Can anyone tell me why my kemppi 3 phase mig welder has 5 wires
three of the black wires go to L1 L2 L3 then the ground and the last black wire are twisted together and are in the ground pin of a 4 pin plug
3 phase, neutral and earth = 5 cores. No neutral required so neutral and earth twisted together. (Assuming they are twisted together in the plug and the machine?)
Essentially using a 5 core cable when a 4 core cable would do.