Troubleshooting & repair, Input filter capacitor discharge procedure – Lincoln Electric INVERTEC SVM101-B User Manual

Page 42

V300-I

TROUBLESHOOTING & REPAIR

INPUT FILTER CAPACITOR
DISCHARGE PROCEDURE

1. Turn off input power or disconnect input power

lines.

2. Remove 14 5/16” hex head screws from side and

top of machine (6 screws on each side and 2
screws on top) and remove wrap-around machine
cover.

3. Be careful not to make contact with the capacitor

terminals that are located in the center of the Switch
Boards.

4. Obtain a high resistance and high wattage resistor

(25-1000 ohms and 25 watts minimum). This resis-
tor is not supplied with machine. NEVER USE A
SHORTING STRAP FOR THIS PROCEDURE.

5. Locate the two capacitor terminals (large hex head

capscrews)shown in Figure F.1.

6. Use electrically insulated gloves and insulated pli-

ers. Hold body of the resistor and connect resistor
leads across the two capacitor terminals. Hold
resistor in place for 10 seconds. DO NOT TOUCH
CAPACITOR TERMINALS WITH YOUR BARE
HANDS.

7. Repeat discharge procedure for capacitor on other

side of machine. If you are working on a 575 VAC
machine, repeat discharge procedure for second
capacitor on each side of machine.

8. Check voltage across terminals of all capacitors

with a DC voltmeter. Polarity of capacitor terminals
is marked on PC board above terminals. Voltage
should be zero. If any voltage remains, repeat this
capacitor discharge procedure.

F-12