Miller Electric 255 - Manual (Page 24)

OM-157 066 Page 20
4-8. Troubleshooting
Welding Trouble Remedy
No weld output; wire does not feed. Secure power cord plug in receptacle (see Section 2-12).
Reset circuit breaker CB1 (see Section 4-2).
Replace fuse F1 and/or F2 (see Section 4-3).
Replace building line fuse or reset circuit breaker if open (see Section 2-12).
Secure gun trigger plug in receptacle or repair leads, or replace trigger switch (see Section 2-7
and/or 4-7).
Thermostat TP1 open (overheating). Allow fan to run; the thermostat will close when the unit has
cooled (see Section 2-3).
No weld output; wire feeds. Connect work clamp to get good metal to metal contact.
Replace contact tip (see Section 4-5).
Low weld output. Connect unit to proper input voltage or check for low line voltage (see Section 2-12).
Wire Drive/Gun Trouble Remedy
Electrode wire feeding stops during
welding. Straighten gun cable and/or replace damaged parts (see Section 4-6).
Adjust drive roll pressure (see Section 2-13).
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 4-6).
Replace drive rolls if worn or slipping (see Section 4-4).
Secure gun trigger plug in receptacle or repair leads, or replace trigger switch (see Section 2-7
and/or 4-7).
Check and replace F1 and/or F2 (see Section 4-3).
Check and clear any restrictions at drive assembly and liner (see Section 4-6).
Have nearest Factory Authorized Service Agent check drive motor.
Check relay CR1, and replace if necessary.