September 1, 1997
P/N 401789
4 - 11
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
Troubleshooting—Compressor Board (EPC Control)
Be sure Board Switch is closed.
Run, Refrigeration Mode
Voltmeter
Voltmeter
Action
Lead Placement
Readings
Lead 1
Lead 2
1
T7
T8
120 Go
to
2
0
Check Power Supply to Board
2
T5
T8
120
Go to
3
0
Check Power Supply to T5 from X1A
3
T6
T8
120
Go to
4
0
Alarm Circuit open – correct cause and reset
4
T4
T8
0
Go to
5
120
In Switchback - correct cause and reset
5
T3
T8
120
Go to
6
0
Check Power Supply to T3 from X1
6
T1
T8
120
Go to
7
0
Board Failure
7
T2
T8
120
Go to
8
0
EPC not calling for compressor run
8
P1,3
T8
120
Go to
9
0
Board Failure
9
P1,8
T8
120
Go to
10
0
Compressor Protector open
10
P1,5
T8
120
Go to
11
0
Check Fuse and connections – If OK, Board Failure
11
P1,6
T8
120
Go to
14
0
Alarm tripped - Go to
12
12
P1,4
T8
0
Go to
13
120
High Pressure Alarm – Correct cause and reset
13
P1,7
T8
0
Go to
14
120
Oil Alarm – Correct cause and reset
14
P2,3
T8
120
Go to
15
0
If K1 Contacts are open, correct and reset
If closed, Board Failure
15
P2,5
T8
0
Circuit Complete – End Test
120
Board Failure
Table 4-4 — Compressor Board Troubleshooting — Electronic
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