Fault finding head scratcher. Discussion ThreadFault finding head scratcher. Electrical Advice
Quick drop in at a house on way home…. Customer couldn’t reset mcb for rfc.
Power off at board, outgoing cables disconnected… I was getting 200V between the neutral bar and the earth bar within the CU.
With the CU mainswitch on, I am getting a voltage on the disconnected live cables.
Have not disconnected the neutrals yet,
For now, I have left the cables disconnected, and the rest of the power on. Ran an extension lead to power the customers freezer. Will return to finish off tomorrow.
Looking at the picture below, the only other live circuit is the smoke detectors from the Wylex heating board to the right.
The rest of the heating board, and the all the off peak side of the teleswitch goes to redundant boards. It is so much more complicated than it should be.
What looks like a 3 phase head is a neutral, a live fuse, and a looped fuse which powers an advertising sign for a neighbouring hotel. Not metered, apparently.
Cross connection somewhere introducing a voltage onto the neutrals? Can only be from the smoke detector circuit.
However, this doesn’t explain the sudden cause of the breaker tripping.
Expect to find a smoking rodent in this one.
Fault finding head scratcher. for the original thread on Electricians Forums
Quick drop in at a house on way home…. Customer couldn’t reset mcb for rfc.
Power off at board, outgoing cables disconnected… I was getting 200V between the neutral bar and the earth bar within the CU.
With the CU mainswitch on, I am getting a voltage on the disconnected live cables.
Have not disconnected the neutrals yet,
For now, I have left the cables disconnected, and the rest of the power on. Ran an extension lead to power the customers freezer. Will return to finish off tomorrow.
Looking at the picture below, the only other live circuit is the smoke detectors from the Wylex heating board to the right.
The rest of the heating board, and the all the off peak side of the teleswitch goes to redundant boards. It is so much more complicated than it should be.
What looks like a 3 phase head is a neutral, a live fuse, and a looped fuse which powers an advertising sign for a neighbouring hotel. Not metered, apparently.
Cross connection somewhere introducing a voltage onto the neutrals? Can only be from the smoke detector circuit.
However, this doesn’t explain the sudden cause of the breaker tripping.
Expect to find a smoking rodent in this one.
Fault finding head scratcher. for the original thread on Electricians Forums
