Lincoln Electric DC-650 PRO IM463-A - Manual (Page 19)

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Power Source Troubleshooting
Most welding equipment problems, particularly in new
installations, can be traced to incorrect installation or
incorrect procedures. Be sure that the DC-650 PRO
is properly connected, all accessories and wire
feeders are working correctly, and that valid welding
procedures are being used.
TROUBLESHOOTING
ELECTRIC SHOCK can kill.
• Have a qualified individual install and
service this equipment.
• Turn the input power off at the fuse
box before working on equipment.
• Do not touch electrically hot parts.
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WARNING Routine Maintenance
1. The fan motor has sealed bearings which require
no service.
2. In extremely dusty locations, dirt may clog the air
channels causing the welder to run hot. Blow out
the machine at regular intervals.
3. In extremely dusty locations, dirt may accumulate
on the remote control terminal strip. Wipe or blow
this terminal strip off at regular intervals. This is
particularly important in damp locations
Overload Protection
The DC-650 PRO is protected from excessive output
currents by phaseback circuitry on the Control PC
board. If the output current exceeds approximately
850 amps, the output of the machine will phase back
to a low value. It will remain at a low value until the
load is removed.
If the output is shorted in one of the constant voltage
modes (GMAW, FCAW, or SAW) the output may
phase back all the way to zero. The short must be
removed from the output, and the protective circuits
reset before welding can continue. To reset them,
shut the DC-650 PRO off, and then turn it back on
again.
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