Electrical Question - Earth trip after power cut
Electrical Question - Earth trip after power cut
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Discussion

cramman

Original Poster:

659 posts

211 months

Thursday 2nd July 2009
quotequote all
Question for anyone who knows more than me about house electrics.

Yesterday we had a power cut, very brief, caused by a lightning strike. When I got in from work, although the power was back on, my circuit breaker had broke causing everything to trip.
The earth leakage had popped and wouldn’t reset until I had turned everything off. Once back on it’s been fine.
My question is, why did the earth leakage go? It’s relatively new and is sensitive, which is a good thing; just I’d rather a power cut didn’t do it. Fridge off etc, not ideal if I was away.

My thoughts were, was my house struck? No sign of damage so I’m doubtful on that one.
Possibly a poor earth? Old flat, earthed through an earth spike, water pipe and gas main.

Cheers,

Cramman.

esselte

14,626 posts

283 months

Thursday 2nd July 2009
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Probably everything coming back on at the same time (when power was restored) caused a current surge?

eddie1980

419 posts

204 months

Thursday 2nd July 2009
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When you say everything was tripped I assume you mean the RCD was tripped not the MCB?

cramman

Original Poster:

659 posts

211 months

Thursday 2nd July 2009
quotequote all
Correct. It's the rcd, not the big main fuse. Just the one that trips everything but can be turned on with the flick of a switch.

I like the idea of everything turning itself back on causing a surge, if that happens that is.

Edited by cramman on Thursday 2nd July 20:27

x type

959 posts

206 months

Thursday 2nd July 2009
quotequote all
we get many calls in work for off supply after lightning
9/10 are trip switches ,something to do with the eart electrode outside picking up stray vlotage from the lightning


cazzer

8,883 posts

264 months

Thursday 2nd July 2009
quotequote all
Any ideas why my earth leakage breaker goes repeatedly for about a week...then is fine for months....then has another week of going off evey 15 minutes?

cramman

Original Poster:

659 posts

211 months

Friday 3rd July 2009
quotequote all
x type said:
we get many calls in work for off supply after lightning
9/10 are trip switches ,something to do with the eart electrode outside picking up stray vlotage from the lightning
This could be the case, the strike which actually caused the power cur was within a mile of the house.
Cheers, think I'll check my earths anyway, won't do any harm.

cazzer said:
Any ideas why my earth leakage breaker goes repeatedly for about a week...then is fine for months....then has another week of going off evey 15 minutes?/quote]

I'd suggest you have a problem that is worth checking out. I had a similar problem and found out one of my earth, in a socket, was loose. It doesn't take allot to trip these boards, you can get a thing for checking sockets, no idea how much tho, I just borrow one from the old man. May be worth having a wander around with one of those.

x type

959 posts

206 months

Friday 3rd July 2009
quotequote all
cazzer said:
Any ideas why my earth leakage breaker goes repeatedly for about a week...then is fine for months....then has another week of going off evey 15 minutes?
this type of problem is a nightmare to find ,it could be anything in the house starting to play up
only chance you may have is when it's tripping constantly unplug (not just switch off) appliances 1 by 1 until maybe it stops

We've had a few problems recently with the multi socket adapters for computers with surge protection breaking down .

We've also had 1 customer whose trip had been going off randomly for almost 20 years !!!!!

She'd had numerous people to check her system with no problem found we changed her supply cables and even chnged the transformer feeding her , still the trip went off whenever it wanted to

she was threatning legal action and going to the press etc. she reckoned the mains were causing it somehow

Happened to be talking to her about it one day and she said " it's been happening ever since I bought the freezer for the garage 20 yrs ago "

Told her to ditch it for a few weeks and let me know what happens

Never heard from her for almost a year until we did a job next door ,asked about the tripping

She sheepishly replied ,no problems since getting rid of that freezer

cazzer

8,883 posts

264 months

Saturday 4th July 2009
quotequote all
x type said:
cazzer said:
Any ideas why my earth leakage breaker goes repeatedly for about a week...then is fine for months....then has another week of going off evey 15 minutes?
this type of problem is a nightmare to find ,it could be anything in the house starting to play up
only chance you may have is when it's tripping constantly unplug (not just switch off) appliances 1 by 1 until maybe it stops

We've had a few problems recently with the multi socket adapters for computers with surge protection breaking down .

We've also had 1 customer whose trip had been going off randomly for almost 20 years !!!!!

She'd had numerous people to check her system with no problem found we changed her supply cables and even chnged the transformer feeding her , still the trip went off whenever it wanted to

she was threatning legal action and going to the press etc. she reckoned the mains were causing it somehow

Happened to be talking to her about it one day and she said " it's been happening ever since I bought the freezer for the garage 20 yrs ago "

Told her to ditch it for a few weeks and let me know what happens

Never heard from her for almost a year until we did a job next door ,asked about the tripping

She sheepishly replied ,no problems since getting rid of that freezer
Have pretty much been through that process.
Everytime we think we've worked out what device/plug socket/lightswitch it is and stop using it, it happens again a few weeks later.
It never seems to be what we thought last time.