Replacing Gun Contact Tip; Troubleshooting - Miller MW225 Owner's Manual

4-5. Replacing Gun Contact Tip

Tools Needed:

4-6. Troubleshooting

Welding Trouble
No weld output; wire does not feed.
No weld output; wire feeds.
Low weld output.
Low, high, or erratic wire speed.
Wire Drive/Gun Trouble
Electrode wire feeding stops during
welding.
Secure power cord plug in receptacle (see Section 2-11).
Check and replace power switch if necessary.
Check circuit breakers CB1 and/or CB2, and reset if necessary (see Section 4-2).
Replace building line fuse or reset circuit breaker if open (see Section 2-11).
Secure gun plug in receptacle or repair leads (see Section 2-6).
Thermostat TP1 open (overheating). Allow fan to run; the thermostat will close when the unit has cooled
(see Section 2-3).
Connect work clamp to get good metal to metal contact.
Replace contact tip (see Section 4-5).
Connect unit to proper input voltage or check for low line voltage (see Section 2-11).
Readjust front panel settings (see Section 3-1).
Change to correct size drive roll (see Section 4-3).
Readjust drive roll pressure (see Section 2-12).
Replace inlet guide, contact tip, and/or liner if necessary (see Sections 2-12, and 4-4).
Straighten gun cable and/or replace damaged parts (see Section 4-4).
Adjust drive roll pressure (see Section 2-12).
Readjust hub tension (see Section 2-8).
Replace contact tip if blocked (see Section 4-5).
Clean or replace wire inlet guide or liner if dirty or plugged (see Section 4-4).
Replace drive roll if worn or slipping (see Section 4-3).
Secure gun plug in receptacle or repair leads (see Section 2-6).
Check and clear any restrictions at drive assembly and liner (see Section 4-4).
Have nearest Factory Authorized Service Agent check drive motor.
Y Turn Off unit.
1 Nozzle
2
2 Contact Tip
Cut off welding wire at contact tip.
1
Remove nozzle.
Remove contact tip and install new
contact tip. Reinstall nozzle.
Remedy
Remedy
ST-149 326-B
OM-189 482 Page 21