Tweco 15XC Merlin - Manual (Page 94)

CUSTOMER/OPERATOR SERVICE 5-22 Manual 0-2251
5.11 TROUBLESHOOTING GUIDE (continued)
1. Voltage selection bus bars
connected incorrectly
2. One leg of three-phase
primary connected to
chassis ground
3. Main transformer shorted
1. Shorted input diode
(D1-D6)
2. Switching transistor (Q1)
shorted to heatsink
3. Shorted input capacitor
(C7-C12)
4. Shorted diode (D11-D14)
5. Faulty voltage selection
board
6. Faulty main contactor (W1
or W2)
1. Unit overheated
2. Faulty thermal sensor
(TS1, TS2, or TS3)
3. Faulty logic board
4. Faulty LED/current
control board
1. RUN/SET/PURGE switch
set to PURGE, secondary
mode switch set to GAS
secondary
2. Gas pressure set too low
1. Check and correct if
necessary.
2. Rewire input cable (see
Section 3.4, Electrical
Connections)
3. Replace main transformer
1. See Section 5.12-Test D
and replace diode if
necessary
2. Replace Q1, check heat-
sink for possible damage
(see Section 5.12-Test D)
3. Replace capacitor if
necessary
4. Check for proper 3-phase
power at input terminal
board, check diodes (see
Section 5.12-Test D)
5. If W1 and W2 come on
simultaneously replace
board.
6. Check and replace contac-
tor if necessary
1. Clean radiator and check
for obstruction.
2. See Section 5.12-Test E
and replace sensors if
necessary
3. See Section 5.12-Test E
and replace board if
necessary
4. See Section 5.12-Test E
and replace board if
necessary
1. Normal operation (purges
plasma line only, secon-
dary flow switch is not
satisfied)
2. Adjust pressure
SYMPTOM POSSIBLE CAUSE REMEDY
C. Fuse blown at disconnect
when primary power is
connected
D. Fuse blown at disconnect
when main contactor (W1
or W2) closes
E. TEMP indicator lit (red).
F. No GAS indicator