OM-2245 / Operation and Maintenance Manual
ITW GSE 4400 / 400 Hz. Generator Set
March 15, 2015
Chapter 2-4
Page 12
Load Contactor Operating Circuit (Continued)
Trouble, Symptom, Condition
Probable Cause
Test, Check, and/or Remedy
2.
Load contactor closes when
the
Output
pushbutton is
pressed, but opens within 10
seconds.
a.
The plug interlock EF circuit on
Interface board could be
defective.
Set 400 Hz Interlock to Bypassed.
If load contactor remains closed,
proceed to step
b.
b.
28.5 VDC is not reaching the plug
interlock EF circuit from aircraft
for following reasons:
Proceed as follows to find the
cause of this malfunction.
c.
Generator-to-aircraft cable
connector defective or not
plugged into aircraft receptacle
connector
Inspect cable connector plug
thoroughly for damaged E and F
terminals. Be sure plug is fully
mated with aircraft receptacle
connector and making good
contact.
d.
Aircraft rejecting power.
Check aircraft on-board electrical
equipment and controls.
e.
Defective contacts in switch
mounted on side of contactor.
Connect a jumper lead between
terminals of the normally-open
auxiliary switch. If the contactor
now remains closed, replace the
auxiliary switch or the entire
contactor.
