallons or Liters) and the cycles of concentration.
3. Sequential Meter Feed: The O:P sequential control equation may use either a Tacmina type volume
meter(mL) or a bleed meter(L or Gallons) for meter ‘P’. In either case, control is unaffected by either
volumemet er’suni t
s.

Warning: Do not sum volume meters with different units. The result is meaningless.
For example you can sum make-up meters and you can sum feed verify meters, but you cannot sum a
Make-up meter (Gallons or Liters) and a Feed Verify meter (mL).

5.8.6 Temperatures

Temperature default units are set by the Metric/US Units switch for each input, which measures a temperature
and is then used for each conductivity or pH sensor, which may be temperature compensated.

Default offsets & gains for thermal sensors are set to the defaults corresponding to the Metric/US Units
switch.

USUni
ts:Temper
atur
euni
ts=‘
F’. Met
ri
c:Temper
atur
euni
ts=‘
C’.

Warning: Remember that even if you change the default units on a temperature input, the controller internally
applies the units set by the Metric/US Units switch.

Aquatrac strongly recommends that you do not change the default units on any temperature used for control or
for temperature compensation of conductivity or pH. Errors in both temperature calibration and tracking over
temperature for conductivity and/or temperature compensated pH will result.

5.8.7 User Assigned Units

User assigned units have no effect on controller volumes, inventory, ppm and temperature compensation
calculations.

You are free to assign whatever units you wish and to mix unit types in any one controller bearing in mind how
the controller handles unit conversions in Metric & US Units modes.

Ifyouneedt
oov
err
idet
heuni
tsonanyi
nput
,youcanedi
ttheOFFSET&GAI
Nthat
’sappl
i
edt
othet
arget
input.

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 AEGIS Technical Manual
5.9 XML: URL Encoded Requests
This application note details the syntax used for URL encoded XML data log upload commands.

URL encoded commands are formatted as: URL/taco.cgi?F0 = Field0Value & F1 = Field1Value ….
Where URL = IP address of the AEGIS controller.

Example using the AEGIS default IP: http//10.10.6.106/taco.cgi?F0=CL&F1=AAAA&F2=G

Logs in as admin &requestsSensorI nput‘ G’logusi ngt hedef aultv
aluef
orF3

Command Command# : Syntax : Password Function & notes

CL CL: Communications Log F1 Any valid password @ Operate, Configure

F0 F1 or Admin level. Password also logs into the
CL [ Password ] controller by setting the userid cookie. One
F2 valid password provides both log & browser
[ I/O A..Z or 1..9 or 0 = system ] access.
F3
[ Report Type, Defaults to log ] F2 Inputs A..Z as caps. Outputs 1..9
F4 Defaults to zero & system
[ Number of log entries ] F3 No F3 value gets the log for an I/O
or default System report.
F4 No F4 value gets all entries
Most recent entry first allows data base
updates based on log period & most
recent data base entry.

Action on incorrect password: XMLHeaderonl yconf irmscommandr ec’d.Nocont roll

erdatas ent .
Five incorrect passwords disconnect until 7:00 AM. Identical to password response on browser log-in
Action on disabled I/O: XML header only.

F3 F2 Field Notes
Value
F2 = A..Z, 1..9 Data logs are most recent first.
0 Header & Data log
or‘
none’ F2 = 0, System Request enabled parameters first as
35Char ac terenabl
edstri
ng‘A..Z1..9’ http//10.10.6.106/taco.cgi?F0=CL&F1=AAAA&
Wi thdi sabl edI/
O as‘spaces. F2=0
Alarmed I/O string
+‘ SYS’i fSy st
em Alarmed Non-zero F3 values will be used for future
reporting.

Action on illegal F3 values: Samer

espons
easz
eroor‘
none’
.

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 AEGIS Technical Manual

6. Applications
6.1 Adjusting Inhibitor Feed with Varying Cycles
6.1.1 Problem

Varying Cycles changes the cooling tower cycles of concentration as the make-up conductivity varies.
You are likely to require more or less inhibitor feed at different cycles of concentration.
This application explains how to adjust the inhibitor feed rate as the make-up conductivity varies.

The inhibitor is fed proportional to make-up or bleed volume, controlled by a make-up or bleed water meter.
As the load on the tower increases, more water is required & more inhibitor is fed to maintain a constant, target
ppm in the recirculating cooling water.

Note: This solution can be generalized to applications where you need to use a continuously reading sensor
(t
emper at ure,pH,cor rosi
onr ate,ORP…)t omodi f
yaf eedr atebasedonani ncr ement alvolume
measurement.

6.1.2 Setup: Controller Configuration

I/O Usage Function, Configuration Notes

‘
O’TowerMake-up Measures make-up water volume. Use‘
P’i
fbl
eedmet
ercont
rol
l
ingi
nhi
bi
tor
‘
E’Make-up Cond. Measures make-up conductivity.
‘
6’I
nhi
bi
torPump Cont
rol
l
edby‘
E’. Use‘
1’i
fON/
OFFi
nhibitor pump
I
nter
loc
kedby‘
X’
Setpoints reflect the expected range of
make-up conductivity.
‘
9’FeedTr
ack Unusedpumpcont
rol
l
edby‘
O’ Sett hepump‘ 9’andpump‘ 6’pumpt ypest
o
be the same so that both max. SPM &
ml/stroke match.
‘
X’FeedSt
ate ONwhen‘
9’FeedTr
ackON ‘
Mir
ror
ing’
tur
nsON‘
X’whenev
er‘
9’i
sON.
‘
X’i
sconf
igur
edt
omirror ‘
9’ ‘
X’isaphant
om inputenabl
edt
otr
ackt
he
st
ateofpump‘ .
9’

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 AEGIS Technical Manual

6.1.3 Solution

Weconf
igur
edt
heAegi
scont
rol
l
ersasdet
ail
edi
nSect
ion6.
1.2&nowwe’
l
laddsi
tespeci
fi
cset
poi
nts.

Example: We expect the tower make-up conductivity to vary between 500uS and 100uS.
At 500uS we need to feed @ 50ppm and at 100uS we need to feed at 20ppm.

Control Configuration Notes

‘
9’FeedTr
ack Measure volume = 100 Gallons Set to the feed rate @ 500uS, the maximum
Then feed = 50 ppm make-up conductivity
‘
6’I
nhi
bi
torPump 100% ON = 500uS Setpoints are uS but the difference between
Turn OFF = -167 uS setpoints is set by the target ppm range.

ev
When the make-up conductivity is 500uS, pumps 9 & 6 feed the same amount; what er
’sr
equi
redt
omai
ntai
n
50 ppm of inhibitor.

At 100uS we need to feed 20ppm which is 20/50 or 40% of the 500uS rate.
The full range of control from 0% to 100% is therefore (500 –100) / 0.4 = 667uS.
If 500uS is 100% than 0% = 500uS –667uS = -167uS.

Let’scheck:
At 300uS we should be feeding @ 35ppm or at 70% of the 50ppm rate.
Actual pump speed = (300 +167) / 667 x 100% = 70%., OK!

6.1.4 Summary & Options

We’
reusi
ngasensorv
aluet
omodi
fyt
hef
eedr
ateofachemi
cal
fedpr
opor
ti
onalt
oawater meter volume.

We’
veusedasi mpl eex ampl ehowev ert
her earemanyper mutati
onst hataddf lex
ibi
li
ty :
A. Youcoul df r
equencyl i
mi toneoft hepumpsbyset ti
ngi t’
stypet o‘ot
her’.Handyi fal
lyouhav
eisan
oversized pump & usually preferred over reducing the stroke.
B. You can modify the ml/stroke for the Feed rack and/or Inhibitor Pumps.
C. You can control the Inhibitor pump on the difference between Temperature & Make-up Conductivity. As
the temperature increases, the difference decreases & you feed more inhibitor.

7/08 43
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 AEGIS Technical Manual
7. Sensor Driver Card Manuals
7.1 CT: Conductivity Temperature
Safety
5 VDC, 1V AC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.1.1 Installation
Services
The CT driver measures conductivity and temperature, connecting to a single immersed sensor.
Usually the sensor is installed in a cooling tower recirculating loop, although thermally compensated sensors
maybei nstal
ledincondensat es tr
eams ,RO pi ping,downst ream ofsampl ecool er
sonboi l
erbl
owdowns…
Up to2CT’ smaybei nstalledi nanAegi scontrollerinaddi ti
ont ot hef ixed‘A’&‘ B’input swhi
chcanbe
configured to be a third CT driver.
Thermal compensation of conductivity is provided by the controller software.

Card Installation
1. Turn OFF the controller AC power
2. CTdr ivercar dsmaybei nstal l
edi nei thert heSensor s‘C’&‘ D’ orSensor s‘E’&‘ F’s lot.
3. Turn ON the controller after installing the CT Driver and the controller will auto-configure, displaying both
conductivity and temperature on the LCD display and browser.

Sensor Types
Aquatrac type A261200, A261205 cooling tower and A261016 hot water, boiler-condensate sensors
These sensors contain a 10mV/K type sensor rated up 125C.

Sensor Wiring
Red to S+
Conductivity sensor cabling may be extended up to 200ft / Black to S-
60m, using two pair AWG22 / 0.25 mm2, cable spliced to White to T+
the sensor cable using wire nuts or crimped connectors Green to T-
located in an electrical fitting or enclosure.

Do not install sensor cabling in the same conduit as AC

power cabling. S+ S- T+ T-
Rd Bk Wh Gn
Conductivity sensor cabling may share a common
conduit with other sensors, water meter and contact Part: CT
set cabling.

Conductivity
Temperature Conductivity
Sensor &
Temperature

>100uS
<100uS

Conductivities >100uS
greater than 100uS <100uS

Conductivities >100uS
less than 100uS
<100uS
7/08 44 ( Install jumper )

Aegis_Tech
 AEGIS Technical Manual
7.1.2 Configuration - Operation

Range Selection

Cooling towers –Waste Water –RO Streams:

The default range for the CT driver is >100uS. Installing a jumper on the
>100uS pins does not change the default range. Use this range for
conductivities from 200uS to 20,000uS. S+ S- T+ T-
Rd Bk Wh Gn

Condensate –Low Conductivity: Part: CT

Jumper the <100uS pins for conductivities in the 1 to 100uS range.
Constant pressure condensate conductivities may also be measured
with the single or dual B driver using sensors without thermal
compensation. Conductivity
&
Changing Ranges: Temperature
Turn the controller OFF before changing ranges
Controllers check range on power up, loading default
Offset and Gain on range change.

>100uS
<100uS

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 AEGIS Technical Manual
7.1.2 Configuration –Operation cont.

Diagnostics: Conductivity Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK C: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK Conductivity: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 1088 uS: Current measured conductivity, display user set units,
‘uS’def aul t.Display edwithusersetr esol ution
Period Maximum OK 1094 uS: Data from current log interval. Used to assess
controls.
Period Minimum OK 1082 uS:
Period Average OK 1086 uS:
Sample Size OK 426: Samples in Period Max. Min. & Average
Current Period OK 36 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Compensation OK OK Thermal Compen. / None:
Measured Level OK OK 184.9 mV: Raw sensor level in mV, before Gain & Offset after
ID Level correction.
Gain Multiplier OK OK 5.6420: Calibration adjusts Gain. Displayed Value = Measured
Level x Gain Multiplier + Offset Adjust
Thermal Compensation is applied after Gain & Offset if selected
Default Gain OK OK 5.6000: Factory default Gain. Gain selected by Input Card ID
Offset Adjust OK OK -35.0000: Offset. May be user adjusted.
Default Offset OK OK -35.0000: Factory default Offset. Offset selected by Input Card
ID
Input Card ID OK OK 77 mV: Drive level at >100uS range. Design level = 75mV.
1007 mV: Drive level at <100uS range. Design level = 1005mV.
Drive Level OK 0.0 mV: Unused in CT driver.

Range Default Gain Calibration Default Offset

Gain Span
>100uS 5.6 2.5 to 10 -35
<100uS 0.4 .25 to .55 -10

Calibration: A calculated gain outside of the Calibration Gain Span requires a user selected Override to
complete calibration.

Driver Verification Test:

Connect1Kohm r esist
ort o‘
S+’&‘
S-‘
.SetRanget
o‘>100uS’
. Measur
edLev
el=187.
5mV+/
-5mV

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 AEGIS Technical Manual
7.1.2 Configuration –Operation cont.

Diagnostics: Temperature Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK D: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK Temperature: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 78.47 F: Current measured conductivity, display user set units,
‘F’
/’C’ar edef aults.Di spl
ay edwi thusersetr esoluti
on.
‘Met r
ic’swi t
chsel ects‘C’asdef ault.
Period Maximum OK 78.55 F: Data from current log interval.
Period Minimum OK 78.30 F:
Period Average OK 78.45 F:
Sample Size OK 1320: Samples in Period Max. Min. & Average
Current Period OK 37 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None:
Measured Level OK OK 2988.1 mV: Raw sensor level in mV, before Gain & Offset.
10mV/K = 298.8K, 25.8C
Gain Multiplier OK OK 0.18: Gain. May be user adjusted.
Default Gain OK OK 0.18: Factory default Gain. Gain selected Metric switch.
Metric Default Gain = 0.1
Offset Adjust OK OK -461.4: Calibration adjusts Offset. Displayed Value = Measured
Level x Gain Multiplier + Offset Adjust. .
Default Offset OK OK -459.4: Factory default Offset.
Offset selected by Input Card ID
Metric Default Offset = -273
Input Card ID OK OK 3003 mV: Ignored by controller, card ID set by conductivity
input.
Drive Level OK 0.0 mV: Unused in CT driver.

Units Default Gain Calibration Default Offset

Offset Span
F 0.18 -430 to –590 -459.4
C / Metric 0.10 -253 to -293 -273.0
Option Set

Calibration: A calculated offset outside of the Calibration Offset Span requires a user selected Override to
complete calibration.

Driver Verification Test:

Connect1Kohm r esist
ort o‘
T+’&‘T-‘
.Measur edLev el=680+/
-5mV
Measured Level = 680uA thermal sensor drive x 1K ohm

7/08 47
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 AEGIS Technical Manual
7.1.3 Specifications

Range / Function Drive

>100uS Resolution: 1uS 75mV AC
100 –10,000uS Accuracy: +/-5uS

>100uS Tracks reduced resolution 75mV AC

10,000 - 20,000uS & accuracy

<100uS Resolution: 1uS 1005mV AC

1-100 uS Accuracy: +/-1uS

Temperature Resolution: 0.1F / 0.1C 680uA

32 –250F Accuracy: 1 F/C Constant current.
0 –125C 5 VDC MAX.
Temperature compensation of
conductivity is %/Degree from 70F
or 20C

Notes:
1. Accuracy stated after sensor calibration.
2. Excludes errors due to extending sensor cabling.

7.1.4 Revisions

Date Revision
5/31/07 Corrected 1.4 Sensor Wiring color coding to match corrected
driver card text.
Actual text on CT driver cards is correct and unchanged.
Previously, text inverted WHITE & GREEN

7/2/08 Reformatted for Aegis manual

7/08 48
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 AEGIS Technical Manual
7.2 CT: Boiler Conductivity
Safety
250mV AC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.2.1 Installation

Services
The B driver measures one or two conductivities.
Each of the two sensor drives may be jumper configured for boiler or condensate conductivity measurement.
Uptot wodualorsi ngl
e‘ B’dr i
versmaybei ns t
alledi
nanAegi scont roll
er.

Driver Card Installation

1. Turn OFF the controller AC power
2. Thesi ngl
eanddualBdr i
vercar dsmaybei nstall
edi nei t
hertheSensor s‘C’&‘ D’orSensor s‘E’&‘ F’sl
ot .
3. Turn ON the controller after installing the B Driver and the controller will auto-configure, displaying one or
both conductivities on the LCD display and browser.

Sensor Types
Aquatrac type A261000, A261001 & A261CHP boiler-condensate sensors

Sensor Wiring

Sensor cabling is
not polarized

S1 S1 S2 S2 S1 S1 S2 S2
Part: B Part: B

Sensor 2 Sensor 1 Part: OP Sensor 1

Dual Boiler
or Boiler
Dual Condensate or
or Condensate
pH or ORP
Boiler & Condensate
CND

CND

CND

CND
BLR

BLR

BLR

BLR

Sensor 1 Sensor 2 Sensor 1 Sensor 2

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 AEGIS Technical Manual
Sensor Wiring cont.

Conductivity sensor cabling may be extended up to 200ft / 60m, using single pair AWG22 / 0.25 mm2, cable
spliced to the sensor cable using wire nuts or crimped connectors located in an electrical fitting or enclosure.

Do not install sensor cabling in the same conduit as any AC power cabling, particularly cabling used to power
steam rated solenoids and/or motorized boiler blowdown valves.

Conductivity sensor cabling may share a common conduit with other conductivity & fail-to-sample sensors,
water meter and contact set cabling.

7.2.2 Configuration - Operation

Range Selection

Boiler Blowdown:
The default range for the B driver is BLR. Installing a jumper on S1 S1 S2 S2
the BLR pins does not change the default range. Part: B
Use this range for conductivities from 200uS to 10,000uS.

Condensate –Low Conductivity: Dual Boiler

Jumper the CND pins for conductivities in the 1 to 200uS range. or
Dual Condensate
Changing Ranges: or
Turn controller OFF before changing ranges Boiler & Condensate
Controllers check range on power up, loading default
Offset and Gain on range change.
CND

CND
BLR

BLR
Sensor 1 Sensor 2
S1 S1 S2 S2
Dual Boiler
CND

CND
BLR

BLR
Part: B No Jumpers
Sensor 1 Sensor 2

Part: OP Dual Condensate

CND

CND
BLR

BLR

2 Jumpers
Sensor 1 Sensor 2
Boiler
Boiler &
or
CND

CND
BLR

BLR

Condensate
Condensate Sensor 1 Sensor 2 1 Jumper
pH or ORP
CND

CND
BLR

BLR

Sensor 1 Sensor 2

Boiler
CND
BLR

No Jumper
Sensor 1

Condensate
CND
BLR

Jumper
Sensor 1

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 AEGIS Technical Manual
7.2.2 Configuration –Operation cont.

Diagnostics

Parameter LCD Browser Value : Use

Display
Sensor Location OK E: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK Boiler Conductivity: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 3148 uS: Current measured conductivity, displays user set
uni t
s,‘uS’def aul t
.
Displayed with user set resolution
Note: If the sensor is used for Captured Sample control of a
blowdown valve, this value and all log values update at the end
of the Measure period.
Period Maximum OK 3214 uS: Data from current log interval. Used to assess
controls.
Period Minimum OK 3091 uS:
Period Average OK 3162 uS:
Sample Size OK 231: Samples in Period Max. Min. & Average
Current Period OK 19 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None:
Measured Level OK OK 1062.3 mV: Raw sensor level in mV, before Gain & Offset after
ID Level correction.
Displayed in real time for sensors used for Captured Sample
controls.
Gain Multiplier OK OK 2.142: Calibration adjusts Gain.
Displayed Value = Measured Level x Gain Multiplier + Offset
Adjust

Default Gain OK OK 2.0000: Factory default Gain. Gain selected by Input Card ID
Offset Adjust OK OK 0.0000: Offset. May be user adjusted.
Default Offset OK OK -15.0000: Factory default Offset.
Offset selected by Input Card ID
Input Card ID OK OK 51 mV: Drive level at BLR, boiler range. Design level = 50mV.
206 mV: Drive level at CND, condensate range.
Design level = 208mV.

Range Default Gain Calibration Default Offset

Gain Span
BLR 2.0 10 to 0.5 -15
CND 8.0 12 to 3 -90

Calibration: A calculated gain outside of the Calibration Gain Span requires a user selected Override to
complete calibration. The wide span allows for the range of temperatures at the sensor.

Driver Verification Test:

Connect1Kohm r esist
ort o‘
S1’&‘
S1‘or‘
S2’&‘S2’
.
BLR Range, Measured Level = 129mV +/-5mV. CND Range, Measured Level = 520mV +/-10mV
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 AEGIS Technical Manual
7.2.3 Specifications

Range / Function Drive

BLR Boiler Resolution: 1uS 50mV AC
100 –10,000uS Accuracy: +/-25uS

CND Condensate Resolution: 1uS 208mV AC

1 - 200uS Accuracy: +/-2uS

Notes:
1. Accuracy stated after sensor calibration.
2. Exclude errors due to extending sensor cabling.

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 AEGIS Technical Manual
7.3 OP: ORP - pH
Safety
+/-1VDC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.3.1 Installation

Services
The OP driver measures ORP and pH sensors.
The driver can be configured to measure dual pH, dual ORP, pH & ORP, single pH and single ORP.
Uptot wodualsensorort wosi ngl
esensor‘ OP’dr i
versmaybei nstal
l
edi nanAegi scont rol
ler.

Driver Card Installation

1. Turn OFF the controller AC power
2. OPdr iv
ercar dsmaybei nst all
edi nei thertheSensor s‘C’&‘ D’orSensor s‘E’&‘ F’slot.
3. Connect the pH and/or ORP sensors to the driver field wiring terminals.
4. Turn ON the controller after installing the OP Driver and the controller will auto-configure, displaying the
installed sensor or sensors on the LCD display and browser.

Sensor Types
Aquatrac pH types A261100, A261102, SXT-HPP and ORP types A261105, ORP-FF, SXT-HPO
Generally, all ORP and pH sensors with a single coaxial cable may be used with the OP drivers.

Sensor Wiring
Bare Shield to '-'
Clear, center wire to '+'

1+ 1- 2+ 2- 1+ 1- 2+ 2-

Part: OP Part: OP

Sensor 2 Sensor 1 Sensor 1

Sensor, Entry & Sensor, Entry &
Dual pH or
Solution Ground Solution Ground
Dual ORP or pH or ORP
pH & ORP

ID ID
S2 S2
S1 S1
2O PO 2O PO

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 AEGIS Technical Manual
Sensor Wiring cont.

ORP sensor cabling may be extended up to 200ft / 60m, using single pair AWG22 / 0.25 mm 2, cable spliced to
the sensor cable using wire nuts or crimped connectors located in an electrical fitting or enclosure. Higher
int
er nali
mpedancepHs ensor ’
scabl i
ngcannot be extended more than 25ft, 10m.

Do not install sensor cabling in the same conduit as AC power cabling.

ORP, pH sensor cabling may share a common conduit with other sensors, water meter and contact set
cabling. Solution grounds are single conductor AWG18-22 / 0.25-0.75 mm2.

Warning 1: Do not install pH sensors without installing and connecting a solution ground. Unstable, drifting
pHs will occur if the solution ground is disconnected.

Warning 2:
Turn OFF the controller before connecting or disconnecting pH and ORP sensors.

7.3.2 Configuration - Operation

Sensor Set Selection

Changing Sensor Set:

Turn controller OFF before changing sensor selection jumpers.
Controllers check selection jumpers on power up, loading default
1+ 1- 2+ 2-
Offset and Gain on range change.

Part: OP

1+ 1- 2+ 2-
Dual pH or
Dual ORP or
pH & ORP
Part: OP

ID
S2
pH or ORP S1
2O PO

Dual pH
2O PO
No Jumper

Dual ORP
ID Jumper 2O
S2 2O PO
S1
2O PO pH & ORP
Jumper PO
2O PO
pH
No Jumper
2O PO

ORP
Jumper
2O PO

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 AEGIS Technical Manual
7.3.2 Configuration –Operation cont.

Driver Test Header

DVM
S1 = Sensor 1 mV x -1
millivolts S2 = Sensor 2 mV x -1
ID = Card ID Level
V COM

+ -

ID = Card ID Level
Dual pH 1150
Dual ORP 1345
pH & ORP 1450 ID
Single pH 1050 S2
Single ORP 1250 S1

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 AEGIS Technical Manual
7.3.2 Configuration –Operation cont.

Diagnostics: pH Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK A: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK pH Sensor: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 8.12pH:Cur r
entmeasur edpH,di spl ayusersetuni ts,‘
pH’
default. Displayed with user set resolution
Period Maximum OK 8.15 pH: Data from current log interval. Used to assess controls.
Period Minimum OK 8.05 pH:
Period Average OK 8.10 pH:
Sample Size OK 122: Samples in Period Max. Min. & Average
Current Period OK 18 minutes: Elapsed time in current log period
Log Period OK 15 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None:
Measured Level OK OK 62.3 mV: Raw sensor level in mV, before Gain & Offset after ID
Level correction.
Gain Multiplier OK OK 0.0170: User set Gain
Default Gain OK OK 0.0170: Factory default Gain, 59mV/pH
Gain selected by Input Card ID
Offset Adjust OK OK 7.2361: Offset. Calibration adjusts Offset.
Displayed Value = Measured Level x Gain Multiplier + Offset
Adjust
Default Offset OK OK 7.0000: Factory default Offset. Offset selected by Input Card ID
Input Card ID OK OK 1147 mV: Dual pH Design level = 1150 mV.
Single pH Design level = 1050 mV
PH –ORP Design level = 1450 mV

Sensor Default Gain Calibration Default Offset

Type Offset Span
PH 0.017 6-8 7

Calibration: A calculated offset outside of the Calibration Offset Span requires a user selected Override to
complete calibration.

Driver Verification Test:

Connect a pH sensor, center conductor to 1+ and shield to 1-. Immerse sensor into pH10 buffer and connect a
solution ground wire with an exposed wire end immersed in the buffer. Measured Level = 170mV +/-25mV

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 AEGIS Technical Manual
7.3.2 Configuration –Operation cont.

Diagnostics: ORP Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK B: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK ORP Sensor: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 321mV:Cur rentmeasur edORP,di spl ayusers etuni t
s,‘
mV’
default. Displayed with user set resolution
Period Maximum OK 340 pH: Data from current log interval. Used to assess controls.
Period Minimum OK 306 pH:
Period Average OK 318 pH:
Sample Size OK 411: Samples in Period Max. Min. & Average
Current Period OK 38 minutes: Elapsed time in current log period
Log Period OK 120 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None:
Measured Level OK OK 307.4 mV: Raw sensor level in mV, before Gain & Offset after
ID Level correction.
Gain Multiplier OK OK -1.0000: User set Gain
Default Gain OK OK -1.0000: Factory default Gain,
Gain selected by Input Card ID
Offset Adjust OK OK 13.612: Offset. Calibration adjusts Offset.
Displayed Value = Measured Level x Gain Multiplier + Offset
Adjust
Default Offset OK OK 0.0000: Factory default Offset.
Offset selected by Input Card ID
Input Card ID OK OK 1145 mV: Dual ORP Design level = 1344 mV.
Single ORP Design level = 1250 mV
PH –ORP Design level = 1450 mV

Sensor Default Gain Calibration Default Offset

Type Offset Span
ORP -1 +50 to -50 0

Calibration: A calculated offset outside of the Calibration Offset Span requires a user selected Override to
complete calibration.

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 AEGIS Technical Manual
7.3.3 Specifications

Function Notes
Input Range +/- 1000mV
0-14 pH

Resolution ORP: 0.1mV

PH: 0.01 pH

Accuracy +/- 0.1mV Requires installed solution ground

+/- 0.02pH for each measured sensor.

Input Impedance > 500 MOhm Fully differential.

10M ohm power OFF input
resistance

Notes:
Accuracy stated after sensor calibration.

7/08 58
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 AEGIS Technical Manual
7.4 CI: Dual 4-20mA Current Input
Safety
30 VDC maximum on field wiring terminals.
30 VDC maximum on internal card surfaces.

7.4.1 Installation

Services
The CI driver measures two 4-20mA current loops.
The CI driver terminates each current loop with 50 ohms, referenced to electrical ground.
Each 4-20mA input is polarity and thermally protected.
Up to two CI drivers may be installed in an Aegis controller in addition to the fixed 4-20mA input at controller
i
nput‘ G’.

Card Installation
1. Turn OFF the controller AC power
2. CI driver car
dsmaybei nstalledi
nei t
hert heSensor s‘C’&‘ D’orSensor s‘E’ &‘F’sl ot
.
3. Turn ON the controller after installing the CI Driver and the controller will auto-configure, displaying both
inputs as millivolt levels, 200mV=4mA to 1000mV=20mA.

Driver Wiring

LoopPowe re d
Se nsor
- +
Cur re nt Loop Inputs
m ay be any com bination
or pow e re d and
loop pow e re d

1+ 2+ 15 VDC
Part: CI

- + Controlle r DCSupply
4-20mAOutput
15 to 22 V DC Supply
The rm ally fus e d at
Powered Loop 4-20mA 100 m A
Curre ntLoop
DualInput

Gre e n light tur ns

ON w he n loop
curr e nt gr e ate r
Loop 1 Loop 2 than 3.5 m A
>3.5 mA >3.5 mA

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 AEGIS Technical Manual

7.4.1 Installation cont.

Driver Wiring

AWG22 / 0.25 mm2, current loop cabling may be extended several hundred feet or meters without causing
measurement errors. The maximum cable length is determined by the open loop voltage and the cable gauge.

Do not install current loop cabling in the same conduit as AC power cabling.

Current loop cabling may share a common conduit with other sensors, water meter and contact set cabling.

7.4.2 Configuration - Operation

Diagnostics

Parameter LCD Browser Value : Use

Display
Sensor Location OK C: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK 4-20mA Input: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 1836 gpm: Current measured conductivity, display user set
units,‘---’def ault.Di spl
ayedwi thusersetr esoluti
on
Period Maximum OK 1920 gpm: Data from current log interval. Used to assess
controls.
Period Minimum OK 1110 gpm:
Period Average OK 1412 gpm:
Sample Size OK 1110: Samples in Period Max. Min. & Average
Current Period OK 46 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None / Rate-to-Volume:
Measured Level OK OK 787.5 mV: Raw sensor level in mV, before Gain & Offset after
ID Level correction.
Gain Multiplier OK OK 3.1250: Calibration adjusts Gain. Displayed Value = Measured
Level x Gain Multiplier + Offset Adjust
Default Gain OK OK 1.0000: Factory default Gain. Gain selected by Input Card ID
Offset Adjust OK OK -625: Offset. May be user adjusted.
Default Offset OK OK 0.0000: Factory default Offset. Offset selected by Input Card ID
Input Card ID OK OK 2218 mV: Design level = 2216mV.

Driver Verification Test:

Connect a 2K ohm (Optionally use 2 x 1K, 5%, 1/4W) resistor between controller +15 VDC terminal and CI
Driver terminal 1+.
Measured Level will be nominally 500mV if the +15VDC terminal is @ 20VDC.
Actual Level varies with the unregulated +15VDC supply and equals: 49.9 x ( VDC / (2000 + 49.9)) , where the
controller terminate the loop with 49.9 ohms and a 2,000 ohm test resistor is instlled.

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 AEGIS Technical Manual
7.4.2 Configuration - Operation cont.

Calibration
Currentloopswher e4mAi sNOTequalt oz
ero,GPM,uS… r
equi
ret
wopoi
ntcal
i
brat
iont
oconvert the
measured current into end user units.

The current loop may be calibrated using either the Keypad or the Browser, by either calculating the Offset &
Gain or driving the current loop between two values.

Two Point Calibration.

1. Configure the device or sensor controlling the current loop to operate at 4mA.
2. SelectSensor s/Cal ibrateand@ ‘ Enterfirstvalue’keyt he4mAl ev elinsi t
eunits.Forex ampl eifyour
current loop was spanned 0-2500GPM = 4-20mA, you would key 0 & Enter
3. Configure the device or sensor controlling the current loop to operate at 20mA.
4. Keyt he20mAl evel@ t he‘Ent ersecondVal ue’prompt .I nourex ampl ey ouwouldkey2500&Ent er
5. The controller will then calculate the Offset & Gain required to convert the measured current to user
units. In our 0-2500GPM example Gain = 3.125 & Offset = 625.

Any two loop currents may be used to calibrate. The previous 4mA & 20mA example is the optimum.
Accuracy improves as the difference between the two calibration currents increase.

Calculating Offset & Gain

1. The input Offset Adjust and Gain Multiplier may be manually set using Sensors / Configuration.
2. Thi smet hodt oconv ertameasur edcur rentt oauserv aluemaybeusedi fit
’snoteasyt odr iv
et he
current loop between 4 & 20 mA.

At 4mA the 50ohm loop terminating resistor measures 200mV ( 50 x 0.004).

At 20mA the 50ohm loop terminating resistor measures 1000mV ( 50 x 0.020).
As the current loop varies from 4-20mA, the controller measures a mV change from 200 to 1000; an
800mV change.

If the site 4mA_Level & 20mA_Level are known.

Gain Multiplier = ( 20mA_Level –4mA_Level ) / 800
Offset Adjust = -200 x Gain Multiplier

Example: 4mA_Level = 0 GPM & 20mA_Level = 2500 GPM

Gain Multiplier = 2500 /800 = 3.125
Offset Adjust = -200 x 3.125 = 625

Check: At4mAwe’
llmeasure200mVanddispl
ay200x3.125–625 = 0 GPM
At20mAwe’l
lmeasure1000mVanddispl
ay1000x3.125–625 = 2500 GPM

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7.4.3 Specifications

Function Notes
Resolution 0.0125% of span, 2uA Most current loop sources are 10 bit ,
resolution; typically 0.1% of span.
In this case, the source of the current
loop or loop powered sensor constrains
overall accuracy and resolution.
Accuracy +/- .05% of span
Max Input Voltage 30VDC Input is polarity protected to 50VDC and
thermally fused at 100mA.
Common, electrical ground inputs are
not fused.
Terminated Loop Green LED ON at loop Visual indication of correct loop wiring
Indicator currents greater than polarity and active loop power.
3.5mA

Notes:
1. Accuracy stated after calibration.
2. Resolution Example: If 4-20mA represents 0-2500GPM and the current transmitter has 10 bit
resolution, then flow rate would change in increments of 2.5 GPM.

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 AEGIS Technical Manual
7.5 IO: 4-20mA Output
Safety
30 VDC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.5.1 Installation

Services
The IO driver provides one or two, DC isolated, loop powered 4-20mA outputs.
Up to two dual, 4-20mAout put‘ I
O’driver smaybei ns t
all
edinanAegi scont r
oll er
.
The current output level 0% to 100% is logged by the controller.

Card Installation
1. Turn OFF the controller AC power
2. IO driver cardsmaybei nstal l
edi nei t
hert heSens or s‘C’&‘ D’orSensor s‘E’&‘ F’sl ot
.
3. Turn ON the controller after installing the IO Driver and the controller will auto-configure, displaying the
current output, on the LCD display and browser.

Current Loop Wiring

Distributed Remote Proportional

Control System Monitor Control
Loop Powered
4-20mA Input 4-20mA Input
Pump or Valve
+24V IN +24V IN - +

1+ 1- 2+ 2- 1+ 1- 2+ 2- 15 VDC
Part: IO Part: IO

Controller DC Supply

15 to 22 VDC Supply
Thermally fused at 100
mA
Single 4-20mA Dual 4-20mA
Output Output

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 AEGIS Technical Manual
7.5.1 Installation cont.

Current Loop Wiring

AWG22 / 0.25 mm2, current loop cabling may be extended several hundred feet or meters without causing
measurement errors. The maximum cable length is determined by the open loop voltage and the cable gauge.

Do not install current loop cabling in the same conduit as AC power cabling.

Current loop cabling may share a common conduit with other sensors, water meter and contact set cabling.

7.5.2 Configuration - Operation

Diagnostics

Parameter LCD Browser Value : Use

Display
Sensor Location OK Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK 4-20mA Output: verifies driver card type
Status OK OK Manual / Auto Loop open alarm
Displayed Value OK OK 12.0 mA & 50.0%:
Displays both current mA level & % of span
Displayed with user set resolution
Period Maximum OK 52.6% Data from current log interval. Used to assess controls.
Period Minimum OK 48.1%:
Period Average OK 50.2%:
Sample Size OK 48: Samples in Period Max. Min. & Average
Current Period OK 21 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Trim Span OK OK 950: 20mA span. Keypad adjustable
Trim Zero OK OK 9: 4mA zero. Keypad adjustable
Input Card ID OK OK 2467 mV: Design level = 2460mV.

Manual - Auto
A 4-20mA output may be switched from Auto control to Manual.
Manual mode allows the user to set an output from 0% to 100% to base feed, set up feed rates and verify
monitoring inputs.
On return to Auto the 4-20mA span and controlling sensor or relay are restored, unchanged.

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7.5.2 Configuration - Operation cont.

Hardware Calibration

DVM

DC Volts

V COM
4mA = 1V
Verifying Loop Current + - 20mA = 5V
1. Insert a mA meter in series with
current loop cabling.
OR
2. Test with loop disconnected
as shown on right Loop Terminating Resistor,
Typically 249 ohms

1+ 1- 2+ 2- 15 VDC
Part: IO

Controller DC Supply

Dual 4-20mA
Output

Hardware Calibration is used to compensate for component level errors.

I
t’
sonlyav ai
lablevi athekey padandf orcest hec ur
rentl
oopt o20mAt oadj
ustSPANandt
o4mAt
oadj
ust
ZERO. Trim Zero default = 9 Trim Span default = 950

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 AEGIS Technical Manual
7.5.3 Specifications

Function Notes
Resolution & Accuracy 0.1% & +/- 0.15%

DC Isolated Terminals 1+ & 1- DC Outputs DC isolated from electrical

isolated from 2+ & 2- ground –controller common.

Loop Polarity Auto-correcting Driver input terminals are not

sensitive to polarity.

Max Loop Voltage 30VDC. Current loops powered by the

controller unregulated 15VDC
supply do not exceed 24VDC.

Minimum Loop 10 ohms. LMI solenoid drive pump,

Termination proportional control input = 22
ohms

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 AEGIS Technical Manual
7.6 CR: Corrosion Rate
Safety
100mV DC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.6.1 Installation

Services
The CR driver measures one or two corrosion rates using Linear Polarization Resistance.
Dual CR drivers allow two alloys, copper & steel for example, to be monitored concurrently..
Uptot wodualandones ingl e‘CR’dr iv
er smaybei nstal
ledinanAegi sc ontr
oller
.

Card Installation
1. Turn OFF the controller AC power
2. The single and dual CR driver car dsmaybei nstall
edi nei t
hertheSensor s‘C’&‘ D’orSensor s‘E’ &‘ F’sl
ot .
3. Turn ON the controller after installing the CR Driver and the controller will auto-configure, displaying one or
both corrosion rates on the LCD display and browser.

Sensor Types
Aquatrac type CRS-SEN corrosion rate sensors.
Alloy sensor sets available in steel, copper, admiralty and cupro-nickel

Sensor Wiring

Sensor cabling is
not polarized

S1 S1 S2 S2 S1 S1 S2 S2

Part: OP

Dual Single
Sensor 2 Sensor 1 Corrosion Corrosion Sensor 1
Rate Rate
pH or ORP

Part: CR Part: CR

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7.6.1 Installation cont.

Sensor Wiring

Corrosion rate sensor cabling may be extended up to 200ft / 60m, using single pair AWG22 / 0.25 mm 2, cable
spliced to the sensor cable using wire nuts or crimped connectors located in an electrical fitting or enclosure.

Do not install sensor cabling in the same conduit as any AC power cabling.

Corrosion Rate sensor cabling may share a common conduit with other sensors, water meter and contact set
cabling.

7.6.2 Configuration - Operation

Setup-Calibration

Alloy Number:
The Alloy Number is used to convert the Linear Polarization Current to a rate of metal loss in mils/year.
The default Alloy Number is 1.000, Carbon Steel.
Common alloy numbers are Copper @ 2.00, 90/10 Cupro-Nickel @ 1.80, Zinc @ 1.29, Admiralty @ 1.67

Conductivity Sensor:
If the controller includes a conductivity sensor installed in the same sample stream at the corrosion rate
sensor, the corrosion rate measurement may be corrected for conductivity.
Conductivity correction has little effect at 1000uS with correction increasing as conductivity falls.
At low conductivities, LPR faults and alarms.

Calibration:
The CR driver can operate without calibration with nominally 0.05 mpy of static error caused by component
offsets in the driver card.
If you disconnect the sensor and calibrate for 0 mpy, the controller will correct the Offset for the static error.
This is a one-time calibration unless you move the CR driver to another controller slot. A new slot, resets the
offset calibration.

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7.6.2 Configuration - Operation cont.

Diagnostics

Parameter LCD Browser Value : Use

Display
Sensor Location OK E: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK Corrosion Rate: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 1.23 mpy: Current measured corrosion rate,
Displayed with user set resolution
Updates every 128 seconds
Period Maximum OK 1.28 mpy: Data from current log interval.
Period Minimum OK 1.21 mpy:
Period Average OK 1.22 mpy:
Sample Size OK 106: Samples in Period Max. Min. & Average
Current Period OK 26 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes
Compensation OK OK Corrosion Rate: Sequences through six steps,
repeating every 128 seconds
Anodic Level OK OK 52.1 mV: Anodic & Cathodic levels should be opposite in sign
and nominally the same value.
Cathodic Level OK OK -48.6 mV:
Pitting Level OK OK 1.2 mV: Pitting should always be less than either Anodic or
Cathodic. Pitting alarms are blocked for corrosion rates less
than 2mpy.
A Pitting level higher than the Anodic or Cathodic level is
an invalid corrosion rate measurement.
Replace pitted sensor tips.
Measured Level OK OK 6.8 mV: Raw sensor level in mV
Displayed in real time as the CR driver sequences.
Gain Multiplier OK OK 1.0000: User set Gain.
Default Gain OK OK 1.0000: Factory default Gain. Gain selected by Input Card ID
Offset Adjust OK OK -0.532: Offset.
Calibration adjusts Offset for hardware error.
Default Offset OK OK 0.0000: Factory default Offset.
Offset selected by Input Card ID
Input Card ID OK OK 1614 mV: Dual Design level = 1611mV.
Single Design level = 1548mV
Drive Level OK OK 1209.9 mV: Offset correction allied to measured values.
Inserted by driver card optical isolation.

Driver Verification Test:

Connect10Kohm r esi
storto‘S1’&‘ S1‘or‘
S2’&‘ S2’
.
Configure with Alloy Number =1.000 & no conductivity sensor.
Controller will display nominally 0.5mpy.
Anodic & Cathodic Levels will be nominally +/-50mV with pitting level +/-10mV.

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 AEGIS Technical Manual

7.6.3 Specifications

Function Notes
Resolution 0.1mpy Linear Polarization Resistance, LPR is applicable
where general corrosion is the dominant corrosion
mode.

LPR is useful in measuring relative corrosion

rates, process upsets and the immediate effect of
changing treatment programs or operating
conditions.

LPR is not an applicable technique for

processes where pitting is the dominant
corrosion mechanism.

Aluminum alloys and Stainless steels in cooling

water and waste water stream usually pit.

Sensor Drive DC Each sensor drive is separately electrically

Isolated. isolated from controller common and electrical
ground.

Uncalibrated Error 0.05 mpy Calibration with sensor disconnected removes

Nominal The effect of Uncalibrated Error

Notes:
1. Accuracy with respect to weight loss measurements is typically 50% to 200%.
2. The first valid corrosion rate measurement occurs 4 minutes after Power ON and is updated every
2 minutes thereafter.

CR Driver Revision Log

01/01/04 Initial release Version 037 CR Driver cards 16 Second measurement cycle
05/05/05 Version 054 CR Driver cards 128 Second measurement cycle
09/05/05 Rate with 10K test resistor now 0.5mpy Requires controller firmware
was 5mpy. Uncalibrated error reduced Version T095 and later.
from 0.5mpy to 0.05mpy
07/02/08 Reformatted for Aegis controllers

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 AEGIS Technical Manual
7.7 PT: pH - Temperature
Safety
+/-1VDC maximum on field wiring terminals.
24 VDC maximum on internal card surfaces.

7.7.1 Installation

Services
The PT, pH-Temperature driver measures a pH sensor and a temperature using a platinum RTD.

The driver can be jumper configured to measure either 100 ohm or 1000 ohm RTDs.
The controller detects the location of the RTD selection jumper on power up and auto-configures.

Upt
otwo‘ dr
PT’ i
ver
smaybei
nst
all
edi
nanAegi
scont
rol
l
er.

Although most installations will use the PT driver temperature input to thermally compensate the pH input, the
pH and temperature inputs of the PT driver may be also used independently to control pumps and solenoids.

Temperature Compensation of pH
Cooling Tower Applications
The amount of pH variation with temperature increases as the pH increases above pH 7 or decreases
below pH 7. Cooling towers operating around pH 8 and over a narrow temperature range are seldom
temperature compensated. The pH error due to temperature in cooling towers is nominally 0.1pH which
does not justify the cost and complexity of pH temperature compensation.
Process Applications
Temperature changes the mV/pH response of the pH sensor. The following table shows how the response
of the pH sensor varies with temperature and the error that temperature compensation of pH corrects.

The 8pH column is included to demonstrate the minimal effect temperature has in the 50-90F
typical cooling tower application range.

Temperature millivolts/pH mV@ 4pH mV @ 7pH mV @ 8pH mV @ 10pH

pH error pH error pH error pH error

0C or 32F -54.2 162.6mV 0mV -54.2mV -162.6mV

0.25pH 0pH 0.08pH 0.25pH

25C or 77F -59.16 177.5mV 0mV -59.2mV -177.5mV

100C or 212F -74.04 222.12 0mV -74.04mV -222.12

0.79pH 0pH 0.25pH 0.79pH

The mV/pH value is the controller pH sensor GAIN.

Thecontrol
ler’
sdef aultpHsensor25CGAIN is 0.017, nominally 1 / 59.16 mV/pH

When the pH sensor Compensation is set to Temperature, the controller adjusts the pH sensor GAIN
based on the value measured at the selected Temperature sensor.

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7.7.1 Installation cont.

Controller Services
The controller provides services to calibrate the RTD temperature and to warn you of wiring & operational
problems. The controller limits the range of temperatures that can be used for pH temperature
compensation to limit operating problems on a defective or mis-calibrated RTD sensor.

1. Temperature compensation of pH can only be applied to pH sensors connected to pH input cards.

4-20mA inputs representing pH cannot be thermally compensated since these sensors are usually
compensated at the pH to 4-20mA converter.

2. Compensating temperatures are only applied in the range of 0-100C, 0-212F. Out of range
temperatures are not used for compensation. No thermal compensation of pH occurs.
Set the HIGH & LOW alarms on the compensating thermal sensor to detect this fault.

3. Any temperature sensor, including the RTD sensor connected to the PT Driver card may be used to
temperature compensate a pH sensor.

4. RTD calibration is limited to +/-20 degrees before a calibration error occurs. The warning may be
overridden by the user.

5. The default RTD is 0.00385 ohm/ohm/C where the default GAIN = 1/0.00385 = 259.74. If you are using
and RTD with a response other than 0.00385, use SENSOR / CONFIGURE to set the correct GAIN.

6. Disconnected RDT sensors will display –50C or –50F. When the controller measures an RTD voltage
of less than 1000mV, it sets the RTD temperature to –50C or -50F.

7. When you select SYSTEM / CONFIGURE / Metric Units, the controller displays RTD temperatures in
degrees C independent of the user set units for temperature.

8. Temperature compensation of a pH sensor can also be configured and monitored using the keypad
and controller LCD display

Card Installation
1. Turn OFF the controller AC power
2. PT dr i
vercar dsmaybei nstall
edi nei thert heSensor s‘C’&‘ D’orSensor s‘E’&‘ F’sl ot.
3. Connect the pH and RTD sensors to the driver field wiring terminals.
4. Set the PT driver jumper to match the pH sensor RTD value, either 100 ohms or 1000 ohms. If you
don’ tknowt heRTDv alue,measur et her esi
stancebet weent het woAWG24sensort emper aturewi res.
5. Turn ON the controller after installing the PT Driver and the controller will auto-configure, displaying the
installed sensor or sensors on the LCD display and browser.

Sensor Part Numbers

Aquatrac immersion rated pH sensor part numbers A261107, A261108 and A261109 include
a thermal compensation RTD,
Generally, any pH sensor with a single coaxial cable and a 2 wire 100 ohm or 1000 ohm RTD may be used
with the PT drivers.

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 AEGIS Technical Manual
7.7.1 Installation cont.

Sensor Wiring

Connect the Coaxial cable

wir
est o‘pH’&t he
AWG24wi rest
o‘ Temp’

pH+ pH- Temp pH+ pH- Temp

Center Shield + Center Shield +
Immersion
Rated
Part: PT Part: PT
pH Sensor
& RTD pH Sensor
& RTD
Immersion pH sensors
usally do not require a Sensor, Entry &
solution ground since pH & pH & Solution Ground
both the vessel and the Temperature Temperature
controller are grounded. pH sensors installed
in plastic piping
usually require a
solution ground.
pH pH
1K Temp 1K Temp
100R ID 100R ID
RTD Common RTD Common

Att emper atur

esbel ow75F/25C,hi gherint
ernal pHi mpedancel i
mi tsapHsensor’
s
cabling to nominally 25ft or 10m.
At temperatures above 100F /40C in conductive process streams, pH sensor cabling
may be extended to typically 50ft, 20m without using a sensor amplifier.

Do not install pH sensor cabling in the same conduit as AC power cabling.

pH sensor cabling may share a common conduit with other sensors, water meter and contact set cabling.
Solution grounds are single conductor AWG18-22 / 0.25-0.75 mm2.

Warning:
Turn OFF the controller before connecting or disconnecting pH sensors & selecting RTD.

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 AEGIS Technical Manual
7.7.2 Configuration - Operation

RTD Selection
Changing the Selected RTD Set:
Turn controller OFF before changing the RTD selection jumper.
Controllers check the RTD selection jumper on power up, auto-configuring the temperature measurement.

pH+ pH- Temp

Center Shield +

Part: PT

pH &
Temperature

pH
1K Temp
100R ID
RTD Common

Jumper 1K
for 1000 ohm
RTD

Jumper 100R
for 100 ohm
RTD

Driver Test Header

DVM
pH = +/- 200mV, Sensor millivolts
Temp = 3000 to 4000mV
millivolts
RTD current + RTD drive
Com V
ID = Card ID Level, 1850mV
- +

pH
Temp
ID
Common

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 AEGIS Technical Manual

7.7.3 Diagnostics pH Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK A: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK pH Sensor: verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 8.12pH:Cur rentmeasur edpH,di spl ayusersetuni ts,‘
pH’
default. Displayed with user set resolution
Period Maximum OK 8.15 pH: Data from current log interval. Used to assess controls.
Period Minimum OK 8.05 pH:
Period Average OK 8.10 pH:
Sample Size OK 122: Samples in Period Max. Min. & Average
Current Period OK 18 minutes: Elapsed time in current log period
Log Period OK 15 minutes: User set log period 5 to 1440 minutes
Compensation OK OK None or Thermal Compen.
Measured Level OK OK 62.3 mV: Raw sensor level in mV, before Gain & Offset after ID
Level correction.
Gain Multiplier OK OK 0.0170: User set Gain
Default Gain OK OK 0.0170: Factory default Gain, 59mV/pH
Gain selected by Input Card ID
Offset Adjust OK OK 7.2361: Offset. Calibration adjusts Offset.
Displayed Value = Measured Level x Gain Multiplier + Offset
Adjust
Default Offset OK OK 7.0000: Factory default Offset. Offset selected by Input Card ID
Input Card ID OK OK 1854 mV: PT driver Design level = 1850 mV.
Note: The ID level identifies this pH input as a PT driver.
pH-ORP driver only cards have lower Input Card IDs

Sensor Default Gain Calibration Default Offset

Type Offset Span
PH 0.017 6 –8 7

Calibration: A calculated offset outside of the Calibration Offset Span

requires a user selected Override to complete calibration.

Driver Verification Test:

Connect a pH sensor, center conductor to pH+ and shield to pH-. Immerse sensor into pH10 buffer and
connect a solution ground wire with an exposed wire end immersed in the buffer.
Measured Level = +170mV +/-25mV

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 AEGIS Technical Manual
7.7.3 Diagnostics: Temperature Input

Parameter LCD Browser Value : Use

Display
Sensor Location OK B: Installation slot. LCD displays slot letter on screen.
Input Card Type OK OK 100 ohm RTD OR 1000 ohm RTD : verifies driver card type
Current State OK OK Operational / Alarmed:
Displayed Value OK OK 128F:Cur r entmeasur edtemper atur e,di spl ayus ersetuni
t
s,‘
F’
OR‘ C”i f‘Met ric’sel ecteddefault.
Displayed with user set resolution
Period Maximum OK 132 F: Data from current log interval. Used to assess controls.
Period Minimum OK 126 F:
Period Average OK 129 F:
Sample Size OK 186: Samples in Period Max. Min. & Average
Current Period OK 38 minutes: Elapsed time in current log period
Log Period OK 60 minutes: User set log period 5 to 1440 minutes, Default 60
Compensation OK OK None. Note: Do not apply any type of Compensation to a
thermal sensor use to compensate a pH sensor
Measured Level OK OK 3126 mV: Raw sensor level in mV, before Gain & Offset after ID
Level correction.
Gain Multiplier OK OK 259.74: User set Gain. Do not change this value unless you
have changed the RTD type.
Default Gain OK OK 259.74: Factory default Gain,
= 1/ 0.00385 ohm / ohm /c
Offset Adjust OK OK -4.012: Offset. Calibration adjusts Offset.
Displayed Value = (Measured Level x Gain Multiplier & RTD to
temperature conversion) + Offset Adjust
Default Offset OK OK 0.0000: Factory default Offset.
Offset selected by Input Card ID
Input Card ID OK OK 100 ohm RTD = 43 mV RTD drive measurement level
1000 ohm RTD = 327 mV

Sensor Default Gain Calibration Default Offset

Type Offset Span
RTD 259.74 +20 to -20 0

Calibration: A calculated offset outside of the Calibration Offset Span

requires a user selected Override to complete calibration.

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 AEGIS Technical Manual

7.7.4 Specifications
Function Notes
Input Range 0-14 pH Defaults to 0.00385 ohm/ohm/C
100 ohm or 1000 ohm RTD, Resistive Thermal Device
Platinum RTD.

Resolution pH: 0.01 pH User controls pH and temperature

Temperature: 0.1C or displayed resolution from 0 to 3
0.05F digits after the decimal point.

Accuracy +/- 0.05F/C Requires installed solution ground

+/- 0.02pH for non-immersion pH sensors.

pH Input Impedance > 500 MOhm Fully differential.

20M ohm power OFF input
resistance

Notes: Accuracy stated after sensor calibration.

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 AEGIS Technical Manual

Appendices
A: Revision Log

Issued Modifies/Adds Notes

07/03/08 Initial release Aegis_Tech.PDF on .ftp site

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 AEGIS Technical Manual

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