8290-189-EPG-installation-manual 8290-044
Installation and Operation Manual
This manual covers Electrically Power Governor (EPG) models 512/524 and
1712/1724. Refer to the appropriate manual or contact Woodward for information
about other versions of the EPG.

Application
The EPG is used to control the speed of diesel, gas, and gasoline engines. It can
also control the speed of gas turbines. Installation of EPG actuators is simple
because they require neither mechanical drive nor hydraulic supply.
The EPG handles prime movers with mechanical loads and generator loads
equally well. Generator sets which will be paralleled, however, require additional
appropriate switch gear, current and potential transformers, and the Woodward
Generator Load Sensor.
An EPG is a three-component system, requiring a magnetic pickup, speed
control, and actuator.
A battery charger must be used to keep the battery charged. Maximum steady
state current consumption is 4 A for the 12-volt models (512/1712), and 3 A for
the 24-volt models (524/1724).
Part Number Selection
Use EPG Model 512/1712 for operation in 12-volt systems. Use Model 524/1724
for operation in 24-volt systems.
Additionally, speed controls are available for four ranges of magnetic pickup
frequencies, for diesel engines and gas turbines, or for gasoline and gas
engines. Actuators have a double-ended output shaft for either clockwise or
counterclockwise rotation to increase fuel.
Speed controls and actuators must be compatible. Use the Part Number
Selection Table below (Table 1-1) to choose compatible EPG speed controls and
actuators.
The optional Start Fuel Limit feature allows setting a maximum actuator position
during start-up. The maximum position remains in effect until the engine reaches
the selected idle or rated speed. The limit may be adjusted out of the way by
turning the adjustment potentiometer fully clockwise.
The Dual Dynamics feature allows tailoring a special set of responses for
unloaded and loaded operating conditions. This type of control is often needed
for gas engines and other systems with non-linear fuel systems. A switch is used
to change between slow and fast dynamics.
Accessories
This manual includes some information about accessories frequently used with
EPGs.
To Parallel Generators
Add the Generator Load Sensor to the EPG in paralleled generator applications.
Woodward makes many accessories for paralleled generator applications.
To Decrease Acceleration and Deceleration
The Ramp Generator or an optional, external capacitor can be used to increase
the time to go from idle to rated speeds and vice versa. The Ramp Generator
provides a linear ramp with times adjustable to 25 seconds in a typical case. It is
useful in smoke-limiting applications. Use the 8271-909 with 24 V batteries and
the 8271-910 for 12 V batteries. The capacitor provides an exponential ramp with
times up to four seconds. Exponential means it changes (speed in this case)
rapidly at first but slows as it approaches its final value. See the typical wiring
diagram for capacitor requirements.
References
These publications can be obtained from your Woodward authorized Distributor
or AISF (Authorized Independent Service Facility). All are also available on the
Woodward website (www.woodward.com).
Catalog
52122
Product
Specification
04106
Manual
25070
82510
Title
Woodward Industrial Control Product Line Catalog
Title
Model 512/1712 & 524/1724 Electrically Powered Governors
Title
Electric Governor Installation Guide
Magnetic Pickups for Electric Governors
direction of rotation for increased fuel by choosing a suitable linkage.
If you are using a Woodward supplied installation kit, follow its instructions and
skip over Linkage Compatibility. Begin again with Installing the Magnetic Pickup.
Linkage Compatibility
Also match linkage linearity to the fuel control. Use a linear linkage as shown in
Figure 2-2 unless the prime mover has a carburetor or other non-linear fuel
control. See Figures 2-3 and 2-4 for a carburetor compensating linkage. Contact
Woodward if a linkage different from those shown is required. Incorrect linearity
matching can cause stable operation at some fuel settings but oscillation at other
fuel settings.
A return spring is included in the actuator. Do not use an additional return spring.
(Low force return springs that may be located in an engine’s valve cover usually
don’t affect EPG performance.)
Make sure that the actuator is capable of moving the fuel control to the maximum
and minimum limits. Let the fuel control limit actuator travel. Set the linkage so
that the actuator is just above minimum when the fuel control is at its minimum
stop and (except for Detroit Diesel engines) so that the actuator is just below
maximum when the fuel control is at its maximum stop. We recommend that
Woodward installation kits be used for Detroit Diesel engines.
Use good rod end connectors. The link connecting the actuator lever to the fuel
control lever must not be so long that it flexes when the prime mover is running.
Installing the Magnetic Pickup
Mount the magnetic pickup through a housing or rigid bracket. Make sure that
the sensed gear is of magnetic material. The gap between the pickup and the
outside diameter of the gear should be set to approximately 1.0 mm (0.04”) at the
closest point (radial runout). Using the pickup with small gears may require
spacing as close as 0.25 mm (0.010”).

If you cannot measure the gap directly, it can be set in this manner: with the
prime mover shut down, turn the pickup in (clockwise) until it touches the outside
diameter of a tooth. Then back out the pickup (counterclockwise) approximately
three-quarters of a turn. Run the gear slowly through 360 degree rotation to
check the clearance of the pickup. When the gap is set, tighten the jam nut
securely against the housing or bracket.
The standard pickup models require mating connectors, MS 3102R-18-3P. The
connectors are not furnished with the pickup, but may be ordered from
Woodward if desired. See manual 82510. Magnetic Pickups and Proximity
Switches for Electronic Controls, for more information
Wiring Instructions
Use a wiring diagram for the specific part number of your EPG system to make
all wiring connections. The wiring diagram is available from Woodward. Typical
wiring is shown in Figure 2-5.
Make all connections using insulated terminals. The wiring from actuator to
speed control and from the battery to the speed control must be as short as
possible. Maximum wiring lengths are:
Maximum Wiring Length Chart
EPG Model
14 AWG
(2 mm²)
Maximum Wire Length
12 AWG
(3 mm²)
512/1712
10 ft (3 m)
524/1724
20 ft (6 m)
35 ft (11 m)
75 ft (23 m)
The fuse and switch or circuit breaker must be in the non-grounded battery lead.
Use a fuse or circuit breaker as specified in the Switch and Fuse Requirements
Chart. Do not use a fuse of higher current rating. Starter relays make good EPG
power switches.
Installation Checks
Checks for all Applications
The following steps check only the speed control and actuator, which must work
correctly before paralleling the generator. Since most faults appear when the
prime mover is first run, this step-by-step approach eliminates most problems
before they occur. The main part of Chapter 5 (Troubleshooting) is doing these
checks.
If a Load Sensor is used, temporarily remove the wires at speed control terminals
11 and 12 and temporarily jumper terminals 11 to 12. The generator must not be
paralleled during these tests. If a Ramp Generator is used, temporarily remove
the wire at speed control terminal 10. If a capacitor is connected to terminal 10 to
provide a ramp between unloaded and loaded, it must be removed during this
test or calibration. Leave the idle-rated switch wiring connected. Do the checks in
the order indicated. Terminal numbers in this section refer to the speed control.
Check that all electrical connections are correctly made and terminal screws
are tight; the magnetic pickup is properly installed and the jam nut is tight;
the actuator and linkage are securely fastened. If start-fuel limit is present,
turn the adjustment fully clockwise during these tests. If dual dynamics are
present, set the switch closed for slow dynamics.

2. Do not start the prime mover now. Turn on governor power. If the fuse or
breaker opens as soon as power is applied, the battery polarity (terminals
14 and 15) is probably reversed. The actuator shaft can jump when power is
turned on, but must quickly come back to the minimum fuel position. Check
the battery voltage at terminal 1 (+) and 2 (–). It must be from 10 to 16 Vdc
for 512/1712 controls, and from 20 to 32 Vdc for 524/1724 controls.
Disconnect any wiring or jumper on terminal 7. Measure 7.2 ±1.0 V from
terminal 2 (–) to 7 (+) [terminals 2 (–) to 9 (+) for dual-dynamics control].
Reinstall the wiring to terminal 7 if voltage is correct. Do not use the control
if voltage is incorrect.
If idle speed is desired, connect a 50 kΩ potentiometer or fixed resistor to
terminals 9 and 10 as shown in the typical wiring diagram. To calculate the
value of a fixed resistor:
R = 17 kΩ
( Rated Speed
Idle Speed – 1 )
Put the idle-rated switch in the rated position or jumper terminals 9 and 10.
Measure the voltage from terminal 7 (+) to 2 (–). Put the idle-rated switch in
the idle position or remove the jumper. The voltage must increase. If it does
not increase, check the speed trim pot, if used, and the idle-rated switch
wiring.
If a signal generator with an isolated output is available, the failsafe and
actuator travel can be checked, Rated and idle speed can be preset. If a
signal generator is not available, skip to step 7.
Turn off governor power. Remove the magnetic pickup wires from terminals
5 and 6. Connect the signal generator to terminals 5 and 6. Set the output
between 2 and 10 Vrms. The wave form can be sine, square, or triangular.
Calculate the MPU frequency for idle and rated speeds (see part number
selection in Chapter 1).
Check Failsafe and Actuator Travel:
Set the signal-generator frequency to about half of idle speed. Set the idle
rated switch to rated. Turn the signal generator and governor power on. The
linkage must be at the maximum-fuel position. Except for Detroit Diesel
engines, verify that linkage travel is limited by the prime-mover fuel control,
not by the actuator stop. Turn the signal generator off and remove the
connections at terminals 5 and 6. The linkage should move to the minimum
fuel position. Verify that linkage travel is limited by the prime mover’s fuel
control, not by the actuator stop.
Preset Rated Speed:
Set the signal generator for MPU frequency at rated speed and connect it to
terminals 5 and 6. Put the idle-rated switch in the rated position. Set the
speed trim pot, if connected, to mid-position. Observe the linkage position.
If the linkage Is at the maximum fuel position:
Slowly turn the rated speed pot counterclockwise until the linkage just
begins to move to the minimum fuel position. Start Fuel (if present) must be
adjusted to the maximum clockwise position or the actuator will not move to
maximum.
If the linkage Is at the minimum fuel position:
Slowly turn the rated speed pot clockwise until the linkage just begins to
move to the maximum fuel position.
Continue to adjust the rated speed pot very slowly in the appropriate
direction, trying to stop the linkage between the minimum and maximum fuel
stops. Because it is not possible to stop the motion, cease adjusting when
the linkage moves slowly. The rated speed reference is now set very close
to desired speed. A slight adjustment when the engine is running will
achieve the exact speed.
Preset Idle Speed:
Preset idle speed only after presetting rated speed. Set the signal generator
for the MPU frequency at idle speed. Put the idle-rated switch in the idle
pos