Lightning strike

[reubens]

Last Tuesday we had an almighty thunderstorm (overhead lightning strikes), which tripped the power in the house. As it was just our house and not a general outage, I reset the trip on the consumer unit. It kept tripping every minute or so, decreasing in time until it wouldn't reset. I switched off all the breakers and turned them back on one by one (unplugged everything in the house beforehand). This narrowed it down to the upstairs sockets which tripped every time it was switched on. There was nothing plugged in at the time and the emersion is on a different ringmain. (excuse me if I have the wrong terms but I'm no electrician). Before I call an electrician out and waste money, Could it just be the circuit breaker that needs replacing? I haven't taken it out and checked as yet because it's dark when get home and don't want to be without any power. It remains in the off position so I have power to the rest of the house. Could a power surge have burnt out a right main and if so, a rough guesstimate of costs before I call insurance company?

 

[JohnD]

From your description I gather it is an RCD that has tripped, not an MCB.

It is quite possible from your description that the upstairs socket circuit, or something plugged into it, was damaged by the lightening. It is also possible that the RCD has been damaged and is tripping from a slight earth leak that would not normally be a problem. Lightening can do strange things

Unplug all appliances to see if you can identify a faulty one. there may also be applances (like wall heaters or outside lamps) that are connected with a fixed fused switch, not a plug - turn them off too.

If it isn't an appliance, then I think you would do well to call your insurance company, explain as you have done, and ask if they have an approved local electrician on their panel who can find and fix the fault.

there is also a possibility that the storm may have let rainwater in somewhere, do you see any signs?

 

[reubens]

There is still nothing plugged in and the RCD remains off (if that is the row of circuit breaker switches on the panel on the consumer unit, excuse my ignorance). If I switch this on, then the main trip switch trips. There is no sign of water damage anywhere and the only water heater is working fine. I do have outside lights which are still working so obviously not from that ringmain. It wouldn't just mean the circuit breaker is buggered then?

 

[sm1thson]

(mcb =the individual circuit breakers for each circuit that replace old fused, RCD=device with reset button that detects earth fault and (in this case) act also as the main switch)

basically (it appears to me) there is a fault on your upstairs ring so when you turn it on (via the mcb) the RCD trips (RCD's are more sensitive to faults where electricity is going to earth trips at 30mA rather than the 30A of your mcb).

either there is a new fault or, as john said, the circuit was leaking slightly before (this is normal especialy for cookers immersion hearters etc) and the RCD has now become more sensitive (this does happen) so is tripping when you turn it on.

as john says water would be the first thing i would look for, are you sure you dont have anything connected, a TV booster in the loft would be a prime suspect! after that its electrician time that will quickly test an RCD then do an insulation test on the ring wiring to test that, then split the ring to find what part has the problem and what will need doing to dig it out and change it!

 

[reubens]

Thank you for that. There is no booster in the loft and there is absolutely nothing plugged in (only have 6 sockets upstairs).

I guess it will be an electrician after all.

 

[Pensdown]

IMO you should contact your insurance company at once and explain what has happened. They will cover the cost of the test and any repairs that may be required.

As Johnd said, lightning can do some very strange things and it does sound like your installation has been damaged.

 

[RF Lighting]

One more thing just to check,

Is it possible that you have an external light fed from that circuit.

From what you have said it sounds unlikely, but worth checking.

 

[Gaz the Sparky]

lightning can do strange things as stated above i've been out to faults where lightning has hit the tv ariel come down to the tv blown the tv up blown the socket off of the wall and left a big black mark on the wall then when i came to test the rcd it had welded itself on it would not trip at all even when i tested it at five times the rating!!!!!

so it could have done a number of things best to get an electrician in to asses the damage id call your insurance company and see what they say

 

[HiZ]

I'd hardly say a blown up telly,black marks and welded contacts are 'strange' things.

Sound quite normal.... im sure your would chnage colour an stop working if you had a millon Amps put through you!!!

Strange is when the smoke detectors start bleating because the air get ionised and send them a bit crazy!

If I were you do all the insurance stuff etc but just so you know whats going on I'd whip the socket tops off upstairs and you may well find one of the sockets is damaged or a conductor has melted to the back box etc. 10mins works and a replacment socket from Homebase might solve the problem.

I doubt a fault would occur in the cable under the floor, its more likely to be where it nears or crosses an earthed item. Having said that, nothng to say it couldn't have jumped and welded to a water pipe....

If anything looks badly damaged then get a spark, even if it is just to test the earth loop impedance once the repair is completed.

 

[sm1thson]

strange is when ball lightning comes down your chimney, round the room 3 times then out of the window. -but thats not helping your problem, but i think all has been said that can be untill a pro does some tests.

 

[reubens]

Thank you for all your comments. Yes I was lucky that there is no great hole in the new roof or anything has blown up (and no ball of light in the house). I will check the sockets first and warn the insurance company of impending claim.

Thanks Guys and I will keep you posted

 

[reubens]

Great news, it was a conductor on an upstairs socket. All it cost was a new socket and everything is working Thank you to everyone, saved me a few quid

 

[HiZ]

Great news