Woodward EPG 524 Installation And Troubleshooting Manual page 13

Manual 82329
Gain and Stability
6. Set the IDLE potentiometer (pot) (if used) to mid-position.
7. Set the RATED speed pot fully counterclockwise (to minimum speed
setting).
8. Set the GAIN and STABILITY pots to mid-position.
9. Set START FUEL LIMIT clockwise (if applicable).
10. Start the engine or turbine, following manufacturer's instructions.
WARNING—START-UP
Be prepared to make an emergency shutdown when starting the engine,
turbine, or other type of prime mover, to protect against runaway or
overspeed with possible personal injury, loss of life, or property damage.
Verify:
•
MPU voltage between terminals 5 and 6 at least 1.5 Vrms while cranking?
(For small gears, it may be necessary to decrease the MPU clearance). Do
not decrease below 0.25 mm (.010 inches).
•
Actuator should go to maximum fuel position when the starter turns engine
or turbine. (If applicable, Start Fuel Limit must be fully clockwise.)
•
When the engine or turbine starts and comes to speed, the actuator arm
should move toward minimum-fuel position.
11. Adjust the GAIN pot to the stable region between low-frequency and high-
frequency oscillation.
12. If there is a low-frequency oscillation which does not stop when the GAIN
pot is adjusted, turn the STABILITY pot slightly clockwise and try the GAIN
pot adjustment again. Continue adjusting the STABILITY pot slightly
clockwise, then readjusting the GAIN pot, until the engine runs at a steady
speed.
If there is a high-frequency oscillation which will not stop, even when the
GAIN pot is fully counterclockwise, adjust the STABILITY pot slightly
counterclockwise until the high-frequency oscillation stops.
Speed Settings
13. Adjust the RATED SPEED pot for the desired rated speed.
14. Set the IDLE SPEED pot for the desired idle speed.
15. Close the IDLE/RATED switch.
16. Adjust transient response. Simulate a transient by manually bumping the
linkage.
To decrease settling time (may increase ringing) after a transient, turn the
GAIN pot clockwise slightly, then turn the STABILITY pot as required to
eliminate oscillation and to obtain desired response. Repeat if necessary.
Woodward
EPG Electrically Powered Governor
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