Tripping oddness

[crompton]

Hello Sparkies,
I've got a problem that's beyond my pay grade.
The power tripped, I checked, the RCD had tripped. After trying and failing to reset, I turned all toggles on the main board off, turned on the main switch, then the RCD, then all the others in turn.
Isolated it to upstairs sockets.
Tried immersion & shower pump first - thinking water problem. No.
Now all upstairs sockets switched off but still tripping.
Any suggestions?

Thanks,

 

[ricicle]

Is everything actually unplugged (some sockets leave the neutral in circuit) Are there any hidden things you have forgotten (boiler ?) on Fused connection units.

Failing any obvious problem with appliances the it is possibly a fault on the fixed wiring. Neutral to earth problems are usually the hardest to find and require competance to find.

 

[Alarm]

Unplug everything, then put them back one at a time.

Have someone downstairs, when it trips they shout.

 

[crompton]

thanks
no I hadn't unplugged, just turned the sockets off.
I'll hop to it.
Nice relaxing fathers' day.
Better turn the PC off first too. They don't like it when you whip the leccie out from under them, do they.

 

[markcromp]

No luck.
All the sockets are unplugged.
Went back down in the cellar, flicked the toggle, about 4-5 seconds (just enough time to give you false hope)
and the RCD trips again.
When the upstairs socket toggle is down/off, everything else works fine.
Any suggestions?

 

[markcromp]

Are there any hidden things you have forgotten (boiler ?) on Fused connection units.

Should I turn the boiler off? It's in the kitchen and has its own toggle on the board.
But there is some funny wiring that goes alongside the HW pipe back up to the immersion, don't ask me why.
Thanks again.

 

[EFLImpudence]

about 4-5 seconds

This would make me think it was an appliance rather than wiring, although still could be.
Are you sure you haven't forgotten something - in loft - exterior lighting?

Turn off boiler if covered by this RCD.

Had same problem at customer's once then found extension lead under a bed.

 

[markcromp]

Every socket turned off with no appliances plugged in.
There is a CH toggle on the main board. I turned off that and the boiler. Apart from lighting all that's left upstairs are two switches, on immersion heater, one shower pump. Both turned off.
Still trips.
V. puzzling.

 

[EFLImpudence]

It would appear that you need an electrician with proper testing equipment.

The fault is likely a connection between Neutral and Earth (CPC) on the upstairs Socket circuit. Very difficult to find without equipment.

 

[xr4x4]

Apart from unscrewing the socket fronts and checking wiring and connections.

 

[markcromp]

ok so no solution today, bring in the sparky.
But at least I know what to tell him, so thanks for all the advice chaps.

 

[markcromp]

Another thought,
I've been in this house for 7 years and this hasn't happened before, so presumably all the wiring and connections are pukka, so something must have changed at the point it started tripping, and I'm pretty sure we don't have mice having a go at the insulation.
Also, is it easy to check power leaking to earth or whatever when I can't get power to the circuit - because of the original problem: tripping.
Probably a real 'D'Oh!' question, but I'm not the sparky sorry.

ta

 

[333rocky333]

Also, is it easy to check power leaking to earth or whatever when I can't get power to the circuit -

The electrician would use an "Insulation tester" this has an internal battery so produces its own power capable to test.

He wouldnt really be measuring leakage to earth, more test the insulation resistance to see if it is preventing any such leakage of current to earth.
He could use a low amp clampmeter to measure the current to earth, but unlikely in your case i would have thought.