Troubleshooting, Overload Protection | Lincoln Electric IM463-A

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.

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

TROUBLESHOOTING

WARNING

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.

---------------------------------------------------------------------

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.

– 19 –

Dec 95