Applicable Systems
Power MIG
Symptoms
The wire feeder motor has stopped or runs at inconsistent speed. The wire does not feed smoothly and the arc stutters.
Possible Causes
- Feeder motor brushes worn down, preventing reliable motor operation
- Feeder motor speed controller board failed
- Liner clogged with dust and wire debris causing excessive drag
- Spool brake too tight, preventing the spool from feeding freely
Troubleshooting Steps
- Step 1: Check the feeder motor by removing the wire and running the feeder
If the motor runs smoothly without load, the issue is in the feed path - Step 2: Inspect and clean the liner using compressed air
Replace the liner if it is bent, crushed, or heavily contaminated - Step 3: Check the spool brake tension - the spool should unwind with slight resistance
Loosen the spool tension if the spool is tight to turn - Step 4: If the motor does not run, check the motor brushes for wear
Replace brushes shorter than 6mm; check the commutator for burning
How to Reset
Reset: The feeder resumes normal operation after the root cause is corrected.
Common Replacement Parts
- Feeder motor: 24V DC, permanent magnet (Match to feeder model)
- Motor brushes: Carbon, pair (Replace when length is below 6mm)
- Liner: Nylon or steel, match to wire size (Trim to exact length per manual)
Frequently Asked Questions
- Q: How often should I clean the liner?
Every time the wire spool is changed, or every 8 hours of welding. Blow compressed air from the contact tip end back through the liner.
- Q: What causes motor brush wear?
Continuous high-speed operation, dusty environment, and normal friction. Brushes typically last 500-1000 hours.
- Q: Can I use a steel liner for aluminum wire?
No. Use a nylon or Teflon liner for aluminum to prevent scoring and wire drag. Also use U-groove drive rolls.
Source: OEM Operation Manual
Category: Welding