Poblem light switch.

[peter42]

This week ive had my stairs plastered and they unscrewed the lightswitch in the hallway to plaster up to it. Im also currently having central heating installed and theyve had a circular saw chopping up floorboards in the bathroom which seems to be spagetti junction full of wires under the boards. The switch is below where he was chopping.

Last night i turned on the stair light from the downstairs switch and all the lights tripped out. i tried to reset the trip switch but it tripped immediatly. i then turned off the switch downstairs and reset the trip. I tested all other lights and there ok. I then tried the upstairs switch which operates the same light and that worked. The switch downstairs is double switch and the 2nd switch operates the hall light and that works fine.

Hope that makes sense.

So my question is wot is more likely to be the problem a faulty switch or saw cut in a cable

 

[ELZ4742]

theres a problem within the strapers....i.e, the 3core between the 2 switch's by the sounds of things. whats tripping, the whole house or just the lighting mcb?

 

[ban-all-sheds]

I then tried the upstairs switch which operates the same light and that worked.

What happens if you turn the light on that way and then use the downstairs switch to turn it off?

Are the lights on an RCD?

 

[peter42]

Its just the lighting circuit tht trips at the fuse board.

If i switch on upstairs the light works then off downstairs, it trips

 

[ELZ4742]

deffo sounds like live to earth fault on the 3core which connects between the 2 switch's.

 

[RF Lighting]

First thing to check would be for a nipped cable behind the switch plate which was removed.

 

[peter42]

Thanks for the replys,

the plate hasnt been screwed back in since since plastering, was waiting for plaster to dry. Also no wires were removed, switch was just left dangling.

 

[securespark]

Can you see any damage?

Don't poke about without turning the supply off, in case there's further unknown damage.

 

[bernardgreen]

Have the floor boards been nailed back down ? If so then my bet is there is a nail through the triple and earth shorting one of the strappers to the CPC ( earth ) conductor. Or the cable has been crushed by boards or new pipes. Or cut and bodged repair .

Only when that strapper is connected to live by the switches will the MCB trip.

 

[peter42]

The boards have been screwed back down, an electrician been round to look at wiring the boiler in and said he will come back later and try and find the fault.