September 1, 1997
P/N 401789
4 - 9
HUSSM ANN CORPORATION • BRIDGETON, M O 63044-2483 • Printed in USA
Troubleshooting—Compressor Board
(Mechanical Low Pressure Control or Series Switchback)
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
120
Go to
5
0
Failed connection between T7 and T4 – Repair
5
P1,1
T8
120
Go to
7
0
Test “ON/OFF” Switch and connections to Board –
If OK, Board Failure
6
P1,2
T8
120
Low Pressure Control closed – Go to
7
0
Low Pressure Control opened – Should be closed to
continue Board check
7
P1,3
T8
120
Go to
8
0
Board Failure
8
P1,8
T8
120
Go to
9
0
Compressor Protector open,
9
P2,2
T8
120
Go to
10
0
Board Failure
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 4-3 — Compressor Board Troubleshooting — Mechanical
Return to Contents
