Cause: Wrong Cables/Shunts
The weld is not correctly made due to the use of an incorrect cable or shunt.
Description
Cross Sectional Area:
- Too small: Current flow is restricted due to the increase in impedance.
- Too large: Conductor stiffness can cause problems in properly locating equipment; premature wear to the machine components; or achieving weld force.
Conductor Length:
- Too long: Current flow is restricted due to the increase in impedance; proper weld placement can be hindered by cable drag and entanglement; short circuits may result from the above conditions.
- Too short: Inadequate length can cause problems in properly locating equipment; premature wear to machine components; or achieving required weld force.
Detection
Detection evidence may include:
- Inconsistent weld quality
- Mislocated/edge weld
- Missing weld
- Non-round weld
- Poor Class A appearance
- Sheet metal distortion
- Sticking/stuck tips
- Stuck weld
- Undersized weld
- Burns and sparks on equipment suggesting short circuits
- Excessive manual effort to position equipment
Significance
Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition. Special considerations are noted below:
Quality: Cables that are improperly sized can cause variations in welds from operator to operator in manual operations.
Subordinate Causes
- Correct conductor not immediately available
- Increase in jobs per hour, weld current, or weld time requirements
