28.5 VDC Ground Power Unit
Models:
11A6647-1000/1010
11B6647-1000/1010
11C6647-1000/1010
11D6647-1000/1010
11A6647C1000/1010
11B6647C1000/1010
11C6647C1000/1010
11D6647C1000/1010
11A6655-1000/1020
11B6655-1000/1020
11C6655-1000/1020
11A6655C1000/1020
11B6655C1000/1020
11C6655C1000/1020
11D6655C1000/1020
11A6665-1000/1010
11B6665-1000/1010
11C6665-1000/1010
11A6666-1000
11B6666-1000
11C6666-1000
12/2006 - Rev. 04
- 48 -
6.3
MONITORS & FAULT INDICATION (continued)
Event Number
LED Status
Test or Inspection
Corrective Action
*557
Phase Rotation
Failure Input
1. Inspect input power cables for
incorrect phase connection
1. Correct incorrect phase
connections
*560
Temperature
Failure Rectifier
1. Check for blocked air inlet
2. Verify that the unit has not been
operating in an overload condition
for an extended period of time.
1. Clean all air inlets and screens
2. Allow rectifier to cool down and
then operate it with less load.
*561
K1 Failure
1. Check the K1 coil
2. Check the K1 auxiliary contact and
wiring
1. Replace the coil if it is defective
2. Fix the wiring or replace the
auxiliary contact if needed
*565
Output Voltage
High
1. Check wiring for output voltage
measurement at board A100
2. Check for faulty static switch
thyristors V001 – V003 and firing
board A010
1. fix the wiring
2. Replace firing board A010 or faulty
thyristors V001 – V003
*566
Output Voltage
Low
1. Check for a faulty static switch
thyrisotrs V001 – V003 and firing
board A010
2. Check for faulty transformer or
rectifier
1. Replace firing board A010 or faulty
thyristors V001 – V003
2. Replace transformer or rectifier
*572
Temperature
Failure
Internal/Static
Switch
1. Check the air filters (optional) and
screens for blockage
1. 1. Clean the filters and screens.
Wait for the unit to cool down
before restarting
*581
Overload Output
1. Check the maximum load on the
unit and make sure that it doesn’t
exceed 400 A (at the 400A unit) or
600A (at the 600A unit) resistive
load
1. Lower the total load on the unit
No LED’s lit and
the Control Panel
display is Off
1. Verify input power is available
2. Check Q100 circuit breaker
1. Restore input power to the unit
2. Reset tripped circuit breakers