Hobart 140GT17P Operation And Maintenance Manual With Illustrated Parts List page 103

TROUBLE, SYMPTOM
AND CONDITION
ENGINE AND CONTROLS (CONTINUED)
1. No (or low) gener-
ator output voltage
in all phases. Gen-
erator operating at
400 Hz in AUTOMATIC
mode.
September 30/89 Revised
PROBABLE CAUSE
A. Defective generator
or excitation circuit
B. Defective generator
Trouble Shooting Chart (Sheet 9 of 20)
Figure 4
TEST, CHECK, AND/OR
REMEDY
A. The first check is an easy
one which will allow the
mechanic to reach some
definite conclusions about
where the trouble is. Place
the AUTO-MAN switch (33,
Fig. 1) in MANUAL position.
If a normal voltage (for the
rheostat setting) is now
produced, the generator is
good, and the trouble is in
the voltage regulator cir-
cuit. Proceed to step C. If
switching to MANUAL control
did not affect generator
output, the trouble is like-
ly in the generator, but to
prove the generator is de-
fective, proceed to step B.
B. Use the test receptacle (31,
Fig. 1) to connect 12-V DC
to the exciter field. Using
leads with alligator clips
and test prods, connect 12-V
DC NEGATIVE lead to terminal
"D". Terminal identifying
letters are plainly visible
on the face of the test receptacle.
Connect POSITIVE lead to
terminal "F". If no output voltage
change is indicated when the
exciter field is energized, the gen-
erator is defective. Stop
operations and see 2-3, Para. 5
for further generator testing. If
the generator produces
approximately 140-V AC when
the exciter field is energized, the
trouble is in the voltage
regulator-excitation circuit.
Proceed to step C.
OM-2029
3-1
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