Troubleshooting & repair – Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B User Manual

Page 253

F-193

FET MODULE REMOVAL AND REPLACEMENT

(continued)

FIGURE F.74 - LIFT BAFFLE/BAIL REMOVAL

TROUBLESHOOTING & REPAIR

9. With the wire cutters, cut all necessary

cable ties.

10. Disconnect the leads to the output rectifi-

er bridge. Cut all necessary cable ties.

11. Disconnect two plugs from the snubber

board.

12. Disconnect the output cable strap and pull

it through and free from the lift bail baffle
eyelet hole. Cut any necessary cable ties.

13. With the 3/8" nut driver, remove the two

screws that hold the lift bail baffle. See
Figure F.74. Remove the baffle.

14. With the 1/2" socket wrench, remove the

four bolts (two on each side of the
machine) from the lift bail. See Figure
F.74. Slide the lift bail up and free of the
machine.

15. On the right side of the machine, cut any

necessary cable ties to free the wiring har-
ness from the subframe.

16. With the Phillips head screw driver,

remove the screw that holds the piezo-
electric alarm buzzer in place. Cut the
cable tie that holds the wire.

17. With the 3/8" wrench, remove the six

resistors that are attached to the top of the
subframe (four on the top right, two on the
top left). Note the physical placement and
wiring for reassembly; labeling is recom-
mended. Also loosen the bottom resistors
closest to the FET module assembly. This
will allow the capacitors to clear the resis-
tors when the FET module assembly
slides forward for removal.

18. With the 5/16" nut driver, remove the

sheet metal screw holding the ground
leads to the right rear of the subframe. On
the left side, unclip the cable tie holding
the leads. Let the back of the subframe
swing out carefully; the harness will sup-
port it.

19. With the 5/16" wrench, remove the two

sheet metal screws holding the subframe
bottom support section. Note the green
ground lead on the left side; be sure to
reconnect it during reassembly.

20. With the 7/16" wrench, disconnect the

heavy current-carrying flat copper strap
running from the shunt amplifier to the
output rectifier bridge.

POWER WAVE 450