Section 6 − Maintenance &Troubleshooting; Routine Maintenance; Unit Overload; Replacing Gun Contact Tip - Miller Millermatic 251 Owner's Manual

SECTION 6 − MAINTENANCE &TROUBLESHOOTING

6-1. Routine Maintenance

3 Months
Replace unreadable labels
Clean and tighten weld terminals
6 Months
Blow out or vacuum inside.

6-2. Unit Overload

Thermistor T in SCR1 protects the unit from damage due to overheating. If HL.P 002 is displayed on the meters, wait
for unit to cool allowing fan motor to run before trying to weld. If unit is cool and no weld output continues, contact
Factory Authorized Service Agent.

6-3. Replacing Gun Contact Tip

Tools Needed:
OM-1326 Page 22
Y Disconnect power
before maintaining.
Repair or replace
cracked weld cable
Remove drive roll and
carrier. Apply light coat
of oil or grease to drive
motor shaft.
OR
2
1
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.
Maintain more often
during severe conditions.
Ref. 802 990
Y Turn Off power.
1 Nozzle
2 Contact Tip
Cut off welding wire at contact tip.
Remove nozzle.
Remove contact tip and install new
contact tip. Reinstall nozzle.
Ref. 800 797-C