Service manual

4. Troubleshooting
4-4
4.2.2 Voltage is very high or it cannot be adjusted
4.2.3 Voltage fluctuates
NO (Higher)
Y
ES
Broken wire
NO
Check resistance in AVR
resistor hand trimmer?
Speed should be about 1,875
min
-1
for 62.5 Hz during
no-load operation.
Is AC voltage at AVR input
terminal (3-E3) proper?
A
djust the speed to
the specified speed
with the speed
adjusting bolt.
Defective resistor
HT.
Fault in AVR.
Y
ES
Repair.
NO (Very high)
Is DC voltage at AVR
connector (J-K) proper?
Y
ES
Is there any unbalance between
single-phase load phases?
Y
ES
A
re revolutions stabilized at
1,800 min
-1
?
NO
Y
ES
NO
YES (Looseness found)
NO
NO
Check whether stability of
A
VR is correctly adjusted or
not.
A
ny faulty connection found in
control panel?
Use single-phase
load by balancing it
among phases, or
increase generator
ca
p
acit
y
.
Repair / adjust
engine.
Fault in generator
winding wire.
Repair.
Repair.
Readjust.
Disconnect each connection
between generator and control
panel. And when magnetized
forcibly, the generated voltage
among phases is balanced?
NO
Y
ES
Fault in AVR.
B
Y
ES