Lincoln Electric IM467 SQUARE WAVE TIG 355 - Manual (Page 37)

MAINTENANCE
D-1 D-1
SQUARE WAVE TIG 355
WARNING
SAFETY PRECAUTIONS
• Only Qualified personnel should
perform this maintenance.
• Turn the input power OFF at the
disconnect switch or fuse box
before working on this equipment.
• Do not touch electrically hot parts.
INPUT POWER FACTOR
CAPACITOR DISCHARGE
PROCEDURE
This procedure ensures that the power factor capaci-
tors are discharged, for greater safety when you are
working on the Square Wave TIG 355 with INPUT
POWER REMOVED.
1. Remove input power to the machine.
2. With a 5/16" nut driver, remove the sheet metal
screws that hold the right case side in place.
Remove the right case side.
3. With a volt/ohmmeter, carefully check the voltage
across the input power factor capacitors. When
input power is removed, the voltage across each
capacitor should be zero. (Normally, the capaci-
tors discharge through the primary winding in the
main transformer.)
4. If capacitor voltage is zero, you may begin working
on the Square Wave TIG 355.