Lincoln Electric 10474 Welder User Manual


 
D-1
MAINTENANCE
D-1
PRO-CUT 55
INPUT FILTER CAPACITOR
DISCHARGE PROCEDURE
1. Turn off input power or disconnect input power
lines.
2. Remove the 5/16" hex head screws from the side
and top of the machine and remove wrap-around
machine cover.
3. Be careful not to make contact with the capacitor
terminals that are located on the top and bottom of
the Power Board on the right side of the machine.
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
cap screws) on the top and bottom of the Power
P.C. Board shown in Figure D.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 the other capaci-
tor .
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.
ELECTRIC SHOCK can kill.
Have an electrician install and service
this equipment.
Turn the input power off at the fuse
box before working on equipment.
Do not touch electrically hot parts.
Prior to Performing preventative main-
tenance, perform the following capaci-
tor discharge procedure to avoid elec-
tric shock.
---------------------------------------------------------------------
WARNING
UPPER
CAPACITOR TERMINALS
LOWER
CAPACITOR
TERMINALS
INSULATED
GLOVES
INSULATED
PLIERS
POWER
RESISTOR
POWER
BOARD
RIGHT SIDE OF MACHINE
FIGURE D.1 LOCATION OF INPUT FILTER CAPACITOR TERMINALS.