davetheglitz
Electrician
Sorry Guys - this goes on a bit!
Background
Called out today after Western Power had disconnected my elderly customers ring main after they lost power. Apparantly the 30mA RCD in the house had gone - but so had the supply to the meter. After a lot of playing around they disconnected the ring main and told the customer it was down to them. No paperwork was left - so I'm only going on hearsay concerning the fault.
On checking - no fault on the ring main. >3M insulation. Connected up - Zs at sockets around 60 ohms (TT) and no trip at 15mA - correct at 30mA.
Overall Zs all circuits in > 2M.
No outside feeds from the ring main, no signs of damp.
The house is remote - it didn't have mains electricity until 1994 and it had to come in around a mile to a local transformer.
I'm at a loss to explain the trip - unless it's something like the fridge going into defrost causing the trip. However this doesn't explain the loss of supply to the meter.
Here is the Question (at last!)
I've been told that it is feasible for a tripping fault to be caused by a fault 'upstream' from the RCD. However I can't get my head around how this could work. Has anyone found anything similar - and if so has anyone got any explanations!
Thanks
Background
Called out today after Western Power had disconnected my elderly customers ring main after they lost power. Apparantly the 30mA RCD in the house had gone - but so had the supply to the meter. After a lot of playing around they disconnected the ring main and told the customer it was down to them. No paperwork was left - so I'm only going on hearsay concerning the fault.
On checking - no fault on the ring main. >3M insulation. Connected up - Zs at sockets around 60 ohms (TT) and no trip at 15mA - correct at 30mA.
Overall Zs all circuits in > 2M.
No outside feeds from the ring main, no signs of damp.
The house is remote - it didn't have mains electricity until 1994 and it had to come in around a mile to a local transformer.
I'm at a loss to explain the trip - unless it's something like the fridge going into defrost causing the trip. However this doesn't explain the loss of supply to the meter.
Here is the Question (at last!)
I've been told that it is feasible for a tripping fault to be caused by a fault 'upstream' from the RCD. However I can't get my head around how this could work. Has anyone found anything similar - and if so has anyone got any explanations!
Thanks