Power supply issue
Thread Content
Help! ! I would like to ask the experts here about a phenomenon I’m experiencing. I use a four-core cable to connect from a 380V circuit breaker (only the neutral wire is connected, no ground wire). Since the cable is too short, I use a five-core cable with an aviation plug (32A) for the connection. When I check inside the distribution cabinet, there’s a problem: when I measure the output terminal of the distribution cabinet (16A), there is a voltage of 280V between the ground wire and the live wire. There’s no problem when I use only a four-core cable to connect to the cabinet. Nor is there any issue when I use a five-core cable and connect it directly to the circuit breaker, including the ground wire. Is it because the presence of a ground wire in the five-core cable creates an interference circuit? Could someone please explain the principle behind this? Thank you.
I didn’t quite understand what the original poster meant, nor did I see any pictures; I guess it might be induced electricity? Try it with a small load first
Grounding issue. There is a potential difference between the grounding at the power supply side and the grounding at the load side.
Any unused conductors in the cable should be grounded; otherwise, induced voltage will occur.