Troubleshooting & repair, Scr output bridge replacement – Lincoln Electric IDEALARC DC 1000 SVM123-A User Manual
Page 90
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TROUBLESHOOTING & REPAIR
SCR OUTPUT BRIDGE
REMOVAL
1.
Remove input power to machine.
2.
Using a 5/16 (8mm) nut driver or flat
head screw driver, remove 20
screws (ten per side) to remove
case sides and 2 screws to remove
top.
3.
Using a 5/16 (8mm) nut driver or flat
head screw driver, remove 6
screws, then lower the front control
panel.
4.
Remove the J4 gate lead Molex
plug from firing board, and feed the
plug down through the hole in bot-
tom of the PC board compartment.
5.
Using a 9/16” socket and open-end
wrench, remove the two bolts and
nuts holding the shunt assembly to
the two positive buss leads con-
nected to the SCR bridge. See
Figure F.22.
6.
Using a 5/16” socket remove the
screw and small reed switch lead
(#210) from the left, top rear SCR
heat sink.
NOTE: It may be necessary to move or
remove the output choke to gain access
to the bottom anode leads. For access
to the bottom middle screw, nut, and
associated washers, a long handled flat
ratchet is recommended.
7.
Identify and label the six trans-
former secondary (heavy alu-
minum) leads that connect to the
anodes of the SCR heat sink
assemblies. Using a 1/2” socket
and open-end wrench, remove the
secondary leads (see Figure F.22).
8.
Support the SCR bridge assembly
with a lift hook or rope.
9.
Using a 3/8” socket wrench,
remove the two screws (one on
each side) holding the SCR assem-
bly rails to the front panel assem-
bly.
IDEALARC DC-1000
FIGURE F.22 - Preparation For SCR Output Bridge Removal
SCR OUTPUT BRIDGE REPLACEMENT
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