Cause: Wrong Cables/Shunts

Definition
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.

• 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/ddge weld
• Missing weld
• Nonround 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.