Lincoln Electric COMMANDER 400 SVM133-B Service Manual page 150

F-96
SCR REMOVAL AND REPLACEMENT (continued)
SPECIAL INSTRUCTIONS
NOTE: Before disassembling the existing rectifi-
er, note toward which heat sink the outer metal
ring of the power SCR is mounted. Also, note the
positioning of the gate lead of the SCR. Failure to
reinstall the new SCR in the same orientation as
the original may result in subsequent damage to
the new SCR and other components of the
welder. See Figure F.43.
TROUBLESHOOTING & REPAIR
FIGURE F.43 – SCR DETAILS
COMMANDER 400
CAUTION
The unclamping and clamping procedure outlined
below is critical for the prevention of internal SCR
damage. Failure to follow this procedure may
result in subsequent damage of the SCR. Handle
all SCRs with care.
F-96