Cause: Weld Current High

The current passed during the weld time is too high for the welding conditions.

Same as: Over-current condition, hot weld.

Description 

Current is too high for the combination of electrode caps in use, their condition and contact area, the weld time, the weld force, and the materials being welded.

Detection 

Detectable evidence may include:

• Cracks & holes
• Excessive indentation
• Expulsion/burn through
• Poor Class A appearance
• Sticking/stuck tips
• Brassy appearance to weld surfaces on galvanized steels
• Rapid electrode cap wear

Significance 

Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition. Special considerations are noted below:

Quality: Excessive indentation and expulsion may weaken the weld and be visually unacceptable. Expulsion can adhere to customer visible surfaces.

Workplace Issues: Expulsion forms a steel grit that contaminates weld shop equipment and paint shop processes.

Cost: Reduction in tip life may increase welding costs; Excess current use increases energy costs.

Downtime: Expulsion can accumulate (slag) and cause arcing, short-circuiting, or equipment malfunctions resulting in downtime if not resolved during preventive maintenance.

Subordinate Causes

• Nominal current set too high
• Incorrect stepper in use
• Stepper not reset after cap change/redress
• Tip contact area too small
• Wrong cap type in use