No. 1 Load Contactor Operating Circuit - Hobart 60CU24 Operation And Maintenance Manual With Illustrated Parts List

OM-2098C / Operation and Maintenance Manual
60CU24 / Series 500060C / 400 Hz. Generator Set
Trouble, Symptom, Condition
Generator Excitation Circuits (continued)
1. No (or low) generator output
voltage in all phases. Generator
operating at 400 Hz. (continued).
Trouble, Symptom, Condition

No. 1 Load Contactor Operating Circuit

1. Load contactor (K1) will not
close when output No. 1 push
button switch is held in close
position. Generator running at
normal voltage. Rectifier circuit
breaker CB2 closed. No fault
indicated
April 01, 2005
Probable Cause
e. Defective connector at voltage
regulator, or defective wiring from
regulator to exciter field
Probable Cause
a. Defective circuit breaker (CB2).
b. In addition to defective wiring
and connections in AC and DC
load contactor actuating circuits,
load contactor may be prevented
from closing for any one of
following reasons:
c. Defective REG board.
d. Defective output No. 1 push
button switch (S75).
e. Defective voltage regulator
(REG).
Test, Check, and/or Remedy
Disconnect exciter wires at
terminal strip. Using jumper leads
with clip terminals, connect 12
VDC to wires. If generator will
produce at least 80 V-AC, replace
or repair connector and wiring
between voltage regulator and
exciter field as required.
Test, Check, and/or Remedy
Remove terminal leads from circuit
breaker, press circuit breaker
button to close circuit breaker, and
use an ohmmeter. Replace circuit
breaker if defective.
Check all wiring and connections
in load contactor circuits.
Replace REG board with a board
known to be operating properly. If
contactor still doesn't close,
proceed to step d.
At rated speed, measure the
voltage across the switch. The
voltage should read approximately
5 VDC. Press the switch again
and the voltage should go to 0 V.
If voltage does not go to 0 V, the
switch is defective and needs to
be replaced.
After making certain that output
No. 1 push button switch (S75) is
working, measure DC output
voltage at contactor coil. If voltage
measured isn't approximately 90-V
DC, replace REG.
Chapter 2-4
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