T-R Controls And Components - Hobart 60CU20 Operation And Maintenance Manual With Illustrated Parts List

OM-2226 / Operation and Maintenance Manual
60CU20 / Series 500062 / 400 Hz. Generator Set

T-R Controls and Components

Trouble, Symptom,
Condition
1. Input AC and Output DC
contactor will not close
when DC OUTPUT push
button S431 is pressed.
Engine running normally,
AC voltage normal, no
load applied to output
cable.
2. Load contactor K402
opens during power
delivery. The engine is
still running at rated
speed or has returned to
idle.
May 2, 2013
Revision 2
Probable Cause
a. Defective push button switch
b. Fault code display indicates
defective contactor:
•
70.46 for input contactor
•
70.31 for output contactor
c. Defective TRB Board
a. Defective load contactor.
Fault Codes Display
•
70.46 for input contactor
•
70.31 for output contactor
b. Contactor opening could have
been normal because of an
over/under-voltage condition.
Fault Codes Display
•
70.28 for over-voltage
•
70.29 for under-voltage
c. Contactor opening could have
been normal because of an
overload or over temperature
condition.
Fault Codes Display
•
70.30 for overload
•
70.44 or 70.45 for over
temperature
d. Defective TRB Board
Test, Check, and/or Remedy
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.
Check all wire connections or replace with a
known good contactor.
If the above works correctly, see Step c.
Replace TRB board with a board known to be
operating properly. If contactor still doesn't
close, contact the factory for further
information.
Check all wire connections or replace with a
known good contactor.
If the above works correctly, see Step c.
Resume operation and closely observe
voltmeter and fault code gauge for evidence
of over/under-voltage condition. If contactor
opens and no over/under-voltage condition
exists, proceed to Step c.
Resume operation and closely observe fault
code gauge for evidence of and overload or
over temperature condition. If contactor
opens and neither condition applies, proceed
to Step d.
Replace TRB board with a board known to be
operating properly. Resume power delivery.
If contactor still opens, contact the factory for
further information.
Chapter 2-4
Page 19