Cold weather and electrics...

[zaarin_2003]

Hi,

We just had what we thought was a power cut. All the electrics cut out, until we realised it was the main circuit breaker on the RCD which had tripped. None of the individual circuit breakers had tripped, just the main.

I turned them all off again, flipped the main breaker on, and then one by one switched the circuits on. The main breaker tripped when the circuit marked 'upstairs lights' was switched on, indicating a fault with that circuit.

This has happened once about 2 years ago, when terrible stormy weather caused a leak which passed through one of our loft extension light sockets and tripped that circuit. The problem stopped when the weather stopped and the light dried out and we've never had such bad weather again. This time, we have not had any significant rain or wind for days.

But what we have had, is really, really cold weather (-7 at night). Our car doors have been frozen shut, the outside tap is frozen inside, that sort of thing. I mean, it's warming up during this afternoon, but could the cold weather have caused this?

Or could it more likely be something else?

Thanks

Matt

 

[oldbutnotdead]

I'm assuming here it was an RCD that popped (it'll be labelled as an RCD and have a TEST button on it).
Good odds you've got some damp or condensation in a fitting or cable somewhere (remember outside lights, aerial distribution amps) and it's frozen creating a path from N or L to E.

 

[JohnD]

Have you gone in the loft and looked for signs of damp, such as condensation?

This is the time of year for it

CONDENSATION IN LOFT (ANSWERS)

This seems to be the time of year for condensation in lofts, so instead of replying to lots of queries I though I would write this "one-size-fits-all" post. Please also see //www.diynot.com/wiki/Building%3ACondensation-in-Houses Condensation in lofts occurs when the amount of water...

www.diynot.com

 

[zaarin_2003]

I'm assuming here it was an RCD that popped (it'll be labelled as an RCD and have a TEST button on it).
Good odds you've got some damp or condensation in a fitting or cable somewhere (remember outside lights, aerial distribution amps) and it's frozen creating a path from N or L to E.

Yes, it was on the RCD. I have edited the post to reflect that.

 

[zaarin_2003]

Have you gone in the loft and looked for signs of damp, such as condensation?

This is the time of year for it

CONDENSATION IN LOFT (ANSWERS)

This seems to be the time of year for condensation in lofts, so instead of replying to lots of queries I though I would write this "one-size-fits-all" post. Please also see //www.diynot.com/wiki/Building%3ACondensation-in-Houses Condensation in lofts occurs when the amount of water...

www.diynot.com

We have a loft extension, so yes, we sleep in there! But no, I can't see any visible water dripping or damp etc.

 

[terryplumb]

Got any external lights ?

 

[JohnD]

Perhaps the loft conversion has ceiling lights.

 

[zaarin_2003]

Perhaps the loft conversion has ceiling lights.

That's right, it does. In the past one of the ceiling lights dripped water and that was the issue I mentioned from two years ago in the opening post. But today I see no issues.

 

[zaarin_2003]

Got any external lights ?

Yes, two and actually one of them is brand new. I don't know if they are on the relevant circuit though, they don't activate until it's dark.

 

[terryplumb]

Yes, two and actually one of them is brand new. I don't know if they are on the relevant circuit though, they don't activate until it's dark.

If they don't activate when it's dark ,and your lighting circuit breaker is still off ,then they are likely on the same circuit.
Moisture in external lights and fittings is quite a common cause of RCD trips.

 

[zaarin_2003]

If they don't activate when it's dark ,and your lighting circuit breaker is still off ,then they are likely on the same circuit.
Moisture in external lights and fittings is quite a common cause of RCD trips.

I just checked (it’s dark now) and the new lights are working, so a different circuit.

 

[terryplumb]

Rules them out of the equation then .

 

[Harry Bloomfield]

But what we have had, is really, really cold weather (-7 at night). Our car doors have been frozen shut, the outside tap is frozen inside, that sort of thing. I mean, it's warming up during this afternoon, but could the cold weather have caused this?

Or could it more likely be something else?

The 'something else'.

I would check where you last suffered the water ingress. Just because it's not dripping, doesn't mean no water has got in.