Table 35 — Illegal Configurations Recognized it reaches the top of its stroke (can be heard if

by PSIO-1 surroundings are relatively quiet). Press again if

CODE ILLEGAL CONFIGURATION necessary to confirm this. Press four times to step
NUMBER DESCRIPTION
the actuator closed in 25% increments, waiting again in be-
Incorrect Check Sum in configuration code tween each move. The actuator should knock when it reaches
1 (factory or service code)
the bottom of its stroke. If it is believed that the valve is not
2 Unit type outside range of (1-3)
working properly, continue with the checkout procedure
Number of compressors in a circuit outside the below:
3 range of 0-2
Air cooled chiller with a fan type outside the Check the EXV output signals at appropriate terminals
4 range of 1-16 on EXV driver module (see Fig. 12). Connect positive test
Air cooled chiller with Low Temperature Brine lead to terminal 1 on the EXV driver for Circuit A and to
5 fluid terminal 7 for Circuit B. Set meter for approximately 20 vdc.
6
Water cooled chiller configured for air cooled Enter Valves and Motor Master test subfunction by pressing
head pressure on the HSIO. The EXV for Circuit A will be dis-
Selecting both OAT and Space Temp sensors
7 for External Reset operation played; if desired, press the down arrow key for Circuit B.
8 Air cooled chiller with condenser water pump When at the desired valve, press . The display should
9 Air cooled chiller with condenser thermistors
change to show a Target Percent of 25%. The driver should
MOP Set point is outside the range of
10
40 - 55 F (4.4 - 12.8 C) drive the circuit EXV under test. During the next several sec-
Maximum Condensing Temperature Set point
onds, connect negative test lead to pins 2, 3, 4, and 5 in suc-
11 (MCT_SP) is outside the range of 0 - 158 F cession (pins 8, 9, 10 and 11 for Circuit B). Voltage should
(-17.8 - 70 C) rise and fall at each pin. If it remains constant at a voltage
LEGEND
or shows 0 volts, remove the connector to the valve and
recheck.
MOP — Minimum Operating Temperature
OAT — Outdoor-Air Temperature Press to close the circuit EXV. Check the DSIO
address setting (the address should be 50). If a problem still
EXD Troubleshooting Procedure — Follow steps exists, replace the EXV driver module. If the voltage read-
below to diagnose and correct EXV/Economizer problems. ing is correct, the expansion valve and EXV wiring should
On 30HX units with economizers, verify that the valve be checked. Check the EXV terminal strip and interconnect-
for the bubbler tube (bottom of economizer) is open. Check ing wiring.
EXV motor operation first. Press on the HSIO II 1. Check color coding and wire connections. Make sure they
keypad and select the appropriate EXV. Press to are connected to the correct terminals at the EXV driver
and EXV plug and that the cables are not crossed.
move the valve to 25%. You should be able to feel the ac-
tuator moving by placing your hand on the EXV or econo- 2. Check for continuity and tight connection at all pin
mizer body (the actuator is located about one-half to two- terminals.
thirds of the way up from the bottom of the economizer shell). Check the resistance of the EXV motor windings.
Press three more times until the display reads 100% Remove the DSIO-EXV plug J4 terminal strip and check the
resistance between the common lead (red wire, terminal D)
for a Target Percent (waiting until actuator stops each time). and remaining leads, A, B, C, and E (see Fig. 12). The re-
A hard knocking should be felt from the actuator when sistance should be 25 ohms ± 2 ohms.

EXV — Electronic Expansion

Valve

Fig. 12 — EXV Cable Connections to EXV Driver Module, DSIO-EXV

50
INSPECTING/OPENING ELECTRONIC EXPANSION 2. Remove any remaining refrigerant from the system low
VALVES side and discharge piping using proper reclaiming tech-
niques. For 30GX units, there is no shutoff valve in the
IMPORTANT: Obtain replacement O-ring before open- bubbler tube line. Drain oil from cooler using Schrader
ing EXV. Do not reuse O-rings. port in cooler inlet line. Turn off the line voltage power
supply to the compressors and control circuit power.
To check the physical operation of an EXV, the following 3. Remove the shell retaining bolts on the bottom of the econo-
steps must be performed: mizer and the bolts that secure the shell to the unit frame
1. Close the liquid line service valve of the circuit to be checked. or mounting bracket. Cut the motor cooling line leaving
Put the LOR switch in the OFF position. Using the the top of the economizer. Carefully remove the shell from
HSIO, enter the manual service mode by pressing the economizer. Make sure EXV plug is still connected.
. Enable the mode by pressing . Switch
IMPORTANT: When removing shell from econo-
the LOR switch to the Local position. Scroll down to the mizer, it must be lifted off as close to vertical as
desired compressor and press to turn it on. Let possible to prevent damage to any of the internal
compressor run until gage on suction pressure port reads parts. Use a catch pan beneath the economizer as
oil will come out when the shell is removed. Be
between 5 and 10 psig. Press to turn the com- careful to avoid damage to motor leads.
pressor off. Immediately after the compressor shuts off,
close the discharge valve.
4. Enter the appropriate EXV test step for EXV-A or EXV-B
2. Remove any remaining refrigerant from the system low
side using proper reclaiming techniques. Drain oil from by pressing on the HSIO. Scroll down to display
cooler using Schrader port in cooler inlet line. Turn off the desired EXV. Press and to initiate the test.
the line voltage power supply to the compressors and con- Observe the operation of the valve motor and lead screw.
trol circuit power. The motor should turn counterclockwise, and the lead screw
3. Remove screws holding top cover of EXV. Carefully re- should move up out of the motor hub until the valve is
move the top cover from the EXV making sure EXV plug fully open. Lead screw movement should be smooth and
is still connected. uniform from fully closed to fully open position. Press
as needed to reach 100% open. Wait 30 seconds
IMPORTANT: When removing top cover from
EXVs, be careful to avoid damage to motor leads. in between each step for motor to stop moving. Press
to check open to closed operation. If the valve is
4. Enter the appropriate EXV test step for EXV-A or EXV-B properly connected to the processor and receiving correct
signals, yet does not operate as described above, the econo-
by pressing on the HSIO. Scroll down to display mizer should be replaced.
the desired EXV. Press and to initiate the test. 5. Additional items to check for:
Observe the operation of the valve motor and lead screw. a. Verify that float assembly (see cross section view in
The motor should turn counterclockwise, and the lead screw Fig. 13) moves up and down freely. It should take only
should move up out of the motor hub until the valve is a minimal force (less than one pound) to move the float
fully open. Lead screw movement should be smooth and and there should be no binding.
uniform from fully closed to fully open position. Press
b. Check the bubbler tube (found by carefully lifting the
as needed to reach 100% open. Wait 30 seconds float) for crimps, etc. and verify that the end of the
in between each step for motor to stop moving. Press tube is open.
to check open to closed operation. If the valve is 6. Reassemble economizer; retorque shell retaining bolts to
35 ft-lb (48 N-m).
properly connected to the processor and receiving correct
signals, yet does not operate as described above, the valve If operating problems persist after reassembly, they may
should be replaced. be due to a bad liquid level sensor, suction pressure trans-
ducer or intermittent connections between the processor board
terminals and EXV plug. Recheck all wiring connections and
INSPECTING/OPENING ECONOMIZERS — To check the voltage signals.
physical operation of an economizer (see Fig. 13), the fol-
lowing steps must be performed: Other possible causes of improper refrigerant flow con-
trol could be restrictions in the liquid line. Check for plugged
1. Close the liquid line service valve of the circuit to be checked. strainer(s) or restricted metering slots in the EXV or econo-
Put the LOR switch in the OFF position. Using the mizer. Formation of ice or frost on lower body of electronic
HSIO, enter the manual service mode by pressing expansion valve is one symptom of restricted metering slots.
. Enable the mode by pressing . Switch However, frost or ice formation is normally expected when
the LOR switch to the Local position. Scroll down to the leaving fluid temperature from the cooler is below 40 F. Clean
desired compressor and press to turn it on. Let or replace valve if necessary.
compressor run until gage on suction pressure port reads NOTE (non-economizer units only): Frosting of valve is nor-
between 5 and 10 psig. Press to turn the com- mal during compressor test steps and at initial start-up. Frost
should dissipate after 5 to 10 minutes operation in a system
pressor off. Immediately after the compressor shuts off, that is operating properly. If valve is to be replaced, wrap
close the discharge valve and the bubbler valve on 30HX valve with a wet cloth to prevent excessive heat from dam-
units (located in elbow fitting on condenser shell). aging internal components.

51
 Fig. 13 — 30GX,HX Cutaway View of
Economizer Assembly

SERVICE
Servicing Coolers and Condensers — When cooler Fig. 14 — Tube Plugging
heads and partition plates are removed, tube sheets are ex-
posed showing the ends of tubes. The 30GX,HX units use a
flooded cooler design. Water flows inside the tubes. Table 36 — Plugging Components
TUBE PLUGGING — A leaky tube can be plugged until
COMPONENTS FOR PLUGGING PART NUMBER
retubing can be done. The number of tubes plugged deter-
mines how soon the cooler must be retubed. All tubes in the For Tubes
Brass Pin 853103-1A*
30GX and 30HX coolers and 30HX condensers can be re- Brass Ring 853002-640*
moved. Loss of unit capacity and efficiency as well as in- For Holes without Tubes
creased pump power will result from plugging tubes. Failed Brass Pin 853103-1A*
tubes should be replaced as soon as possible. Up to 10% of Brass Ring 853002-738*
the total number of tubes can be plugged before retubing is Roller Extension S82-112/11
necessary. Figure 14 shows an Elliot tube plug and a cross- Loctite No. 675†
sectional view of a plug in place. The same components for Locquic ‘‘N’’†
plugging and rolling tubes can be used for all coolers and *Order directly from: Elliot Tube Company, Dayton, Ohio.
30HXC condensers. See Table 36. †Can be obtained locally.

Table 37 — Tube Diameters

Use extreme care when installing plugs to prevent dam- ITEM INCHES MILLIMETERS
age to the tube sheet section between the holes. Tube sheet hole diameter: 0.756 19.20
Tube OD 0.750 19.05
Tube ID after rolling: 0.704 17.88
RETUBING (See Table 37) — When retubing is to be done, (includes expansion to to
obtain service of qualified personnel experienced in boiler due to clearance) 0.710 18.03
maintenance and repair. Most standard procedures can be fol- NOTE: Tubes replaced along heat exchanger head partitions must
lowed when retubing the 30GX and 30HX heat exchangers. be flush with tube sheet.
A 7% crush is recommended when rolling replacement tubes TIGHTENING COOLER/CONDENSER HEAD BOLTS
into the tubesheet. A 7% crush can be achieved by setting
the torque on the gun at 48 to 50 in.-lb (5.4 to 5.6 N-m). O-Ring Preparation — When reassembling cooler and con-
The following Elliot Co. tube rolling tools are required: denser heads, always check the condition of the O-ring(s)
first. The O-ring should be replaced if there are any visible
B3400 Expander Assembly B3405 Mandrel signs of deterioration, cuts or damage. Apply a thin film of
B3401 Cage B3408 Rolls grease to the O-ring before installation. This will aid in hold-
Place one drop of Loctite No. 675 or equivalent on top of ing the O-ring into the groove while the head is installed.
tube prior to rolling. This material is intended to ‘‘wick’’ into Torque all bolts to the following specification and in the
the area of the tube that is not rolled into the tube sheet, and sequence shown in Fig. 15.
3Ú4-in. Diameter Perimeter and
prevent fluid from accumulating between the tube and the
tube sheet. New tubes must also be rolled into the center Plate Bolts . . . . . . . . . . . . . . . . . . . . . . . . 200 to 225 ft-lb.
tube sheet to prevent circuit-to-circuit refrigerant leakage. (271 to 305 N-m)

52
 Fig. 15 — Cooler and Condenser Head Recommended Bolt Torque Sequence

1. Install all bolts finger tight. may be dirty, or water flow may be incorrect. Due to the
2. Follow numbered sequence shown for head type being pressure in the R-134a system, air usually will not enter the
installed. This will apply even pressure to the O-ring. machine; the refrigerant will leak out.
3. Apply torque in one-third steps until required torque is During the tube cleaning process, use brushes specially
reached. Load all bolts to each one-third step before pro- designed to avoid scraping and scratching the tube wall. Con-
ceeding to the next one-third step. tact your Carrier representative to obtain these brushes. Do
not use wire brushes.
4. No less than one hour later, retighten all bolts to required
torque values.
5. Restore water/brine flow and check for leaks. Fix leaks
as necessary. Replace insulation (on cooler heads only). Hard scale may require chemical treatment for its pre-
vention or removal. Consult a water treatment specialist
Inspecting/Cleaning Heat Exchangers for proper treatment procedures.
COOLERS — Inspect and clean the cooler tubes at the end
of the first operating season. Because these tubes have in- Water Treatment — Untreated or improperly treated
ternal ridges, a rotary-type tube cleaning system is neces- water may result in corrosion, scaling, erosion, or algae. The
sary to fully clean the tubes. Tube condition in the cooler services of a qualified water treatment specialist should be
will determine the scheduled frequency for cleaning, and will obtained to develop and monitor a treatment program.
indicate whether water treatment is adequate in the chilled
water/brine circuit. Inspect the entering and leaving ther-
mistors for signs of corrosion or scale. Replace the sensor if Water must be within design flow limits, clean and treated
corroded or remove any scale if found. to ensure proper machine performance and reduce the
CONDENSERS (30HX Only) — Since this water circuit is potential of tubing damage due to corrosion, scaling, ero-
usually an open-type system, the tubes may be subject to sion, and algae. Carrier assumes no responsibility for
contamination and scale. Clean the condenser tubes with a chiller or condenser damage resulting from untreated or
rotary tube cleaning system at regular intervals, and more improperly treated water.
often if the water is contaminated. Inspect the entering and
leaving condenser water thermistors (if installed) for signs
of corrosion or scale. Replace the sensor if corroded or re- Condenser Coils (30GX Only)
move any scale if found. COIL CLEANING — Clean coils with a vacuum cleaner,
Higher than normal condenser pressures, together with in- fresh water, compressed air, or a bristle brush (not wire). Units
ability to reach full refrigeration load, usually indicate dirty installed in corrosive environments should have coil clean-
tubes or air in the machine. If the refrigeration log indicates ing as part of a planned maintenance schedule. In this type
a rise above normal condenser pressures, check the con- of application, all accumulations of dirt should be cleaned
denser refrigerant temperature against the leaving condenser off the coil.
water temperature. If this reading is more than what the de-
sign difference is supposed to be, then the condenser tubes
53
 Do not use high-pressure water or air to clean coils as
fin damage may result.

Condenser Fans (30GX Only) — Each fan is sup-

ported by a formed wire mount bolted to a fan deck and
covered with a wire guard. The exposed end of the fan
motor shaft is protected from weather by grease. If the fan
motor must be removed for service or replacement, be sure
to regrease fan shaft and reinstall fan cover, retaining clips,
and fan guard. For proper performance, the fans should be
positioned as shown in Fig. 16 or 17. Tighten setscrews to
14 ± 1 ft-lb (18 ± 1.3 N-m).
Fig. 16 — Condenser Fan Position (Standard Fan)
Check for proper rotation of the fan(s) once reinstalled
(clockwise for high static and counterclockwise for standard
viewed from above). If necessary to reverse, switch leads at
contactor(s) in control box.

Refrigerant Charging/Adding Charge

IMPORTANT: These units are designed for use with
R-134a only. DO NOT USE ANY OTHER REFRIG-
ERANT in these units without first consulting your
Carrier representative.

Fig. 17 — Condenser Fan Position (High Static Fan)

When adding or removing charge, circulate water through
the condenser (30HXC) and cooler at all times to pre-
vent freezing. Freezing damage is considered abuse and 5. If the refrigerant appears to be flashing, the circuit is prob-
may void the Carrier warranty. ably low on charge. Verify this by checking the EXV
Percent Open. This information can be accessed by
entering on the HSIO keypad for Circuit A, or
for Circuit B. Scroll down using the down arrow
DO NOT OVERCHARGE system. Overcharging re- key on the keypad, until EXV Percent Open is displayed.
sults in higher discharge pressure with higher cooling
fluid consumption, possible compressor damage and higher 6. If the EXV Percent Open is greater than 60%, and the
power consumption. liquid-line sight glass is flashing, then the circuit is low
on charge. Follow the procedure for adding charge for
Indication of low charge on a 30HXC system: 30HXC units.
NOTE: To check for low refrigerant charge on a 30HXC, To add charge to the 30HXC systems:
several factors must be considered. A flashing liquid-line sight 1. Make sure that the unit is running at full load, and that
glass is not necessarily an indication of inadequate charge. the cooler leaving fluid temperature is in the range of 42
There are many system conditions where a flashing sight glass to 46 F (5.6 to 7.8 C).
occurs under normal operation. The 30HXC metering de- 2. At these operating conditions, check the liquid line sight
vice is designed to work properly under these conditions. glass. If there is a clear sight glass, then the unit has suf-
1. Make sure that the circuit is running at a full-load con- ficient charge. If the sight glass is flashing, then check the
dition. To check whether circuit A is fully loaded, enter EXV Percent Open. If this is greater than 60%, then be-
on the HSIO keypad. The display will read gin adding charge.
‘‘CIRCUIT A ANALOG VALUES.’’ Using the down ar- NOTE: A flashing liquid line sight glass at operating con-
row key on the keypad, scroll down once to ‘‘Total ditions other than those mentioned above is not neces-
Capacity.’’ If this value is 100%, the circuit is at full load. sarily an indication of low refrigerant charge.
To check circuit B, follow the same procedure, but enter 3. Add 5 lb of liquid charge into the cooler using the 1Ú4-in.
on the keypad. Schrader-type fitting located on the tube entering the bot-
tom of the cooler. This fitting is located between the Elec-
2. It may be necessary to use the Manual Control feature to tronic Expansion Valve (EXV) (size 076-146 units), or
force the circuit into a full-load condition. If this is the the economizer (size 161-271 units) and the cooler.
case, see the instructions for using the Manual Control
feature in Table 19 of this manual. 4. Observe the EXV Percent Open value. The EXV should
begin closing as charge is being added. Allow the unit to
3. With the circuit running at full load, verify that the cooler stabilize. If the EXV Percent Open remains above 60%,
leaving fluid temperature is in the range of 38 to 46 F and the sight glass continues flashing, add an additional
(3.3 to 7.8 C). Check pressure drop across liquid line strainer 5 lb of liquid charge.
and replace strainer if necessary.
5. Allow the unit to stabilize, and again check the EXV Per-
4. At this condition, observe the refrigerant in the liquid line cent Open. Continue adding 5 lb at a time of liquid re-
sight glass. If there is a clear sight glass, and no signs of frigerant charge, and allow the unit to stabilize before
flashing, then the circuit is adequately charged. Skip the checking the EXV position.
remaining steps.
54
6. When the EXV Percent Open is in the range of 40 to 60%, 3. After running the unit for 11Ú2 hours, allow the unit to
check the liquid line sight glass. Slowly add enough ad- restart and run normally. If the Low Oil Level alarms
ditional liquid charge to ensure a clear sight glass. This persist, continue following this procedure.
should be done slowly to avoid over-charging the unit. 4. Close the liquid line service valve, and place a pressure
7. Verify adequate charge by continuing to run at full load gage on top of the cooler. Enable the manual control
with 42 to 46 F (5.6 to 7.8 C) cooler leaving fluid tem- feature using the HSIO keypad, and turn the LOR switch
perature. Check that the refrigerant is not flashing in the to local. Start the desired compressor by pressing
liquid-line sight glass. The EXV Percent Open should be on the keypad, at the appropriate line on the
between 40 and 60%. The cooler level indicator should
be in the range of 1.5 to 2.2. display.
Indication of low charge on a 30HXA, GX systems: 5. Before starting the compressor, the unit will go through
its normal pre-lube pump routine. If there is an insuf-
1. Make sure that the circuit is running at a full load con- ficient level of oil in the oil separator, the compressor
dition and all condenser fans are energized and running will not start, and a pre-start oil pressure alarm will be
at full speed. To check whether circuit A is fully loaded, posted. Skip to Step 8.
enter on the HSIO keypad. The display will read 6. If the compressor starts successfully, observe the cooler
‘‘CIRCUIT A ANALOG VALUES.’’ Using the down ar- pressure gage. When this gage reads approximately
row key on the keypad, scroll down once to ‘‘Total 10 psig, press on the HSIO keypad, and move
Capacity.’’ If this value is 100%, the circuit is at full load.
To check circuit B, follow the same procedure, but enter the LOR switch to the off position.
on the keypad. 7. Open the liquid line service valve and allow the unit to
restart and run normally. If the Low Oil Level alarms
2. It may be necessary to use the Manual Control feature to persist, continue following this procedure.
force the circuit into a full-load condition. If this is the
case, see the instructions for using the Manual Control 8. If none of the previous steps were successful, the unit is
feature in Table 19 on page 31 of this manual. low on oil charge. Add oil to the oil separator using the
1Ú4-in. Schrader-type fitting on the discharge line enter-
3. With the circuit running at full-load, verify that the cooler ing the top of the oil separator (30HX units) or through
leaving fluid temperature is in the range of 38 to 48 F the Schrader fitting on the top of the oil separator (30GX
(5.6 to 7.8 C). units).
4. For 30HXA chillers, raise the compressor discharge to
approximately 125 F (51.7 C) saturated discharge tem-
perature (185 psig [1276 kPa]). For 30GX chillers, raise
the compressor discharge to approximately 130 F Do not add oil at any other location as improper
(54.4 C) saturated discharge temperature (198 psig unit operation may result.
[1366 kPa]). Measure the liquid temperature entering the 9. Make sure that the unit is not running when adding oil,
expansion device for 30HXA units. For 30GX units, mea- as this will make the oil charging process easier. Be-
sure the liquid temperature after the tee where all liquid cause the system is under pressure even when the unit
lines have joined. The liquid temperature should be ap- is not running, it will be necessary to use a suitable pump
proximately 107 F (41.7 C) for optimum charge. If the (hand pump or electric pump) to add oil to the system.
temperature is greater than 107 F (41.7 C) and the sight
glass is flashing, the circuit is undercharged. 10. Using a suitable pump, add 1Ú2 gal. (1.89 L) of Castrol
Icematic SW-220 Polyolester oil (Carrier Specifica-
5. Add 5 lb of liquid charge into the cooler using the 1Ú4-in. tion number is PP47-32; absolutely no substitutes are
Schrader-type fitting located on the tube entering the bot- approved) to the system. Make sure that the oil level
tom of the cooler. This fitting is located between the Elec- safety switch is NOT jumpered, and allow the unit to
tronic Expansion Valve (EXV) (30HXA076-146 units, restart and run normally. Do not exceed maximum oil
30GX080-090 units), or the economizer (30HXA161- change. See Table 38.
271 units, 30GX105-176 units) and the cooler.
11. If low oil level problems persist, add another 1.89 L
6. Allow the system to stabilize and then recheck the liquid (1Ú2 gal.) of oil. Continue adding oil in 1.89 L (1Ú2 gal.)
temperature. Repeat Step 5 as needed allowing the sys- increments until the problem is resolved. If it is neces-
tem to stabilize between each charge addition. Slowly add sary to add more than 5.75 L (1.5 gallons) of oil to the
charge as the sight glass begins to clear to avoid system, contact your Carrier distributor service
overcharging. department.
Oil Charging/Low Oil Recharging Table 38 — Maximum Oil Charges
Addition of oil charge to 30HX,GX systems:
UNIT CIRCUIT A CIRCUIT A CIRCUIT B CIRCUIT B
1. If the 30HX,GX unit shuts off repeatedly on Low Oil SIZE (gal) (L) (gal) (L)
Level (Alert number 71 or 72), this may be an indica- 30GX080-176 5.0 18.9 5.0 18.9
tion of inadequate oil charge. It could also mean simply 30GX205-265 7.0 26.5 5.0 18.9
that oil is in the process of being reclaimed from the 30HXA076-186 5.0 18.9 5.0 18.9
low-side of the system. 30HXC076-186 4.5 17.0 4.5 17.0
2. Begin by running the unit at full load for 11Ú2 hours. Use 30HXC206-271 7.5 28.4 5.0 18.9
the Manual Control feature of the software if the unit
does not normally run at full load.

55