Input Filter Capacitor Discharge Procedure; Routine Maintenance - Lincoln Electric INVERTEC V350-PRO SVM152-A Service Manual

D-2
WARNING
Have qualified personnel do the maintenance
work. Always use the greatest care when
working near moving parts.
Do not put your hands near the cooling blower
fan. If a problem cannot be corrected by
following the instructions, take the machine to
the nearest Lincoln Field Service Shop.
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ELECTRIC SHOCK can kill.
• Do not touch electrically live parts or
electrode with skin or wet clothing.
• Insulate yourself from work and
ground
• Always wear dry insulating gloves.
------------------------------------------------------------------------
EXPLODING PARTS can cause
injury.
• Failed parts can explode or cause other
parts to explode when power is applied.
• Always wear a face shield and long sleeves when ser-
vicing.
------------------------------------------------------------------------
See additional warning information
throughout this operators manual.
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INPUT FILTER CAPACITOR
DISCHARGE PROCEDURE
1. Remove the input power to the V350-PRO.
2. Using the 5/16" wrench remove the screws from
the case wraparound cover.
3. Be careful not to make contact with the capacitor
terminals located at the top and bottom of the
switch board.
4. Obtain a high resistance and high wattage resis-
tor (25-1000 ohms and 25 watts minimum). This
resistor is not with the machine. NEVER USE A
SHORTING STRAP FOR THIS PROCEDURE.
MAINTENANCE
FIGURE D.1 — LOCATION OF INPUT FILTER
RESISTOR
5. Locate the eight capacitor terminals shown in fig-
ure D.1.
6. Using electrically insulated gloves and pliers, hold
the body of the resistor with the pliers and connect
the resistor leads across the two capacitor termi-
nals. Hold the resistor in place for 10 seconds.
DO NOT TOUCH CAPACITOR TERMINALS WITH
YOUR BARE HANDS.
7. Repeat the discharge procedure for the other
three capacitors.
8. Check the voltage across the terminals of all
capacitors with a DC voltmeter. Polarity of the
capacitor terminals is marked on the PC board
above the terminals. Voltage should be zero. If
any voltage remains, repeat this capacitor dis-
charge procedure.

ROUTINE MAINTENANCE

1. Every 6 months or so the machine should be
cleaned with a low pressure airstream. Keeping the
machine clean will result in cooler operation and
higher reliability. Be sure to clean these areas:
• All printed circuit boards
• Power switch
• Main transformer
• Input rectifier
• Auxiliary Transformer
• Reconnect Switch Area
2. Examine the sheet metal case for dents or breakage.
Repair the case as required. Keep the case in good con-
dition to insure that high voltage parts are protected and
correct spacings are maintained. All external sheet metal
screws must be in place to insure case strength and elec-
trical ground continuity.
V350-PRO
CAPACITOR TERMINALS
EIGHT
CAPACITOR
TERMINALS
- + - +
- +
- +
INSULATED
POWER
D-2
INSULATED
PLIERS
GLOVES