Weld Current High
Definition
The current passed through during the weld and time is too long 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 and 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