How do I change polarity on a Lincoln Electric MIG welder?

Overview

Changing polarity is required when switching between solid wire (GMAW) and flux-cored wire (FCAW).

Steps to Change Polarity

1. Turn off the welding machine and disconnect it from the power source.

2. Open the wire drive compartment.

3. Locate the internal output terminals labeled Positive (+) and Negative (-).

4. For Solid MIG Wire (GMAW):

   • Connect the gun lead to Positive (+).

   • Connect the work clamp to Negative (-).

5. For Flux-Cored Wire (FCAW – self-shielded):

   • Connect the gun lead to Negative (-).

   • Connect the work clamp to Positive (+).

6. Tighten all terminal connections securely.

7. Close the compartment and reconnect the machine to power.

8. Perform a test weld to confirm proper arc characteristics.

Important

Incorrect polarity can result in excessive spatter, poor penetration, and unstable arc performance