Hobart 9OC24S Operation Manual page 185

GENERATOR DIVISION
HOBART BROTHERS COMPANY
OPERATION, MA'IN TENANCE , AND OVERHA.UL MANUAL, TM-240A
SELF-PROPELLED GENERATOR SET, SPEC. NO. 5381A
(4) Electric control box adjustment
Before making an adjustment to the control box, make certain the linkage
between the actuator (1, Fig. 9) and fuel control lever (8) is free and that
there is no backlash, "play", or lost motion in the linkage. Be sure the
magnetic pickup is producing a strong, norma I output.
Be sure adequate
fuel oil pressure is reaching the actuator and that the actuator is properly
adjusted.
Th e actuator servo piston must be free and not sticking. Ad-
just control box as fol lows:
NOTE: Remove LEFT access cover on the canopy and LEFT access
cover on the engine-generator control box to gain access
to the electric governor control box which is mounted inside
the main control box (see Fig. 1).
(a) Start engine and allow it to warm.
(b) Accelerate engine to governed speed by placing the operating mode
switch in GEN position.
(c) Use the adjusting screw in the speed-setting potentiometer (Fig. 12)
to adjust engine speed to produce a generator output of exactly 400 Hz
(2400 R PM).
NOTE: 1. A very small screwdriver is required for this adjustment.
Turn the screw CLOCKWISE to IN aEASE engine speed,
and COUNTERCLOCKWISE to DECREASEspeed.
2. This is a 24-turn potentiometer with no stops. The adjusting
screw is designed to slip when the wiper reaches the end of
its travel in either direction.
(d) With the engine running smoothly at governed speed (400 Hz), manually
force the actuator lever to an "under-speed" position momentarily to
simulate a sudden loaded condition. The actuator should act immediately
to bring the engine up to governed speed without surging.
If actuator
action is slow or if surging is present, adjust the "gain" and "reset-droop"
potentiometers per step (e).
(e) Loosen locknuts. Set both the "gain" and "reset-droop" screws at mid-
range (no. 5 on the scale). Turn the "gain" adjusting screw slowly clock-
wise until engine operation becomes slightly unstable (surges).
N OTE : It may be necessary to manual ly force the actuator lever to an
underspeed position momentarily to initiate surging.
2-3
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