Lincoln Electric POWER WAVE SVM135-B Service Manual page 155

F-91
OUTPUT RECTIFIER AND MODULE REMOVAL AND REPLACEMENT (continued)
RECTIFIER MODULE REMOVAL
AND REPLACEMENT
PROCEDURE
1. Using the 9/64 in. Allen wrench,
remove the cap screw from the center
of the rectifier module that is to be
replaced.
2. Using the 7/16 in. wrench, remove the
two mounting bolts and associated
washers from the rectifier module to be
replaced.
3. Remove the faulty module.
4. This module requires special mounting
considerations to prevent warping of
the base plate. The heatsink surfaces
must be clean and flat. Apply a thin,
even coating of thermal compound,
(Penetrox A13) 0.004 to 0.010 inches
thick. Keep the compound away from
the area of the mounting holes.
5. Press the new module firmly against
the heatsink while aligning the mount-
ing holes. Start all three screws two to
three turns by hand.
6. Tighten each of the outer screws to
between 5 and 10 in/lbs.
7. Tighten the center screw to between 12
and 18 in/lbs.
8. Tighten each of the outer screws again,
this time to between 30 and 40 in/lbs.
TROUBLESHOOTING AND REPAIR
POWER WAVE 455/POWER FEED 10
RECTIFIER ASSEMBLY
REPLACEMENT PROCEDURE
1. Position the assembly in place with the
mounting bolts.
2. Assemble the nuts and associated
washers to the mounting bolts.
3. Using the 7/16 in. wrench, tighten the
four nuts on the mounting bolts.
4. Replace leads #220 and #290 to the
thermostat.
5. Connect the eight transformer leads to
the correct rectifier modules. Tighten
the screws (with two flat washers and
one lock washer) to between 30 and 40
in/lbs. Do not stress the terminals
when making these connections.
6. Apply a thin coat of Penetrox A13 to the
heatsink where the positive output lead
attaches.
7. Attach the positive output lead to the
heatsink using the 9/16 in. wrench.
8. Install the case top and sides using the
3/8 in. nutdriver.
F-91