Lincoln Electric INVERTEC V275-S Service Manual page 88

F-58
OUTPUT DIODES REMOVAL AND REPLACEMENT (continued)
PROCEDURE
1. Remove input power to the V275-S.
2. Using a 5/16" nut driver, remove the case wrap-
around cover.
3. Perform the Input Filter Capacitor Discharge
Procedure detailed earlier in this section.
4. Locate the output diodes. See Figure F.30.
5. Perform the Snubber Board Removal Procedure
detailed earlier in this section.
6. Using a 7/16" nut driver, disconnect leads 8X and
X1. Note washer placement upon removal. See
Figure F.31.
7. Using a 7/16" nut driver, remove heavy leads 9X
and X3. Note washer placement upon removal.
See Figure F.31.
TROUBLESHOOTING & REPAIR
(Below code 11250 only)
FIGURE F.30 - Output Diode Location
Output
Diodes
V275-S
380V
208-230V
8. Remove the allen bolt located in the center of the
output diode using a 9/64" allen wrench.
Figure F.31.
9. Using a 7/16" wrench, remove the mounting bolts
from either end of the faulty output diode.
Replace.
10. Before replacing the diode module, apply a thin
layer of Penetrox A-13 heatsink compound to the
bottom surface of the diode module. Be sure to
keep the compound away from the mounting
holes.
12. Press the module firmly against the sink while
aligning the mounting holes. Insert each outer
screw through a spring washer and then a plain
washer and into the holes. Start threading all
three screws into the heat sink (2 or 3 turns by
hand). Do not cross thread the screws.
13. Replace the mounting bolts previously removed.
Tighten bolts to between 5 and 10 inch pounds.
F-58
See