Governor Controller Adjustment; Re-Checking Actuator Linkage; Checking The Actuator - Hobart 60PL20 Operation And Maintenance Manual

OM-2053

(4) Governor Controller Adjustment

The governor controller is located on the large panel to the left of the generator control box, as
viewed from the left side of the generator set. Before making an adjustment to the controller,
make sure the linkage between the actuator and the engine speed control is free and properly ad-
justed. There must be no lost motion or "play" in the linkage. Be sure the magnetic pick-up is pro-
ducing a strong, normal output.
The controller has two control potentiometers: the SPEED control potentiometer and the GAIN
potentiometer. Make the controller settings as follows:
NOTE: A very small screwdriver is required for this adjustment.
(a) With the engine warmed to operating temperature, use operating mode switch to bring the gen-
erator set from idle to rated speed.
(b) Adjust the SPEED potentiometer on the controller until the engine is operating at rated speed
(2000 RPM) . To INCREASE engine speed when making this setting, turn the potentiometer
CLOCKWISE. To DECREASE engine speed when making this setting, turn the potentiometer
COUNTERCLOCKWISE.
(c) If the governor oscillates, causing the governor-actuator linkage rod to move in an unstable
manner, adjust the GAIN control on the governor controller until the oscillation and subsequent
instability is just barely eliminated. Then re-adjust the SPEED if necessary.
(d) Upset the engine speed control lever by hand. If the lever oscillates in 3 to 5 diminishing oscil-
lations and stops, the setting is correct.
(e) Apply a load to the generator set, then remove the load and observe the length of time re-
quired for the engine speed to again stabilize. Engine speed should stabilize within 3 to 5 oscilla-
tions.
(f) If engine speed does not stabilize at the above setting, continue making slight adjustments to
the GAIN control, and checking stability and engine speed between no-load and full-load, until the
engine speed stabilizes.

(5) Re-checking Actuator Linkage

Perform this check ONLY if the engine doesn't come up to rated speed from idle speed, or
doesn't maintain rated speed under load. If either of these conditions exist, check and adjust link-
age as follows, with engine stopped.
Disconnect the ball joint from the actuator shaft clevis .
Be sure the engine speed control lever is not slipping on its shaft. If it is slipping, position it cor-
rectly and tighten it securely.
Place the engine speed control lever in FULL IDLE position and attempt to connect the ball joint
at the hole in the lever from which it was removed (Step 1) . If the holes don't align correctly,
loosen the ball joint nut and adjust the effective length of the rod assembly - shorter or longer -
and re-connect it to the actuator clevis.
Tighten the ball joint nuts securely and operate the generator set to check governor's control of
idle speed, rated at no-load speed, and full-load speed.
Repeat this procedure until generator set operates at proper speeds, with and without load.

(6) Checking the Actuator

The actuator does not require any adjustments. An actuator malfunction, when it occurs, will re-
sult in the actuator being totally inoperative, either due to the actuator coil being open or shorted
to the actuator case. Resistance measurements will reveal either of these conditions.
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December 31/91 Revised