Help needed, very strange occurance.

[dandb]

Hello

A customer of mine called to say his fuse had blown. Nipped to his house and changed the fuse wire and it popped straight away. I advised him to unplug everything on the circuits which he did. Changed wire again and it popped again. Its a 15a rad with about 5 sockets on.

Advised circuit needs testing but might be wise to have PIR/EICR as all his circuits are labelled incorrectly and overloaded etc etc. At that moment his neighbour came round and asked if I was 'messing' with his electrics as his RCD kept tripping. I politely advised no but and asked to see fault was.

Upon carrying out the same test again every time I changed the fuse wire and put the fuse back in it tripped his neighbours RCD. I then changed the fuse wire to 30a and it didnt blow but his neighbours RCD would not come back on. I took the fuse out and the neighbours RCD went back on.

Now the house is a mid terrace, roughly 400 years old up in t' ills in macclesfield. I just dont understand why/how this would happen.

I have told my customer that obviously it needs sorting but I am now not sure to who/which property the fault will be in!?

I am bamboozled and after a rubbish day in the freezing cold fitting sockets in an outbuilding my brain will not work.

Thanks

DDB

 

[Octopus]

Oer, that certainly sounds like a fun issue to investigate.

Me thinks you need to get both homeowners to agree to a certain amount of paid investigation or you should walk away!

 

[dandb]

Oer, that certainly sounds like a fun issue to investigate.

Thanks :lol:

 

[Marvo]

Yeah that was my first thought. I wouldn't worry about the fault so much as worrying about who's paying for what. Be careful you don't end up in the middle and out of pocket.

 

[SirKit Breaker]

Has this just started to happen, or is it a problem that crops up now and again? What is the weather like in the area, I ask because damp and wet atmospheres with RCD's don't mix. if its raining as bad as it is here in Leeds, then an old house may just be weak enough to suffer with damp ingress. just a theory as i once had a very strange RCD problem caused by a leaking boiler in a cellar!. Oh and there maybe a possibility that you have 2 faults. I hop you get some better advice than i have given, but once you bottom it let us know what it was.

Cheers..........Howard

 

[Geordie Spark]

Yeah that was my first thought. I wouldn't worry about the fault so much as worrying about who's paying for what. Be careful you don't end up in the middle and out of pocket.

I agree.

Once the neighbour becomes involved in the equation things could get very messy.

 

[cablemonkey]

Would not be the first time I have heard of someone "borrowing" form next door.

 

[Marvo]

I would get both nieghbours together and explain you can't afford to be out of pocket. Get them to give you a substantial deposit in advance, at least enough to cover a couple of hours to localise the fault.

Once you've found the problem you can then quote the appropriate neighbour for the additional remedial work. By that stage they'll know how to apportion blame and they can also fight it out who's paying what for your first couple of hour between themselves.

 

[dandb]

Would not be the first time I have heard of someone "borrowing" form next door.

I have seen both incomers to the properties. Both on rods and 15mm but I must say the 'join' outside my customers house does look very 'messy'.


Thanks all for the responses. Am have asked to speak to them both.

 

[timo1]

Just a thought...I wonder what would happen if you pulled the main fuse on your customers house? that could determine if his neighbours house is being fed from your customers? I'm thinking this can only be a DNO issue? I hope the OP comes back to let us know what the problem is, I used to fear fault finding but now really enjoy it and find it gives me an odd sense of satisfaction!

 

[mogga]

IV just done a PIR on a commercial building looked for meter to find it in unit next door the one I was working on was fed from an MCD in their db but as the company I was doing work for use to own other unit they were paying for electricity for both units its been like this for approx 5 years Im so glad I had to inform them and not have anything to do with sorting out the bills it will be FUN FUN FUN

 

[Deleted member 26818]

Sounds to me as if the fault on the circuit in the customer's installation could be a high resistance fault between Line and Neutral, most likely due to damp.
Voltage from you customer's installation is then tracking through the damp to the neighbours installation's neutral, which is then causing the neigbour's RCD to operate.
Why the customer's RCD is not operating, I don't know, perhaps the neighbours RCD is 30mA and the customer's 100mA, or perhaps the neighbour's installation already has some earth leakage?

 

[GLENNSPARK]

Would not be the first time I have heard of someone "borrowing" form next door.

smells like it might just be......

 

[GLENNSPARK]

Sounds to me as if the fault on the circuit in the customer's installation could be a high resistance fault between Line and Neutral, most likely due to damp.
Voltage from you customer's installation is then tracking through the damp to the neighbours installation's neutral, which is then causing the neigbour's RCD to operate.
Why the customer's RCD is not operating, I don't know, perhaps the neighbours RCD is 30mA and the customer's 100mA, or perhaps the neighbour's installation already has some earth leakage?

offer to IR both installs (at the tails) for free...."if the RCD house" comes back good...and the "clients" house comes back poor......smell a rat..lol....

 

[dandb]

Well customer has been on saying the the neighbour wont pay for anything as there house is ok. I had to laugh and tell him to stick the fuse back in with a 30amp wire in and it wont be. Then I told him not too as that would be dangerous <wink>.
Anyway he said he is going back darn sarf for a couple of months and seeing as the house will be empty he will call me again once he is back and see what we can do. I told him the only way it seems like it can be resolved is if he pays for everything and then seeks compensation off his neighbour if that fault lies there.

Anyway thanks for all your help on this. I think I agree with Spinlondon that it could be to do with damp/passing through the properties as there is no cavity wall between.

Oh and the customer box has no RCD protection. 3036 box.