Maintenance, Routine maintenance, Filter capacitor conditioning – Lincoln Electric INVERTEC V250-S User Manual
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D-3
MAINTENANCE
D-3
ROUTINE MAINTENANCE
1.
Perform the following preventive maintenance
procedures at least once every six months. It is
good practice to keep a preventive maintenance
record; a record tag attached to the machine
works best.
2.
Remove the machine wrap-around cover and per-
form the input filter capacitor discharge procedure
(detail at the beginning of this chapter).
3.
Keeping the machine clean will result in cooler
operation and higher reliability. Be sure to clean
the following areas with a low pressure air
stream. See figure D.2 for component locations.
•
Power and control printed circuit boards
•
Power switch
•
Main transformer
•
Input rectifier
•
Heat sink fins
• Input Filter Capacitors
• Output Terminals
4. Examine capacitors for leakage or oozing. Replace
if needed.
5.
Examine the sheet metal case for dents or break-
age. Repair the case as required. Keep the case
in good condition to ensure that high voltage
parts are protected and correct spacings are
maintained. All external sheet metal screws must
be in place to assure case strength and electrical
ground continuity.
6. Check electrical ground continuity. Using an ohm-
meter, measure resistance between either output
terminal and an unpainted surface of the machine
case. (See Figure D.2 for locations.) Meter reading
should be 500,000 ohms or more. If meter reading
is less than 500,000 ohms, check for electrical
components that are not properly insulated from
the case. Correct insulation if needed.
7. Replace machine cover and screws.
FILTER CAPACITOR
CONDITIONING
A protection circuit is included to monitor the voltage
across filter capacitors C1 and C2. In the event that
the capacitor voltage is too high, the protection circuit
will prevent output. Nominal trip setting is at 230/460
VAC +15%. Reset occurs about 3% lower (230/460
VAC +12%).
On new installations, the protection circuit may also
prevent output providing all these circumstances are
met:
1.
Machine is connected for 380-415 or 440-460
VAC input.
2.
Machine did not have power applied for many
months.
3.
Machine will not produce output when power is
first switched on.
If these circumstances apply, the proper action is to
switch the machine on and let it idle for up to 30 min-
utes. This is required to condition the filter capacitors
after an extended storage time. The protection circuit
will automatically reset once the capacitor conditioning
and resultant voltage levels are acceptable. It may be
necessary to turn the power switch off and back on
again after this period.
INVERTEC V250-S