ESAB 453cc - Manual (Page 16)

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4.1 GENERAL
If this power source does not operate properly,
stop work immediately and investigate the cause of
the malfunction. Maintenance work must be per-
formed by an experienced person, and electrical
work by a trained electrician. Do not permit un-
trained persons to inspect, clean, or repair this
power source. Use only recommended replace-
ment parts.
ELECTRIC SHOCK CAN KILL! "Machinery Lockout
Procedures" should be employed. If it is not pos-
sible to use padlocks, attach a red tag to the line
disconnect switch (or fuse box) warning others
that the circuit is being worked on. Placing the
power switch in the off position does not remove all
power from inside the power source.
4.2 CLEANING
Periodically, remove the cover from the power source
and blow accumulated dust and dirt from the air pas-
sages and interior components by using clean low
pressure air. The frequency cleaning is required de-
pends upon the environment in which the power source
is used.
It is imperative that all air passages be kept as clean as
possible in order to allow adequate air flow to provide
proper cooling.
After cleaning with low pressure air, check for and
tighten any loose hardware, including all electrical
connections. Check for frayed and/or cracked insula-
tion on all power cables and replace if necessary.
Failure to replace worn or damaged cables may
result in a bare cable touching a grounded object.
The resulting electrical arc may injure unprotected
eyes and will present a serious fire hazard. Body
contact with a bare cable, connector, or conductor
may result in severe electrical shock, causing seri-
ous burns or death.
4.3 INSPECTION AND SERVICE
Keep the power source dry, free of oil and grease, and
protected at all times from damage by hot metal and
sparks.
4.3.1 Fan Motor
Keep the fan motor free of accumulated dust and dirt.
4.3.2 Transformer
Other than periodically cleaning the dust and dirt from
the transformer, no maintenance is required. Ensure
that only clean, dry, low pressure air is used.
4.3.3 Control Circuits
These circuits are protected by two 10 amp circuit
breakers mounted in the front panel. If these open, the
contactor will not operate.
4.3.4 Over Temperature Protection
If the power source reaches an abnormally high internal
temperature, the thermal protection will deenergize the
contactor circuit, shutting down the power source but
leaving the cooling fan on. After the power source has
cooled to a safe level, the thermal protection will auto-
matically reset. While deenerigized, the contactor can
not be operated.
4.3.5 Digital Voltmeter/Ammeter Calibration
To verify the accuracy of the digital voltmeter/ammeter
combination, the following procedure can be performed
periodically:
1 . Place the Panel/Remote switch in Panel position.
2. Disconnect cables from the output terminals and
then connect an accurate DC voltmeter to the
output terminals.
3. Open the front control panel by removing the two
mounting screws from the upper corners. Lo-
cate the J9 jumper plug on the control pc board
and remove the plug. The J9 jumper plug is
located just left of the meter pc board ribbon
cable connection plug J10.
4. Place the Contactor switch in the On position
5. With the primary input power on, turn the Current
control knob until you get 25V on the DC voltme-
ter. Compare the reading with the reading on the
digital voltmeter on the front panel.
6. If there is a difference in the voltage readings,
remove meter board from its four mounting
posts, and adjust the trimpot (R13) on the meter
board with a small screwdriver until the digital
meter reading matches the DC voltmeter read-
ing. When satisfied, reassemble meter board,
reconnecting J9 jumper plug, and reassemble
front control panel.
SECTION 4 MAINTENANCE