Lincoln Electric IDEALARC IM402-B - Manual (Page 13)

MAINTENANCE
Safety Precautions
General Maintenance
1. The fan motor has sealed ball bearings which
requires no service.
2. In dusty locations dirt may clog the air channels
causing the welder to run hot. Under these
conditions carefully blow out the welder at regular
intervals.
3. Keep the electrode and work cable connection
tight.
4. Every twelve months or at the first indication of a
binding current pointer, turn the input power off
and remove the left case side. Wipe the pointer
guide bar clean and lubricate with graphite
grease.
5. When cleaning the current pointer, clean the
reactor quadrant teeth, drive gear and pinion.
Lubricate with graphite grease.
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TROUBLESHOOTING
Safety Precautions
Rectifier Troubleshooting
1. Turn the input power off.
2. Disconnect all input and output leads from the
rectifier bridge.
3. Connect an ohmmeter between the DC positive
(red) terminal and one of the AC (yellow) termi-
nals. Note the ohmmeter reading using the 10 to
100 scale.
4. Reverse the ohmmeter leads. Note the readings.
5. The reading taken in steps 3 and 4 should be
different. If the readings are the same and
near zero, the rectifier has shorted. IF the
readings are the same and near full scale, the
rectifier has failed open.
6. Repeat steps 3, 4 and 5 between the DC posi-
tive (red) terminal and each of the AC (yellow)
terminals.
7. Repeat steps 3, 4 and 5 between the DC nega-
tive (black) terminal and each of the AC (yel-
low) terminals.
NOTE: Since it is unlikely that all rectifiers of a
full wave bridge would fail simultaneously,
check the test method and the ohmmeter if the
checking indicates that all rectifiers have failed.
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
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