ALTRONIC GAS ENGINE GOVERNOR OPERATING MANUAL

GOV10, GOV50 FORM GOV OM 10-02

WARNING: DEVIATION FROM THESE INSTALLATION INSTRUCTIONS MAY LEAD TO

IMPROPER ENGINE OPERATION WHICH COULD CAUSE PERSONAL INJURY TO
OPERATORS OR OTHER NEARBY PERSONNEL.

Version 5.02
November, 2002

ALTRONIC, INC.
712 Trumbull Ave.
Girard, Ohio 44420 USA

© Altronic, Inc. 2002

Form GOV OM 11-02.

Section 1

INTRODUCTION

1-1
Form GOV OM 11-02.

This manual provides instruction and maintenance information for the INTRODUCTION
GOV10/50. It is recommended that the user read this manual in its
entirety before commencing operations.

Do NOT attempt to operate, maintain, or repair the fuel control valve until
the contents of this document have been read and are thoroughly
understood.

Every attempt has been made to provide sufficient information in this

manual for the proper operation and maintenance of the GOV10/50.

If additional information is required, please contact:

Altronic, Inc.
712 Trumbull Ave.
Girard, OH 44420
(330) 545-9768

1-2
Form GOV OM 11-02.

The Altronic Gas Engine Governors are normally used with natural gas. WARNING
Natural gas and air, when combined together, become very combustible
and when contained within an enclosure, such as a fuel-injected
reciprocating engine or its exhaust system can explode in a violent
manner when ignited. It is necessary to always use extreme caution
when working with any fuel system. The control systems used with
natural gas fired, reciprocating engines should always be designed to be
“fail-safe”. Towards this goal, the GOV10/50 Gas Engine Governor plays
an important part in the safety of the whole system.

The GOV10/50 Gas Engine Governor is NOT a shutoff valve. Shutoff

valves should be used in addition to the Gas Engine Governor. The fuel
system should be designed in such a way that:

1. No single failure of a component will cause the fuel system to

admit fuel to the engine when the engine has been shutdown.
2. No single failure can result in grossly over-fueling the engine
when attempting to start.

Failure to follow the above rules may lead to possibly serious damage to
equipment or to personnel.

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Form GOV OM 11-02

Section 2
THEORY OF OPERATION

2-1
Form GOV OM 11-02

The GOV10/50 Gas Engine Governor is a gas engine governor designed THEORY OF
to be used as the speed control on fuel-injected reciprocating natural gas OPERATION
engines. The valve controls fuel flow by varying an orifice and uses fuel
gas pressure for actuation muscle. The valve consists of a tubular main
body, a poppet assembly, and an electronics component housing.
These three main sub-assemblies form a single integrated unit. The
GOV requires no separate actuators or mechanical linkage.

The main body contains an orifice plate (used for the optional flow
measurement feature) and the poppet assembly. Mounting flanges are
also bolted to the main body. The poppet assembly consists of the
following
• Poppet
• Poppet seat
• Oil-filled bellows section for dampening
• Return spring

The electronics housing contains

• Control gas pressure regulator
• Muscle gas controlling components
• Three (3) pressure transducers
• ∆P transducer
• Fuel temperature RTD
• 16-bit microprocessor board

The Governor Control Display Terminal accomplishes all necessary input

programming and data value read outs. The control module design
allows remote mounting at the operating or shutdown panel board of the
engine. RS-485 serial communications will allow up to 350 foot distance
for the remote terminal location.

Engine speed set point may be changed from the Display Terminal (part
no. TSA-100) or via a 4 to 20 mA signal input.

The GOV remains closed when the engine is not running. While in this
stopped mode, the GOV constantly monitors crankshaft speed. If the
crankshaft speed exceeds its programmed set point, the GOV assumes
that a start sequence is commencing, and begins its start up functions.

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Form GOV OM 11-02

When the crankshaft speed exceeds the above mentioned set point and
there is no fuel supply pressure available (the fuel block valve is closed),
the GOV assumes that the engine is purging and remains closed. The
engine purge time begins when the RPM exceeds the crank set point.

When the purge timer has expired and the supply pressure exceeds the
set point, the GOV begins controlling fuel manifold pressure for engine
starting. The fuel manifold pressure maintained for engine light off is
operator programmable. The GOV uses a separate dedicated PID control
loop to control fuel manifold pressure during starting.

After the engine fires off and achieves the programmable “IDLE SPEED”
(light-off speed) and a programmable warm-up timer expires, the GOV
uses a programmable rate internal ramp and increases fuel flow to the
engine until the minimum operating speed is achieved. When minimum
operating speed has been reached, the GOV begins to increase fuel flow
to the engine at the programmed ramp rate. When the engine speed set
point is reached, the GOV operates as an engine speed governor,
changing fuel flow as required to maintain the required speed set point.
The fuel flow will be increased until the engine speed set point has been
achieved. Thereafter, any time the speed set point is changed, the same
programmable ramp is used to accelerate or decelerate the engine. The
governor gains dynamically change based upon engine load. This feature
helps keep the engine speed as stable as possible, enhancing engine
performance and helping to keep exhaust emissions stable.

The GOV controls gas flow by changing the position of the poppet valve
very precisely. The poppet resides in a housing, which is O-ring mounted
inside the main valve body. The poppet stem is attached to a bellows.
Fuel gas pressure is admitted through a pressure regulator into the
control gas chamber. In the control gas chamber there are two small
nozzles. One of the nozzles is ported from the control gas chamber to the
enclosed side of the poppet bellowfram. The other nozzle is ported from
the control gas chamber to the down stream side of the poppet (into the
main fuel stream). One end of a small “paddle” moves between the two
nozzles.

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Form GOV OM 11-02

The paddle pivots on a small torsion bar so the paddle movement is

frictionless. On the opposite end of the paddle is a voice coil. The voice
coil is surrounded by a rare earth magnet. When the computer sends
voltage through the voice coil, it moves in the magnet, pivoting the paddle
as it moves. This causes the other end of the paddle to cover one nozzle
and uncover the other. As the nozzle ported downstream of the poppet is
covered, pressure builds in the control gas chamber and on the enclosed
side of the bellowfram, forcing the poppet in the open direction. As the
nozzle ported downstream is uncovered, pressure bleeds from the control
gas chamber and the bellowfram, letting the return spring force the poppet
in the closed direction.

The GOV10/50 contain several engine safety features. The features are SAFETY SHUTDOWNS
listed below:

NOSIGNAL – No magnetic pick-up signal. If the frequency input from

the magnetic pick-up drops below 35 Hz for more than 250 ms while the
engine is starting or running, the governor will close and remain closed
until the start sequence is re-initiated. The terminal controls display will
annunciate the message “NOSIGNAL”. This message will be displayed
until the engine achieves a full stop and the operator presses any button
on the governor interface or the engine is restarted.

LOWPRES – Low supply pressure. An alarm condition during starting or

running that if the upstream pressure drops below the governors
programmed “supply pressure setpoint”, the governor will close and
remain closed until the start sequence is re-initiated. The terminal control
display will annunciate the message “LOWPRES”. This message will
remain until the engine reaches a complete stop and the operator presses
any button the governor interface or the engine is restarted.

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Form GOV OM 11-02

OVRSPEED – Engine overspeed. This is an operator adjustable

setpoint for the shutdown of the engine based on RPM. If the engine
speed RPM exceeds this setpoint, the governor will shut in and remain
closed until the start sequence is re-initiated. The terminal control
display will annunciate the message “OVRSPEED”. This message will
be displayed until the engine reaches a complete stop and the operator
presses any button on the governor interface, or the engine is restarted.
THIS FEATURE SHOULD NOT BE USED AS THE PRIMARY
OVERSPEED SHUTDOWN. IT IS MEANT AS A REDUNDANT
SHUTDOWN DEVICE ONLY.

HISTPRES – High start pressure. While starting and until the warmup
timer expires, if the manifold pressure exceeds the governor HISTPRES
setpoint, the governor will close and remain closed until the start
sequence is re-initiated. The terminal control display will annunciate
“HISTPRES” until the engine reaches a complete stop and the operator
presses any button on the governor interface, or the engine is restarted.

2-5
Form GOV OM 11-02

ENGINE NO
STOPPED

STOPPED
(DISPLAYED)

30 SEC.
TIMER

STRAIN
BAD
GAUGE WAIT
CHECK

VALVERDY
(DISPLAYED)

RPM>
NO
CRANK
Setpoint

YES

PURGE
(DISPLAYED)

PURGE
TIME
EXPIRED

2-6
Form GOV OM 11-02

RPM
NO
>
SWITCH
POINT

CLOSE
CONTACT

SUPPLYPRS NO
>
SUPPLYPRS
Setpoint

STARTING
(DISPLAYED)

REGULATE
MANIFOLD
PRESSURE

START NO
TIMER
EXPIRED

RPM > NO
IDLE SPEED

2-7
Form GOV OM 11-02

WARMUP
(DISPLAYED)

RAMP ENGINE
TO MINIMUM
SPEED

HOLD ENGINE
TO MINIMUM
SPEED

WARM UP NO
TIMER
EXPIRED

GOV ON
(DISPLAYED)

RAMP ENGINE
TO
SETPOINT

SPEED
GOVERN
ON

2-8
Form GOV OM 11-02

Section 3
GOV INSTALLATION

3-1
Form GOV OM 11-02

1. Do not install the valve in such a manner that will trap gas pressure on the INSTALLATION
downstream side of the valve. DO’S AND DON’TS
2. Always provide an adequate supply pressure for the application.
3. Where the gas is dirty, or has liquid suspension, install a separate pilot gas
supply with an external filter.
4. Supply the valve with +24 Vdc, 1.0 amp at the valve. Using small gauge
wire may cause a large voltage drop resulting in an inadequate power
supply.
5. Do not create ground loops when connecting the GOV.
6. Never install governor wires in the same conduit with any other wiring.
7. The flow signal on the GOV is loop powered.
8. Never paint the valve.
9. Never replace the valve with that of a different configuration.
10. Do not install the valve in such a manner where condensate may build up
inside the electronics housing.

NOTE: The use of resistor spark plugs and/or resistor spark plug leads is
strongly recommended. This plus adherence to points 4 through 6 above
will avoid most RFI noise problems.

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Form GOV OM 11-02

The GOV10 Gas Engine Governor is to meter fuel gas only and should not SAFETY WARNING
be used as a main fuel system shutoff valve. A separate fuel shutoff valve
must be installed UPSTREAM of the GOV. If no venting is provided, the
fuel system must be such that no gas is trapped downstream of the GOV.
It is the customer’s responsibility to insure that purge times are completed
and the ignition system is turned on before fuel pressure is allowed to
reach the GOV.

The gas metering valve should be inspected immediately after unpacking. VALVE PRE-
Check for any damage that may have been incurred during shipping. If there INSPECTION
are any questions regarding the physical integrity of the valve, call the Altronic
distributor that supplied the Governor. If possible, keep the original shipping
container. If future transportation or storage of the valve is necessary, this
container will provide optimum protection.

Ensure that the GOV received matches the model no. and configuration of the
fuel valve to the packing list and if possible, to the purchase order. The top
plate of the GOV contains information pertinent to that particular valve, for
example, embedded acceleration schedule, external filter, flow feedback
information, ANSI 8-bolt flange, etc.

The GOV10/50 Governors are CSA certified for Class I, Group D, Division 1 or 2
hazardous locations.

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Form GOV OM 11-02

If the information matches correctly, then it is the appropriate Governor for your
engine application.

When considering where to place the GOV10 Gas Engine Governor it is GENERAL
recommended that several issues be kept in mind.
CONSIDERATIONS
• The valve should be located away from any extreme sources of heat.
Operating ambient temperature –40°F to +185°F / –40°C. to +85°C. Do not
expose the governor to temperatures higher than indicated here.
• Supply gas temperature will not have an effect on the flow of fuel through
the acceptable operating temperature range of the valve (see above). The
fuel gas temperature should not exceed 185°F / 85°C.
• Pressure variation in the fuel supply does not affect the gas flow through the
valve, providing that the pressure does not drop below the minimum
required for that fuel flow.

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Form GOV OM 11-02

The GOV Gas Governor can be mounted in either a horizontal or vertical INSTALLATION
position. Ideally, the installation will allow for at least 10 pipe diameters of LOCATIONS
straight pipe (15” for 1.5” piping) on the downstream side of the valve. This
helps to ensure a consistent and smooth flow through the metering orifice,
providing a more accurate fuel flow measurement.

However, straight runs of piping to and from the valve are not required, though
some performance degradation in flow meter accuracy will result. Flow
measurement adjustments can be done to increase the accuracy of the flow
meter once the valve has been installed.

To optimize the engine’s response to fuel flow changes, mount the GOV no MOUNTING THE
more than 10 feet from the fuel manifold for optimum performance. GOV GAS
METERING VALVE
The valve is normally mounted and supported via the 4 or 8 bolt flanges, or the
optional mounting plate. Threaded holes (5/16”-18) are provided on the bottom
of the valve that can be used for securing the unit to a flat surface.

The GOV10 is supplied with SAE 61 series 4-bolt flanges for 2” pipe or ANSI
8-bolt, class 300 flanges for 2” pipe. The GOV50 is available only with the 2”,
SAE 61, 4 bolt type flanges.

Control gas pressure of at least 25 PSIG above fuel manifold pressure GAS PRESSURE
must be available at all times for valve actuation muscle. If fuel pressure to REQUIREMENTS
the GOV inlet (upstream fuel pressure) is always the required 25 PSIG above
fuel manifold pressure (downstream pressure), the valve will operate with
internal control gas pressure from the fuel supplied to the engine. If the required
muscle gas is not available, an external gas line must be routed from an
adequate gas pressure source to the valve pilot port. Control gas is normally
bled to the downstream side of the valve. When using an external control gas
line, the line must have a shutoff valve that closes during engine shutdown.
Control gas volume required is 3 SCFM.

WARNING: Maximum gas pressure to the valve must not exceed 400 PSIG
(CSA rating is for 400 PSIG).

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Form GOV OM 11-02

VENT

RELAY NORMALLY OPEN

s VENT VALVE

ANALOG FUEL
s CONTROL
SIGNAL

SUPPLY ENGINE

NORMALLY CLOSED GOV10 GAS

SHUTOFF VALVE METERING
VALVE

STANDARD INSTALLATION1

RELAY

ANALOG FUEL
s s CONTROL
SIGNAL

SUPPLY ENGINE

NORMALLY CLOSED NORMALLY CLOSED GOV10 GAS

SHUTOFF VALVE SHUTOFF VALVE METERING
VALVE

STANDARD NON-VENT INSTALLATION

1
This is the preferred installation of a GOV valve.

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Form GOV OM 11-02

RELAY

PILOT
GAS FILTER

ANALOG FUEL
s s CONTROL
SIGNAL

SUPPLY ENGINE

NORMALLY CLOSED NORMALLY CLOSED GOV10 GAS

SHUTOFF VALVE SHUTOFF VALVE METERING
VALVE

STANDARD NON-VENT INSTALLATION

WITH EXTERNAL FILTER

VENT

RELAY NORMALLY OPEN

s VENT VALVE

PILOT
GAS FILTER

ANALOG FUEL
s CONTROL
SIGNAL

SUPPLY ENGINE

NORMALLY CLOSED GOV10 GAS

SHUTOFF VALVE METERING
VALVE

STANDARD INSTALLATION
WITH EXT. FILTER AND VENTING

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Form GOV OM 11-02

The following sections apply to the electrical requirements of the installation of ELECTRICAL
the GOV Gas Metering Valve. All efforts should be made to conform to the CONNECTIONS
applicable electrical code with regard to hazardous environment installations.

CAUTION: The system power should be OFF before any of the valve
wiring is connected or disconnected. Failure to do so may result in
damage to your engine and/or the GOV10/50.

Hazardous locations are those areas where a potential for explosion and fire HAZARDOUS
exist because of flammable gases, vapors or finely pulverized dusts in the LOCATIONS
atmosphere, or because of the presence of easily ignitable fibers or flyings2.

Because of the necessary requirements, the wiring methods to be used are

through threaded, ridged metal conduit with termination fittings approved for the
location. The entire assembly is to be explosion-proof and where necessary, to
employ flexible connections approved for Class I Division I.

The GOV10/50 requires 20 to 32 Vdc, 1 amp electrical power at the connector POWER
or harness. Power should be steady and uninterrupted. Power dips of any REQUIREMENTS
duration below 20 volts will cause the GOV valves to close and to stay closed
until a new start sequence is initiated. The GOV electronics are electrically
isolated, but if excessive voltage noise (AC ripple) is found, it may be filtered out
using a capacitor (300 to 1000 microfarad at 50Vdc is suggested). The
capacitor should be placed at the source of the noise.

The GOV10/50 come standard with a 3/4” NPT conduit entry, and 10 feet of CONNECTION
leads. The threaded conduit entry is for use in electrically classified areas. LEADS
Connector pin assignments and wire colors are given in the chart on the
following page.

2
National Electric Code; articles 500-517. Canada Electric Code; section 18.

3-8
 Form GOV OM 11-02

REF WIRE COLOR SERVICE WIRING CHART

A WHITE 24Vdc (+)
B GREY 24Vdc common (–)
C BLUE Remote Speed Demand 4-20mA Input
D WHITE/BLUE Remote Speed Demand 4-20 mA Return
E YELLOW Fuel Flow Feedback (4-20mA out 1)
F WHITE/YELLOW Fuel Flow Feedback (4-20mA out 1 RTN)
G RED/BLUE Magnetic Pickup (+)
H WHITE/BLACK Magnetic Pickup (–)
J YELLOW/RED RPM Feedback (4-20mA out 2, 0-1000 RPM)
K YELLOW/BLACK RPM RTN (4-20mA out 2, 0-1000 RPM)
L GRAY/RED MODBUS (+)
M WHITE/RED/GRAY MODBUS (–)
N WHITE/GRAY MODBUS RTN
P WHITE/VIOLET Discrete Input 1+ Local/Remote (not normally used)
S WHITE/YELL/BRN Discrete Input 1– Local/Remote (not normally used)
T WHT/ORG/BLUE Discrete Input 2+ Clear warm up timer (not normally used)
U WHT/RED/GRN Discrete Input 2– Clear warm up timer (not normally used)
V WHT/YELL/ORG Discrete Output 1+ Speed switch (not normally used)
W WHT/YELL/RED Discrete Output 1– Speed switch (not normally used)
Y GREEN RS-485 Communication (Rx)
Z BROWN RS-485 Communication (Tx)
a WHITE/BRN RS-485 Communication (Gnd)
b WHT/RED/BRN Pressure transducer (+)
c W/GRN Pressure transducer (–)

3-9
Form GOV OM 11-02

All wiring to the GOV should be of a shielded, twisted pair type. Valve wiring WIRING
should be run in separate conduit. Never run the wiring in conduit containing
wires with AC service, or with wires connected in any way to the ignition system
of the engines.

24Vdc power wire size is dependent on the distance from the supply to the
GOV. Wires must be large enough to insure at least 20 Vdc at the GOV
terminal connection.

The 4 to 20 mA wiring for remote speed demand and fuel flow feedback, and
RS-485 communications wires may be up to 350 feet long if large gauge wire
(16 AWG) is used. Noise is always a consideration on these signals, so the
wire length should be kept as short as possible. Smaller gauge wire (20 AWG)
may be used for distances under 100’.

Magnetic pickup wiring should be 22 AWG twisted pair, shielded wire with a
length no longer than 50 feet.

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Form GOV OM 11-02

The discrete output speed switch is used as a shutdown or malfunction feature TRANSIENT
based upon low fuel gas pressure. If RPM exceeds the SPDSWICH setting and SUPPRESSION
the purge timer expires, the contact will close. In addition, the contact will open
upon any of the shutdown features programmed into the GOV 10. These
shutdowns are listed further in the manual. If engine speed drops 2 RPM below
the set point the contact will reset into the open position. This discrete output
has a 3 amp capability and is suitable for driving a small solenoid valve. Using
this contact makes possible the automation of the upstream block valve
operation. The discrete output is paralleled with the purge timer.

A transient suppression board (part no. TS-100) is available which provides

excellent isolation to/from the Governor and its associated control system. If
protection is necessary to achieve Class I, Division I or II electrical standards,
the transient suppression board and an approved explosion-proof (ExP) box
should be considered. The ExP box (part no. 810080) is available from Altronic
or may be supplied by the user. The recommended box for use with the
transient suppression board is Adalet model no. XJWH or equivalent

Wiring diagrams and layouts are available at the back of this manual.

3-11
Form GOV OM 11-02

Section 4
DISPLAY TERMINAL ASSEMBLY (TCA-100)

INPUT SPEED

- +
DISPLAY SETPOINT MODE

4-1
Form GOV OM 11-02

The Governor Display Terminal Assembly is a small panel used for man- DESCRIPTION
machine interface with the GOV governors. The front of the Display
Terminal consists of two (2) LED displays and six (6) function keys. The
top LED always displays numeric values and the bottom LED always
displays the name of the value being displayed on the top LED or a
status message such as “Valve ready” or “Gov On”. The function keys
are arranged in three (3) groups with two (2) keys in each group. The
function key groups are labeled DISPLAY, SET POINT, and MODE. In
the DISPLAY group the key functions are designated as INPUT and are
labeled with an UP ARROW on one key and a DOWN ARROW on the
other. These two keys are used to scroll up or down though the
parameters displayed on the terminal. In the SET POINT group, the
keys function is designated as SPEED (the most often used function
used is the changing of the speed setpoint). The associated keys are
labeled with a plus (+) and (-) signs. The purpose of these keys is to
change the value of any programmable parameter displayed in the LED
box. The (+) key will increment the value and the (-) key will decrement
the associated value. In the MODE group, the keys are designated SET
UP and NORM. When the NORM key is pressed, read only values are
displayed. When the SET UP key is used, the operator has access to
the programming values and may edit them.

The GOV Gas Engine Governor controls fuel flow to the engine, and thus SETTING GAINS
engine speed, by using PID control loops. PID control loops are
commonly used in the instrumentation/control industry to control a variety
of functions. PID stands for proportional, integral and derivative control.
These control loops are a way of combining three gains (though only
proportional and integral are the most commonly used) to change one
output level.

Proportional Control – proportional control is an adjustment of engine

speed determined by the relationship of engine speed (Ng) to the speed
set point. Actual RPM from the RPM set point causes an error signal.
This error signal is the engine speed adjustment. The control loop is
scaled to a full-scale output. The error signal is multiplied against the
proportional gain to generate a portion of the full-scale output.

4-2
Form GOV OM 11-02

Thus, the greater the error (Ng vs. set point), the greater the response
(an increase/decrease in speed). Due to response lags in the system
(includes engine), proportional control can only be adjusted a limited
amount. When proportional gain is set above the maximum the system
will tolerate, speed instability will result.

Integral Control – to add more gain to a PID control loop without

causing instability, an integrator is used. An integrator adds gain to the
control loop output in even integrals of time. Thus the larger the error,
the larger the integral contribution becomes, and the system output
increases more rapidly. Also, when the error returns to zero, the
integrator will not return to its original value until the error transitions from
a positive error to a negative error before an increasing integrator will
begin decreasing, or vice versa.

There are a few things to remember when setting governor gains. A

speed governor is receiving speed information only. A speed governor is
a reactionary device. The governor cannot anticipate when a speed
change is to occur, only after a speed change has occurred. A speed
governor only recognizes speed and the governor corrects fuel flow to
achieve the set point. On a loaded engine, if the power cylinders misfire,
speed will drop very rapidly (in one crankshaft revolution or less). The
GOV cannot prevent rapid speed drops caused by misfires, it can only
add fuel to the manifold to help the remaining cylinders pick up the load
and correct the engine speed back to the set point. DO NOT CONFUSE
ENGINE INSTABILITY CAUSED BY GAINS SET TOO HIGH WITH
SPEED CHANGES CAUSED BY MISFIRES. Gains instability is
characterized by steady speed oscillations, with error amplitude in both
directions (positive/negative) and remaining constant. Speed changes
caused by engine misfires are characterized by their erratic error
amplitude and frequency. If speed instability is present, gains need to be
lowered. If misfiring is present and cannot be corrected, the gains will
have to be as high as possible.

4-3
Form GOV OM 11-02

Governor gains set high enough to allow good load change response at GAINS WITH THE
full load and speed conditions will often cause speed instability at ENGINE IDLING
minimum speed and no load. To compensate for this fact, the GOV Gas AND AT NO LOAD
Engine Governor has available a separate set of PID gains for use at
minimum speed and no load. These gains are called IDLE GAIN and
IDLE INTG. To set the IDLE GAIN and IDLE INTG the following steps
should be done:

1. Set the GOV to LOCAL MODE.

2. The GOV factory default for these gains is 25. With a gain this low
it may take the engine far too long to accelerate to minimum speed.
If this is the case, set the IDLE GAIN and IDLE INTG to 30. The
IDLE GAIN and IDLE INTG may be changed while the engine is
running.
3. Unload the engine and set the speed set point to the minimum
speed value.
4. While watching engine speed fluctuation, begin to raise the IDLE
GAIN by a value of ten at a time. At this time, do not be concerned
with how long a speed error persists (corrected later), only with
how great the error amplitude is. If speed fluctuation does not
change, keep raising the IDLE GAIN until the fluctuation gets either
better or worse. If speed fluctuation lessens (gets better), keep
raising IDLE GAIN until the fluctuations starts to increase (get
worse). When this happens, lower the IDLE GAIN by a value of 1
or 2 at a time until such time as the engine speed fluctuation is at a
minimum. IDLE GAIN is now at its optimum setting. If speed
fluctuations increase the first time you raise IDLE GAIN, work this
procedure in reverse, i.e. lower IDLE GAIN until an improvement is
made, then worsens, then raise IDLE GAIN gradually until the
optimum setting is reached.
5. Now when a speed error occurs (even if the error is a small one)
notice how long the engine speed remains off the set point. Begin
raising the IDLE INTG by a value of ten at a time until recovery to
set is faster (gets better). Keep raising the IDLE INTG until the
engine speed begins to “overshoot” each time the governor makes
a correction. Then lower the IDLE INTG by values of 1 or 2 until
the “overshoot” disappears. IDLE INTG is then at its optimum
setting.

4-4
Form GOV OM 11-02

Once most engines are running well unloaded at minimum speed, they USING LOAD GAIN
must be sped up before attempting a load. When an engine is running EFFECTIVELY
above minimum speed, different gains are needed to run the engine well
at operating speed during and after loading. Some engines are hard to
keep stable at operating speed unloaded if the gains are set to work well
when the engine is loaded. To ease this situation, the GOV uses a
function called LOAD GAIN. LOAD GAIN is a number, which is
multiplied against the fuel flow and is added to the integral gain, thus
increasing integral gain more when the engine is loaded then when it is
unloaded.

The Governor Terminal Interface Assembly displays the GOV’s GAINS WITH THE
proportional gain as PROP GAIN and its integral gain as INTR GAIN. ENGINE AT SPEED
Initially, run the engine at normal operating speed unloaded. To set AND LOADED
PROP GAIN and INTR GAIN the following procedure should be
performed.

1. Set LOAD GAIN as in previous section above.

2. Using the previous procedure, adjust the PROP GAIN instead of
IDLE GAIN and INTR GAIN in place of IDLE INTR. Get the engine
speed as stable as possible with the engine unloaded.
3. Load the engine. If the engine will not load up without dying, try
increasing LOAD GAIN value by 2 each time. If the engine speed
becomes unstable at no load before the engine loads well, you will
have to start lowering the LOAD GAIN and increasing INTG GAIN
until both conditions have been satisfied. PROP GAIN and INTR
GAIN may be adjusted while the engine is running.
4. Usually, once an engine is loading up it will unload satisfactorily
also. Watch the engine RPM’s as the engine unloads. Engine
speed will increase some, but should return to the setpoint quickly.

4-5
Form GOV OM 11-02

The GOV10/50 Governors provide fuel flow measurement as an option. FUEL FLOW
The measurement is calculated using differential pressure across an MEASUREMENT
orifice plate in the valve body. The governors are calibrated to a flow
standard using compressed air on a flow bench assembly. The accuracy
of orifice plate measurements is always subject to piping configuration
errors. Normally at least 10 pipe diameters of straight pipe is required
before the orifice plate to maintain accuracy. This is often impractical to
do when installing the GOV on an engine. The best way to insure
accuracy is to measure fuel flow to the engine with a meter run, turbine
meter or other flow measurement device. Compare the resultant flow
values with those of the GOV Gas Engine Governor. If an error is
present the FLOW OFFSET and FLOW ADJUST settings can be used to
correct the error.

1. Run the engine unloaded and at minimum speed. Record the flow
readings from the GOV and the independent flow measurement
device.
2. Run the engine at full load and at maximum speed, again recording
the fuel flow values.
3. Increase or decrease the FLOW ADJUST value until the flow
readings are acceptably close.
4. If flow accuracy is a concern while the engine is unloaded, re-
record flow values when the engine is running unloaded. Use the
FLOW OFFSET (increase or decrease) until the readings are again
acceptably close.
5. Load the engine again and compare the fuel flow readings. If
necessary, change the FLOW ADJUST value until the readings are
matching.
6. Continue the procedure until the fuel flow readings in both the
unloaded and loaded conditions. This procedure is similar to setting
zero and span on other measurement devices. Changing the
FLOW OFFSET at the low end will change the flow reading at the
upper limit. Changing FLOW ADJUST at the upper limits will also
change the fuel flow readings on the lower limits. Each repetition
of changes will decrease the error on both ends until the loaded
and unloaded fuel flow readings are acceptable.

4-6
Form GOV OM 11-02

VIEWING DATA NAMES AND VALUES KEY PAD

OPERATIONS
The Governor Terminal Interface Assembly’s bottom LED always
displays the parameter name of the value displayed in the top LED. For
instance, when the bottom LED displays “RPM”, the value being
displayed in the top LED is engine speed in revolutions per minute.

SCROLLING DATA POINTS

Press the NORM button. Press the S key slowly several times. Notice
the parameter names change in the bottom LED and the corresponding
numeric values in the top LED. Pressing the T key will scroll through
the display in the reverse order. By pressing the SET UP key, then the
arrow keys, a different list of parameters is available for display.

CHANGING VALUES

Press the SET UP key. Using the S key, scroll the data points until
reaching “SET RPM”. If the top LED value is less than the maximum
engine RPM, use the + key until the value reaches the desired setting.
The same is available with the – key if the desired value is less than the
current setting. All programmable settings of the GOV Gas Engine
Governors are set in this manner. If the operator presses no key within
45 seconds of accessing another menu (setup or programming), the
control interface display will default to the NORM operating position (see
next page).

4-7
Form GOV OM 11-02

DISPLAYED VALUES DESCRIPTIONS – NORMAL MODE OPERATING MODES:

NORMAL
RPM Engine speed in revolutions per minute.
UPSTREAM Supply gas pressure in PSIG.
DOWN STM Pressure in the GOV down stream of the poppet and
upstream of the
measuring orifice in PSIG.
ACT OUTP Output of the onboard DAC (digital to analog
converter) to the actuators voice coil in digital counts.
Actuator output is a good way to check what
percentage of available governor that the engine is
using. The base count is approximately 200 (poppet
closed) and is 4095 (full open). At about 1000 counts
the governor is ¼ open and at 2000 counts is
approximately ½ open.
WARMTIME Displays the time in seconds remaining in the warm
up timer.
SETPOINT SET POINT is the speed demand value in RPM at
which the GOV is currently controlling. When the
speed settings have not been changed, SET POINT
will equal the speed setting of the current operating
mode (local or remote). When the speed setting is
changed or when the engine is first started and is still
accelerating, SET POINT will equal the value output
by the GOV’s speed ramp until the engine speed
matches the new speed setting. While the engine is
not running, the value will be zero.
RMT DMND Current value in RPM of the remote speed demand 4
to 20 ma signal.
TORQ SP Torque set point is a min select for speed demand
AIR MANI This is an optional external pressure transducer
located on the scavenge air. It is measured in PSIG.
When this option is used, the start schedule of the
engine becomes based in part on this measurement.
FUELTEMP Fuel temperature in °F.
FUEL FLOW Fuel flow in SCFM. GOV 10-(0-500 SCFM) GOV 50-
(0-1000 SCFM)
HORSEPWR Calculation of estimated horsepower based on fuel
flow (SCFM *HP-ADJ + HP-OFFSET). The accuracy
of this measurement may vary depending on the
health of the engine, ambient air temperature, heating
and value of gas, etc. An engine analyst should
calibrate this measurement to the engine with the
most accurate point being the engine running at max.
speed and full load.
TORQUE Calculation of torque based on the estimated
horsepower.

To look at any of the above values, perform the following procedure:

1. Push the NORM key.
2. Push the S or T keys to scroll through the available data points.
If no key is pressed within 45 seconds of accessing another menu (setup
or programming), the display will default to the NORM operating mode.

4-8
Form GOV OM 11-02

SCALING
The scaling for fuel flow feed back is as follows
• GOV10 0-500 SCFM
• GOV50 0-1000 SCFM
The scaling for RPM feedback is 0-1000 RPM.
The scaling for HP feedback is 0-10,000 HP.
The scaling for Torque feedback is 0-180,000 ft.lbs.

DISPLAYED DIAGNOSTIC MESSAGE

POWER UP Displayed when the valve is powered up with >19Vdc

and remains displayed until any key is depressed.
WAIT Displayed when pressure is trapped downstream of
the valve or if a transducer has failed.
OVERPRESS Displayed when down stream pressure exceeds the
over pressure set point.
HI PRESS Displayed when down stream pressure exceeds the
Hi start pressure set point.
OVERSPED Displayed when RPM exceeds over speed set point.
NOSIGNAL No magnetic pickup signal. If the frequency input
from the magnetic pickup drops below 35Hz from
more than 250ms, the governor will close and remain
closed until the start sequence is reinitiated. The
control interface display will annunciate the message
NOSIGNAL. This message will be displayed until the
engine reaches a complete stop and the operator
presses any button on the governor interface or the
engine is restarted.
LOWPRES Low supply pressure. An alarm condition during
starting or running. If the upstream pressure drops
below the governors programmed “supply pressure”
set point, the governor will close and remain closed
until the start sequence is reinitiated. The control
interface display will annunciate the message
LOWPRES. This message will remain until the
engine reaches a complete stop and the operator
presses any button on the display or the engine is
restarted.
TORQ S/D Unit has reached the Torque shut down set point, the
Governor will close and remain closed, until the unit
reaches a complete stop and the start sequence is
reinitiated. The control interface display will
annunciate the message TORQ S/D. this message
will be displayed until the engine reaches a complete
stop and the operator presses any button on the
governor interface or the engine is restarted.

NOTE: Loss of 24Vdc or voltage dropping below 19Vdc will be

annunciated with Version 1 software by a flashing display of
OVERPRESS; with Version 2 software, the display will show POWER
UP. Both flashing annunciations may be cleared by depressing NORM
key after 45 seconds.
4-9
Form GOV OM 11-02

Press the SET UP key to use the setup mode. Setup mode provides a OPERATING MODES:
list of programmable values that the operator may change. SETUP

The following is the procedure to change the numeric values in the SET
UP mode.
1. Push the SET UP key.
2. Push the S or T keys to scroll through the available data
points.
3. Use the + or – keys to increment/decrement the value
indicated till the desired value is reached. For
LOCAL/REMOTE, pushing the + key will select remote
operations. Pressing the – key will enable local operations.
4. Press the NORM key to return to the Normal mode.
5. Any changes made while in the Setup Mode must be
SAVED by entering the Programming Mode and then using
the SAVE function. Unless this procedure is used, values
entered in the setup mode will take effect but will be lost if
the power is lost or cycled.

DISPLAYED VALUES DESCRIPTIONS – SETUP MODE

SET RPM Governor speed set point in RPM. While in Local

0-999 RPM mode, the engine will run at the speed entered in the
Default = 270 SET RPM.
START PS The GOV will maintain fuel manifold pressure at the
0-50.00 PSIG START PS while the engine is cranking.
Default = 4.50
SRTRATIO For engines that do not have “jet assisted” starting
0-10.00 but rather are using the equivalent of chain driven
Default = 0.00 turbo chargers. This is a numeric ratio multiplied
against the measured air pressure and added to the
start pressure to create the starting set point (see
START PS). Using the value of 0 will negate the
effect of the start ratio.
SRT TIME During engine start the GOV acts as a fuel regulator
0-99.0 Secs. against the set point value (see START PS). When
Default = 3.0 the engine reaches minimum operating speed the
GOV switches over to a speed governor. This
parameter determines the length of time (in seconds)
that the GOV maintains the START PS setting
(typically 3-5 seconds).
HiStPres Shut down on high fuel manifold pressure during
0-50.00 PSIG start.
Default = 30.00
OvrPress Shut down on high fuel manifold pressure while
0-50.00 PSIG running.
Default = 60.00

4-10
Form GOV OM 11-02

LOCAL/ Switch between local and remote control.

REMOTE
FLOW ADJ FLOW ADJUST will multiply the fuel flow
0-99 measurement calculation. FLOW ADJUST is factory
Default = 47 calibrated and should not be changed unless a
customer wishes to match flow measurements within
an existing system. FLOW ADJUST will affect flow
reading more at high flow than at low flow. DO NOT
ZERO.
FLOW O/S Flow offset is a linear factor used to calibrate the GOV
0-99 flow measurement reading. FLOW OFFSET is a
Default = 0 factory calibrated setting and should not be changed
unless the customer wishes to match flow measure-
ment with an existing system. In such a case the flow
measurement value will be changed linearly from zero
to a maximum reading by the amount FLOW OFFSET
is changed.
HP ADJ Horsepower Adjust should be set as the engine
0.01-320.00 analyst maps the engine and achieves maximum
Default = 8.00 rated horsepower for that unit.
HP O/S Horsepower Offset should be set as the engine
-32,000 to 32,000 analyst maps the engine and achieves minimum
Default = -500 speed, minimum load.
TORQ ADJ Torque Adjust (ft.-lbs.) is a factory set point and
0-64,000 should NOT be adjusted in the field.
Default = 5252
TORQ O/S Torque Offset (ft.-lbs.) is a factory set point and
-32,000 to 32,000 should NOT be adjusted in the field.
Default = 0
TORQLMIT Torque Limit (ft.-lbs.) is used for limiting the torque on
0-180,000 a unit that is driving either a centrifugal compressor or
Default = 100,000 a pump.
TORQ S/D Torque Shutdown is the value in ft.-lbs. at which the
0-180,000 governor will shut the unit down.
Default = 100,000
TORQGAIN Torque Gain – divide the actual gain by 10,000;
0-3.001 a gain of 1 is 0.0001 and a gain of 100 is 0.0100.
Default = 0
RAMP RATE Ramp rate is a set point that determines how fast the
1-20 GOV will increase or decrease fuel flow to the engine
Default = 10 when the speed setting is changed. RAMP RATE is a
number scale from 1 to 20, 1 causing the slowest
engine acceleration and 20 causing the fastest.
Initially set RAMP RATE to a value of 10 and adjust
as desired for maximum performance.
WARM UP This setting is the engine warm up time in seconds.
0-900 Secs. After engine starts and ramps to minimum speed, the
Default = 0 GOV will maintain minimum engine speed for the
timer value set regardless of the speed setting. The
GOV will accelerate the engine to the speed set point
only after the warm up time has elapsed. Setting the
value to 0 can disable the warm up timer function.
While the engine is stopped, the timer is zeroed.

4-11
Form GOV OM 11-02

PURGE Purge is a timer in seconds that will add a delay

0-99 Secs. between the starter system being enabled and the fuel
Default = 0 flow being admitted to the engine. This will allow the
customer to purge the fuel system downstream of the
governor. It is the customer’s responsibility to be sure
that the engine ignition is enabled before the purge
timer elapses. A value of 0 will disable the purge
function.
RPM DAMP The displayed RPM is an average over time. This set-
1-50 point may be operator adjusted to allow the RPM
Default = 30 display to be smoothed out. The valid set point range
is 1 to 50 (1 = no dampening, 50 = max. dampening).
OVERSPED Overspeed is an operator adjustable set point for
Default = 380 shutdown of the engine based upon RPM. If the
engine RPM exceeds this set point, the governor will
close and remain closed until the start sequence is
reinitiated. The control interface display will
annunciate the message “OVRSPED”. This message
will be displayed until the engine reaches a complete
stop and the operator presses any button on the
interface, or until the engine is restarted.
WARNING: THIS FEATURE SHOULD NOT BE
USED AS THE PRIMARY OVERSPEED
SHUTDOWN! IT IS INTENDED TO BE ONLY A
REDUNDANT SHUTDOWN DEVICE.
WALKRATE The WALKRATE limits the rate at which the fuel
0-100 pressure increases when the GOV transitions from
Default = 0 Regulator mode (startup) to Governor mode
(MINSPEED). 0 = disabled, 100 = 1 psi per sec.
FLOWDAMP The displayed flow is an average over time. This set
1-50 point may be operator-adjusted to allow the flow
Default = 20 display to be smoothed out. (1 = no dampening,
50 = maximum dampening).
BITNONE Select either 8-bit No parity (0) or 7-bit Odd parity (-1).
0 or -1 When in 8-bit No parity, BITNONE will be displayed.
Default = 0
4-20out1 4-20mA output 1 is a programmable output with five
Default = 1 selections:
0 - forces 20mA out.
1 - selects flow feedback.
2 - selects RPM feedback.
3 - selects HP feedback.
4 - selects TORQUE feedback.
4-20out2 4-20Ma output 2 is a programmable output with five
Default = 2 selections:
0 - forces 20mA out.
1 - selects flow feedback.
2 - selects RPM feedback.
3 - selects HP feedback.
4 - selects TORQUE feedback

4-12
Form GOV OM 11-02

Some set points in the GOV software are critical to the governor OPERATING MODES:
operation and once set should not be changed. These set points can PROGRAMMING
only be accessed in the programming mode. If changing programming
mode set points is required by the customer, they should be changed
only after fully reading the description of the values.

To change the settings in programming mode do the following steps:

1. Enter programming mode by simultaneously pressing the
3RD , 4TH and 6TH keys, counting left to right.
2. Use the S or T keys to scroll to the appropriate setting.
3. Use the + or – keys to adjust the numeric value to the new
value.
4. Use SAVE function of the programming mode to save value.
When the display reads “SAVE”, press the NORM key to
save all values entered in the setup and/or programming
modes, and to resume operations.

DISPLAYED VALUES DESCRIPTIONS – PROGRAMMING MODE

PLSE/REV PLSE/REV should equal the number of pulses the
0-999 magnetic pickup will output to the GOV in one
Default = 359 crankshaft revolution MINUS ONE.
IDLE SPD Term used to designate the speed where unit turns off
Default = 125 regulator mode and turns on governor mode. This
should not be set lower than engine cranking speed.
CRANKSPD When the engine speed is greater than CRANKSPD
0-99 and less than IDLE SPD, the GOV will assume that
Default = 10 the starter assembly is engaged. When the engine
speed exceeds the IDLE SPD, the GOV assumes that
the starter assembly is disengaged, that the engine
has lighted off and is at idle speed. At this time the
governor will stop controlling fuel manifold pressure
and begin to govern engine speed. The governor will
then ramp up the engine to either minimum operating
speed or a speed set point dependant upon the
WARM UP timer value.
SUPPLY PS When engine speed exceeds CRANKSPD and
0.0-400.5 upstream pressure exceeds SUPPLY PS, the GOV
Default = 20.0 will begin admitting fuel to the engine. If the purge
timer is set above zero, fuel will not be admitted until
the purge timer has timed out.
PROPGAIN PROPGAIN is a number that is used as the starting
0-350 value for the proportional gain in the GOV’s PID
Default = 250 speed control loop. This value will vary from engine to
engine. Use the factory default value as a starting
point. See further discussion on governor gains within
this section.

4-13
Form GOV OM 11-02

INTRGAIN INTRGAIN is a number that is used as the starting

0-350 value for the integral gain in the GOV’s PID speed
Default = 0 control loop. This value will vary from engine to
engine. See further discussion on governor gains
within this section.
LOADGAIN LOADGAIN is a value that is multiplied by fuel flow in
0-99 SCFM and is added to the integral gain in the GOV’s
Default = 25 PID speed control loop. LOADGAIN allows higher
gains to be used when the engine is under load vs.
unloaded conditions.
IDLEGAIN IDLEGAIN is the starting value used for proportional
0-999 gain when SETPOINT equals MINSPEED. IDLEGAIN
Default = 25 has no effect on governor performance when the
engine is running above the minimum speed. See
further discussion on governor gains within this
section.
IDLEINTG IDLEINTG is the starting value used for integral gain
0-999 when SETPOINT equals MINSPEED. IDLEINTG has
Default = 25 no effect on governor performance when the engine is
running above the minimum speed. See further
discussion on governor gains within this section.
POS PROP Proportional gain for position control.
40-125
Default = 70
PRESGAIN Proportional gain for pressure control.
0-350
Default = 100
PRES INTR Integral gain for pressure control.
0-350
Default = 50
MAX INTR MAXINTR is used as a limit on the GOV’s PID loop
0-16,000 integrator value. This limit prevents integrator windup.
Default = 16,000 The default value is 16000 and works well in most
cases.
MAXSPEED MAXSPEED should be programmed to the maximum
0-999 normal operating speed of the engine. The GOV will
Default = 330 not allow the LOCAL MODE speed set point to be set
greater than MAXSPEED.
MINSPEED MINSPEED should be programmed to the minimum
0-999 normal operating speed of the engine. The GOV will
Default = 270 not allow the LOCAL MODE speed set point to be set
less than MINSPEED.
SWTCHRPM Threshold for dry contact closure, Discrete output 1.
0-999
Default = 167
ModbsAdr ModBus Address.
Default = 1
SAVE When the display reads SAVE, press the NORM
button to store all parameters currently programmed
in the GOV into non-volatile flash memory. After
SAVE has been performed, all values will be retained
even if power to the GOV is turned off. Use the SAVE
function only with the engine stopped. If the display
should “lock up” when the SAVE feature is used
during running conditions (due to RFI noise), the
engine must be shut down and the power reset to the
GOV.

4-14
Form GOV OM 11-02

It is recommended that the operator have a good working knowledge of SETTING START
the engine to initialize these values. The values of starting pressures for PRESSURE
the listed engines below are for guideline purposes only.
• Clark 5 to 6 PSIG
• Cooper Bessemer 2-cycle1 7 to 8 PSIG
• Cooper Bessemer GMV/GMW2 See note 2
• Ingersoll Rand KVS, KVSR 3 to 4.5 PSIG
• Ingersoll Rand KVT 1.5 to 2 PSIG
• Superior 0.5 to 1.5 PSIG

The engines will usually light off with these pressures. If the engine
ignites but does not gain enough speed to keep running, increase the
START PS not more than 1 PSIG at a time until the engine maintains a
running condition.

If the engine lights off and immediately gains too much speed, decrease
START PS by ½ to 1 PSIG at a time until the engine ramps up speed
smoothly to the idle speed set point.

If the engine does not seem to be firing at all, do NOT arbitrarily increase
the START PS until ignition occurs. Be sure that the ignition system is
turned on. Watch the UPSTREAM pressure to be sure the fuel is being
turned on to the GOV. Be sure that the GOV has the required 25 PSIG
supply pressure above the manifold pressure.

SAVE and re-enter the NORM mode.

NOTE: DO NOT START THE ENGINE WHILE IN SETUP MODE.

1
Cooper 2-cycle engines with air injection valves may leak starting air pressure
into the fuel manifold. On these units, roll the engine on starting air and leave the
fuel turned off. Read DWNSTREAM on the display. Set START PS 7 to 8 PSIG
above the DWNSTREAM pressure with the fuel turned off.
2
Procedure for determining start pressure on GMV-GMW engines:
The start pressure on these engines will vary greatly depending on the amount of
manifold backpressure. This backpressure is caused during the crank sequence
by the starting air in the cylinders, which bleeds through the fuel inlet valve to the
manifold. The correct start pressure is 2 to 8 psig above the backpressure. To
determine the backpressure, crank the engine with the main fuel valve upstream
of the GOV in the off position. View the DWNSTRM reading on the governor
display during an attempted start. This value corresponds to the manifold
backpressure. Re-enable the fuel system. Set the starting pressure at 2.0 psi
above the measured backpressure reading. Attempt an engine start. If the fuel
is too lean, increase the start pressure by 1 psi. If 8 psi or more is programmed
the manifold backpressure, other errors exist within the engine control system.
System checks on ignition, turbo and/or jet assist are necessary. DO NOT
START THE ENGINE WITH THE ABOVE CONDITION AS ENGINE DAMAGE
MAY OCCUR.
4-15
Form GOV OM 11-02

To set the pulses per revolution (PLSE/REV), the number of holes on the SETTING PULSES PER
engine flywheel must be known or how many gear teeth will pass the REVOLUTION
magnetic pickup in one crankshaft revolution. If a gear is being used, the
gear ratio must be used in calculating the revolutions.
1. Enter programming mode from the Terminal Interface Assembly.
2. Use the S or T keys to scroll to the appropriate setting.
3. Use the + or – keys to adjust the numeric value to the new value.
The value must be one less than the actual number of pulses
present from the engine.
4. SAVE and re-enter NORM mode.

CRANK SPD tells the GOV Gas Engine Governor that a start sequence SETTING CRANK
has been initiated. CRANK SPD is a numeric value entered as RPM. A SPEED VALUE
value of 10 to 25 is generally acceptable. If the engine does not turn
very fast on the starter mechanism (50 RPM or less), set the CRANK
SPD closer towards a value of 10 RPM. If the engine turns faster on the
starter (90 to 100 RPM), set the CRANK SPD value towards 25 RPM.
1. Enter programming mode from the Terminal Interface Assembly.
2. Use the S or T keys to scroll to the appropriate setting.
3. Use the + or – keys to adjust the numeric value to the new value.
4. SAVE and re-enter NORM mode.

SUPPLYPRS tells the GOV when the main fuel block valve has been
opened. SUPPLYPRS is a numeric value entered in PSIG. When
UPSTREAM (pressure) is greater than SUPPLYPRS, the GOV will begin
to admit fuel to the manifold and maintaining DWNSTRM to START
PRS. The initial SUPPLY PRS value should be 10 psi below the actual
operating pressure.

The following is the sequence to set the SUPPLY PRS.

1. Enter programming mode from the Terminal Interface Assembly.
2. Use the S or T keys to scroll to the appropriate setting.
3. Use the + or – keys to adjust the numeric value to the new value.
4. SAVE and re-enter NORM mode.

4-16
Form GOV OM 11-02

Section 5
GOV MAINTENANCE

5-1
Form GOV OM 11-02

The GOV10/50 Gas Engine Governor has been designed to provide MAINTENANCE OF THE
reliable operation with a minimum amount of maintenance. To ensure GOV10/50 GAS ENGINE
optimum performance, periodic inspection and cleaning is necessary. GOVERNOR

Preventative maintenance issues can be integrated into the current

maintenance schedule of the engine. Most maintenance requires little
effort and no downtime of the GOV10/50 valve.

Corrective maintenance is to be done when the GOV10/50 Gas

Engine Governor begins to behave erratically. Procedures have been
generated to troubleshoot and to repair most minor issues.

• External Visual Inspection – Inspect the exterior of the valve for PREVENTATIVE
loose connections, frayed wires, or major structural damage. MAINTENANCE OF THE
• Cleaning – Exterior cleaning will aid in the visual inspection of the
GOV10/50 GAS ENGINE
GOVERNOR
external casing and ensure good connections. Ethyl alcohol or
mild soapy water can be used as cleaning agents.
• Maintenance Log – To facilitate troubleshooting and to establish
service schedules, a maintenance log should be kept on the fuel-
metering valve.
• Calibration – Flow calibration of the GOV 10/50 is performed in a
controlled environment before shipment. Since calibration of the
valve requires equipment not normally available in the field, it is
recommended that the valve be returned to the Altronic distributor
serving your area.
• Pilot Gas Filter – The internal pilot gas filter, if installed should be
changed every six (6) months or more frequently if necessary.

The only corrective maintenance procedures that field personnel may CORRECTIVE
be able to perform on the GOV 10/50 Gas Engine Governor are that of MAINTENANCE ON THE
GOV10/50 GAS ENGINE
regulator and pilot filter cleaning/replacing and poppet valve assembly
GOVERNOR
removal. Any other actions taken on the GOV 10/50 valve may cause
physical damage or loss of calibration and would require that the valve
be serviced for refitting or re-calibration.

5-2
Form GOV OM 11-02

The following section will cover the replacement or cleaning of the REGULATOR & FILTER
Regulator assembly. Before starting it is recommended that a clean CLEANING OR
flat work surface be prepared and the proper tools available. It is also REPLACEMENT
recommended that Valve Repair Kit be purchased which contains
items such as a spanner wrench, replacement O-rings, replacement
filter and O-ring lube.

Procedure for the cleaning/replacing of pilot filter

1. Using the spanner wrench, apply pressure in a counter-clockwise

motion and remove the regulator assembly.
2. DO NOT remove the regulator adjustment screw and nut. If these
are removed, the correct regulator settings (42 psid) cannot be
reset without returning the valve for re-calibration.
3. Check to see that the regulator does not interfere with the end
flanges. If there is no interference, continue to step 5. If there is
interference, the inlet flanges need to be removed (step 4).
4. Remove the 7 cap screws holding the inlet flange on using a 5/16”
Allen wrench. Remove the flange.
5. The filter O-ring (size 4470-200-012) and filter should now be
visible.

5-3
Form GOV OM 11-02

6. Carefully remove the O-ring for later use. Inspect the O-ring for
cuts and abrasions before reuse. If there is any physical damage
to the O-ring, it is to be replaced.
7. If you have a replacement filter and DO NOT want to reuse the
current filter, puncture the filter with a sharp object and remove it.
Continue to step 11.
8. If the filter is to be reused, use a dental pick to carefully ease the
filter out by its edges.
9. Backflush the filter with stoddard solvent or other cleaner.
10. Place the new or cleaned filter into the housing filter cavity, course
side down.

5-4
Form GOV OM 11-02

11. Place the O-ring in front of the filter to fasten it. When replacing
or reusing an O-ring, the proper lubricant should be used at
all times (i.e. Dow Corning lubricant #55).
12. Tighten the regulator assembly using the spanner wrench in
conjunction with a torque wrench (30 lb-ft of torque).
13. If the end flange had to be removed, place a small amount of O-
ring grease on the flange O-ring and re-install.

The following will cover the removal of the poppet valve assembly POPPET VALVE
(center section) from the GOV 10/50 Gas Engine Governor. Since the ASSEMBLY REMOVAL
center section is not serviceable in the field, a replacement must be
installed if on-site repairs are desired. These parts are included in the
Valve Repair Kit. In addition, replacement poppet valve assemblies
are sold separately.

Procedure for the removal of the poppet valve assembly

1. Remove the GOV 10/50 valve from the fuel line.
2. Remove the downstream flange, indicated by two (2) ridges, being
careful not to cut the O-ring. If needed, tap the flange upward with
a rubber mallet to ease removal.
3. Using a pair of snap ring pliers, remove the steel snap ring. Use
eye protection as the snap ring can release out of the assembly
unexpectedly.

5-5
Form GOV OM 11-02

4. Using the soft, rubber coated side of the snap ring pliers, pry out
the orifice metering plate (DO NOT DAMAGE THE INNER EDGE
IN ANY WAY).
5. Remove the upstream flange, being careful not to cut the O-ring.
Again, tap the flange with a rubber hammer to ease removal.
6. Put a 2” diameter PVC pipe over the downstream portion of the
center section. Using a rubber mallet, tap the PVC pipe until the
center section is removed from the housing. Do not press or
turn the poppet itself.
7. Coat the O-rings (3) of the new center section with O-ring
lubricant.
8. Insert the poppet assembly into the valve body with the cone
facing in the upstream direction.
9. Align the control pressure inlet of the poppet assembly with the
dowel insert of the control pressure transducer.
10. NOTE: The cone of the assembly, which does not have a cap
screw, is in line with the control pressure inlet of the assembly.
11. Click the center section in place by providing sufficient downward
force on the center section cone. In the field, this can be done by
CAREFULLY standing on the cone portion of the center section
when it is oriented vertically.
12. Replace the upstream flange (it has two ridges). Tighten down the
7 cap screws (6 lb-ft torque each).
13. Apply O-ring lubricant to the orifice O-ring. Firmly press the orifice
into the valve body at the downstream end. Ensure that the taper
faces the downstream side of the valve.
14. Replace the snap ring.
15. Replace the downstream flange. Tighten down the 7 cap screws
(6 lb-ft torque each).
16. Return the malfunction center section for refitting.

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Form GOV OM 11-02

Occasionally some form of foreign debris will make its way into the REMOVAL OF FOREIGN
metering housing and will become lodged inside. This will cause the DEBRIS FROM THE
POPPET ASSEMBLY
GOV 10/50 to malfunction in such ways as failure to shut-off (leakage)
and incorrect transducer readings affecting valve accuracy. Any
debris should be removed by using compressed air.

Procedure for removing foreign debris from

the metering housing and poppet assembly
1. Upon the removal of the poppet assembly from the metering
housing of the GOV 10/50, inspect the housing for any internal
damage that may have occurred.
2. Shop air can be used to blow away and clean any loose particles
that may have accumulated. DO NOT use any hard-edged
instrument to clean the valve housing.
3. Holding the center section in hand, apply instrument air to the
poppet assembly through the control pressure port (Pc).
4. The poppet valve will open with 30 to 70 psi air applied. Do not
exceed this range.
5. Using a soft edged device (i.e. Popsicle stick, Q-Tip, etc) hold
open the poppet valve. Do NOT use any hard-edged instruments
(i.e. screwdrivers) as this will damage the assembly.
6. Ensuring that the poppet assembly is clear of debris, release the
poppet valve.
7. Re-lubricate the O-ring seals of the poppet assembly and reinstall
as instructed.
CAUTION: Due to the strong nature of the shutoff spring within the
center section, DO NOT place your fingers near the poppet valve if it is
in an open position.

Replacement of the GOV 10/50 Fuel Gas Valve transducers can be TRANSDUCER
done in the field under the direction of the distributor or Altronic REPLACEMENT
personnel. The transducers that may be replace are the
• P(control) transducer
• P(offset) transducer
• P(supply) transducer
By replacing a transducer in the field, accuracy of the GOV 10/50 may
be slightly affected due to the small variances in transducer parts.
5-7
Form GOV OM 11-02

1. Remove the electronics housing cover.

2. Examine and make notes of the GOV10/50 electronic board
assembly (i.e. wire placement and orientations).
3. Unclip the affected transducer from the electronics board and
unscrew the board from the circuitry housing. Do not remove
more wires than necessary.
4. Using snap ring pliers, remove the snap ring of the affected
transducer.
5. With a small pry tool, remove the transducer from its housing.
6. NOTE: There is an O-ring placed on the underside of the
transducer. If this O-ring is damaged, it must be replaced.
7. Insert the new transducer into the appropriate position, taking care
to have the O-ring in place (within the cavity).
8. Re-insert the snap ring to hold the transducer in place.
9. Attach the wiring to the electronics board in the proper orientation.
NOTE: The red wire of the harness is on the downstream side of
the valve.
10. Re-assemble the electronics board to the electronics housing.
11. Install the electronics cover to the GOV10/50. Do NOT allow any
wires to become pinched when placing the cover on. Re-tighten
the cap screws to 40 in.-lb. torque. Maximum clearance between
the cover and the housing is 0.0015”.

5-8
Form GOV OM 11-02

Section 6
DRAWINGS

6-1
Form GOV OM 11-02

GOV10/50 INSTALLATION DATA SHEET

SETUP MODE PROGRAMMING MODE DISPLAY MODE

SET RPM PULSREV RPM
START PS IDLE SPD UPSTREAM
SRTRATIO CRANKSPD DOWN STN
SRT TIME SUPPLYPRES ACT OUTP
HiStPress PROPGAIN WARMTIME
OvrPress INTRGAIN SETPOINT
CONTROL LOADGAIN RMT DMND
FLOW ADJ IDLE GAIN TORQ SP
FLOW O/S IDLEINTG AIR MANI
HP ADJ POS PROP FUELTEMP
HP O/S PRESGAIN FUELFLOW
TORQ ADJ PRESINTR HORSEPWR
TORQ O/S MAX INTR TORQUE
TORQLMIT MAXSPEED
TORQ S/D MINSPEED
TORQGAIN SWTCHRPM
RAMPRATE ModbsAdr
WARM UP SAVE
PURGE
GENERAL INFORMATION
RPM DAMP
OVERSPED GOV. PART NO.
WALK RATE GOV. SERIAL NO.
FLOWDAMP ENGINE MANUFACTURER
BITNONE ENGINE MODEL NO.
4-20out1 UNIT NO.
4-20out2 DATE INSTALLED

6-2