Troubleshooting & repair, Warning – Lincoln Electric INVERTEC SVM129-B User Manual

Page 112

TROUBLESHOOTING & REPAIR

F-74

INVERTEC® STT® & STT® II

OUTPUT RECTIFIER REMOVAL AND REPLACEMENT (continued)

FIGURE F.39 – CHOKE LEAD/HEAT SINK CONNECTION

CHOKE LEAD

HEAT SINK TAB

PROCEDURE

1. Turn off INVERTEC® STT® & STT® II and

disconnect main AC input power to the
machine.

2. Using the 5/16" nut driver, remove the case

wraparound cover.

3. Perform the Input Filter Capacitor

Discharge Procedure. See the Maintenance
section.

ELECTRIC SHOCK can
kill.

• Before continuing with

the test procedure, per-
form the capacitor dis-
charge procedure to
avoid electric shock.

4. Using the slot head screw driver, loosen the

input cable strain relief.

5. Using the 5/16" nut driver, remove the four

screws securing the case back to the inter-
nal horizontal baffles.

6. Carefully pull the case back away from the

output rectifier assembly.

NOTE: The case back will NOT detach from

the case bottom.

7. Using the 7/16" wrench, remove the four

bolts and washers mounting the fan motor
bracket to the top horizontal baffle.
Carefully set the fan and motor assembly
aside. Note insulation placement for
reassembly.

NOTE: The fan motor leads do NOT have to

be cut.

8. Using the 7/16" wrench, remove the choke

lead from the heat sink tab. See Figure
F.39.

WARNING