- Reaction score
- 14
Hello All,
I've been call to a small chapel as the power goes on and off once or twice a week.
Cable is a 50mm 4C fed from a 100A 6kA MCCB 50-60m away. 4pole RCD in Chapel.
Load on each phase is about 20-35A when the A/C kicks in so MCCB and cable OK for that.
IR at 500V Fluke 1653B. Results checked on 2 meters
I pulled the cable out at both ends and did an IR test as we had a bad batch of UAE cable and very poor installation in the ground about 5-6 years ago which has now started to fail .
Results - L1 to L2, L3 N Earth over 500meg - fine
L2, L3 N and E a dead short between them all - 0.00
I had ment to do a continuity test and get a reading but was called away.
Don't worry the cables are capped off and LOTO at the MCCB.
If its a dead short how can the MCCB hold on for 3-5 days at a time before tripping, how can the MCCB ever be switched on for that matter ?
Can some one explain what I'm missing please?
I've been call to a small chapel as the power goes on and off once or twice a week.
Cable is a 50mm 4C fed from a 100A 6kA MCCB 50-60m away. 4pole RCD in Chapel.
Load on each phase is about 20-35A when the A/C kicks in so MCCB and cable OK for that.
IR at 500V Fluke 1653B. Results checked on 2 meters
I pulled the cable out at both ends and did an IR test as we had a bad batch of UAE cable and very poor installation in the ground about 5-6 years ago which has now started to fail .
Results - L1 to L2, L3 N Earth over 500meg - fine
L2, L3 N and E a dead short between them all - 0.00
I had ment to do a continuity test and get a reading but was called away.
Don't worry the cables are capped off and LOTO at the MCCB.
If its a dead short how can the MCCB hold on for 3-5 days at a time before tripping, how can the MCCB ever be switched on for that matter ?
Can some one explain what I'm missing please?