Routine Maintenance; Periodic Maintenance; Thermal Protection; Replacement Of Internal Fuse - Lincoln Electric PRO-CUT 25 Service Manual

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WARNING
ELECTRIC SHOCK
• 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 capac-
itor discharge procedure to avoid elec-
tric shock.
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ROUTINE MAINTENANCE

1. Keep the cutting or gouging area and the area
around the machine clean and free of combustible
materials. No debris should be allowed to collect
which could obstruct air flow to the machine.
2. 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: See
Figure D.2
- Printed circuit boards and heat sinks
- Power switch
3. Examine the sheet metal case for dents or break-
age. Repair the case as required. Keep the case in
good condition 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 electrical ground continu-
ity.
4. Inspect the cable periodically for any slits or punc-
ture marks in the cable jacket. Replace if neces-
sary. Check to make sure that nothing is crushing
the cable and blocking the flow of air through the
air tube inside. Also, check for kinks in the cable
periodically and relieve any so as not to restrict the
flow of air to the torch.

PERIODIC MAINTENANCE

WARNING
ELECTRIC SHOCK CAN KILL.
• Turn off machine at the disconnect
switch on the front of the machine
before tightening, cleaning or replac-
ing consumables.
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Change consumables as required.
MAINTENANCE

THERMAL PROTECTION

can kill.
Thermal Detection Devices protect the machine from
excessive operating temperatures. Excessive temper-
atures may be caused by a lack of cooling air or oper-
ating the machine beyond the duty cycle and output
rating. If excessive operating temperatures should
occur, the yellow thermal LED will light and the
Detection Devices will prevent output voltage or cur-
rent.
These Detection Devices are self-resetting once the
machine cools sufficiently. If the thermostat shutdown
was caused by excessive output or duty cycle and the
fan is operating normally, the Power Switch may be left
on and the reset should occur within a 15 minute peri-
od. If the fan is not turning or the air intake louvers
were obstructed, then the power must be switched off
and the fan problem or air obstruction must be correct-
ed.
A protection circuit is included to monitor the voltage
across filter capacitors. In the event that the capacitor
voltage is too high, the protection circuit will prevent
output.

REPLACEMENT OF INTERNAL FUSE

The PRO-CUT 25 has additional protection provided to
some circuits through an internal fuse. For replace-
ment of this fuse proceed as follows:
1.
2.
3.
4.
NOTE: If the fuse blows again after power is restored,
PRO-CUT 25
Turn off the power to the unit and remove the input
plug.
Allow the machine to stand for 5 minutes to let the
input capacitors discharge, or perform the
Capacitor Discharge Procedure after removing
the case wraparound cover.
Remove the machine cover.
Replace the blown fuse with a new 1.0A 500V
slowblow fuse.
the cause could be an internal breakdown in
the power unit. In this case, perform the trouble
shooting procedures to determine the problem.
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