circuit breaker on lights tripping when nothing's on...

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ssme

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hello, i'm not an electrician but hoping for some advice from one (or several)...

at 3am this morning the circuit breaker for the downstairs lighting in my house tripped. i reset it, and it tripped again 15 minutes later. i changed the only bulb that was on thinking that might be the problem, and there were no more trips.

later, when i was in bed and all lights were off, the breaker tripped again. it keeps tripping at fairly regular intervals if reset even with no lights on, so at the moment it's just left off, which is fine in daylight...

any suggestions on what would be best to do next? how much would it cost to get an electrician out to check what needs to be checked?

thanks in advance!

 
Sounds as if you have a fault on the permanently live part of the circuit which is all live up to each light switch even when no lights are on.

Not sure of call out charge in your area but best to ring around a few local contractors and get an idea.

You could try the FIND AN ELECTRICIAN page on this site and see who is near by.

Just looked for you and PC Electrics covers WARKS.

 
thanks for the replies.

no lights outside, all that's on the circuit is 6 light fittings and an extractor fan (downstairs bathroom) that hasn't worked for years. i had a suspicion last night that as it was a wet and very windy night maybe some moisture might have got in through the extractor vent but if that's the case it's taking a long time to dry!

how much work would it take for an electrician to isolate the fault if its a fault on the live wire? would it be a matter of removing light switches and testing there, or would all the upstairs floorboards have to come up to check all the wiring?

 
The circuit can normally be tested without lifting floorboards depending what wiring system you have, if it is a fairly modern loop in system then connections are all accessible at light fittings and switches.

 
hmmm... there is a possibility of rodent damage as there have been some scrabblings in the cavity. if there was some damaged wiring somewhere, would it be possible to isolate and locate the fault without taking floorboards up, or would all the wiring have to be visually inspected to locate it?

needless to say, even getting to the floorboards upstairs to lift them is likely to be a massive undertaking ; \

 
It may be possible to isolate it but you may not have some lights working afterwards!.

IF it is damaged wiring then it will need replaceing, we have many tricks up our sleeve as to how that can be done with minimal upheavel.

YOU can trust a reputable electrician to do only what is required at a reasonable cost.

NO ONE can solve your problem on here alone!

Make a call and trust a professional.

 
thanks for the reply. when i said 'isolate' i meant pretty much the same thing as 'locate' i.e. would it be possible to locate the rough area where the fault is so that only a minimal number of floorboards need to be removed and only that section of wiring replaced?

i will have to make a call in the morning, but i want to be forearmed with as much knowledge as possible. i take your point about a reputable electrician, but i'm not sure i know of any!

 
ssme,

I'm sure you'll have a member near, one of the earlier posts suggests PCElectrics from here he's a good 'un one of us and apparently he covers your area, however, you would need to contact him to see how far away etc. you are and to sort things out.

I would link to his details or the find an electrician bit but I'm not that good with the forum software!

 
Yes depending as said on how your lights are wired it is normal to locate the section of wiring that is faulty by means of testing with minimal disruption.

A competent electrician would only need to lift floor boards if required when he/she has determined the immediate area likely to to be the fault location.

Sometimes a fault may be proved to exist between 2 lights and that section rewired. sometimes it can just be a fault within a light fitting or light switch.

Let us know how it goes, It may be better to call in a registered local Contractor (NICEIC, ELECSA etc) not just any Local spark.

Registered Contractors have had to prove their ability in testing!

 
Have a look at the top of this page, " Find an electrician" . As said above PC is in Coventry according to the map. Also as said , look for membership of NICEIC, ELECSA, NAPIT, ECA, or BS .

 
thanks for the reply. when i said 'isolate' i meant pretty much the same thing as 'locate' i.e. would it be possible to locate the rough area where the fault is so that only a minimal number of floorboards need to be removed and only that section of wiring replaced?i will have to make a call in the morning, but i want to be forearmed with as much knowledge as possible. i take your point about a reputable electrician, but i'm not sure i know of any!
depending on hidden connections and access, a decept sparky can usually identify which cable is faulty, and guess its most likely route. also, depending on site conditions, it may be easier to forget about faulty cable all together, and take a different route from A to B

have a look in the find a sparky thread and there may be someone on here close to you

 
if you were concerned about rodent damage take a look in your loft

and look for obvious damage...and droppings !!!!!

 
unfortunately the possible rodent activity is in the downstairs ceiling/upstairs floor cavity, so it's not so easy to check. thanks for the link, it's returned a long list that i can look through in the morning!

are the accreditations actually worth anything? i remember reading about how people could simply buy CORGI registrations and things, so do these electrical equivalents have any real weight?

 
unfortunately the possible rodent activity is in the downstairs ceiling/upstairs floor cavity, so it's not so easy to check. thanks for the link, it's returned a long list that i can look through in the morning!are the accreditations actually worth anything? i remember reading about how people could simply buy CORGI registrations and things, so do these electrical equivalents have any real weight?
In short yes they do, the experiance or workmanship of the individual can be some times questionable, but the back up and complaints procedures ensure that you will always be protected, unlike those who are not registered.

 
Have we established if this is an

MCB

RCBO

or

RCD

tripping???

Hello ssme... welcome to the forum...

This simple facts are

1/ it could be something easy and straight forward to find and fix in one visit..

2/ It could be a real sod needing more than one visit to track down....

Intermittent faults are by their very nature "intermittent" so its possible you could come along and do some tests which are all OK cuz the fault symptoms are not present.

IF you had rung me up with these symptoms I would be suggesting an initial investigatory visit of up to two hours, opening up accessories and testing whatever cables are found.. for around the

 
Thanks for the mention guys. I'm actually in Lutterworth, but it's just a short ride through the country lanes into Nuneaton.

As Specs says, it's like the proverbial "how long is a piece of string?". It could be an intermittant live to earth short, perhaps due to nicked insulation. It could be rodent damage. It could be a faulty MCB (have come across this before).

On a very basic level, simply disconnecting the circuit at the board and carrying out an insulation resistance test should show whether there is a fault present on the circuit. Of course, being an intermittant fault this cannot be assured.

Assuming the IR test shows a fault then the next stage is to start splitting the circuit down trying to locate the fault. It's at this point that the time factor becomes a big unknown.

Once the faulty length of cable is identified, a 'fix' needs to be developed and implemented. Until we know 'what and where', we can't know what is required.

Some questions:

Has any work been carried out recently?

Had any water leaks?

Put any pictures up?

Do any of the lights 'flicker'?

Changed any of the lights or switches?

 
Thanks for the mention guys. I'm actually in Lutterworth, but it's just a short ride through the country lanes into Nuneaton.As Specs says, it's like the proverbial "how long is a piece of string?". It could be an intermittant live to earth short, perhaps due to nicked insulation. It could be rodent damage. It could be a faulty MCB (have come across this before).

On a very basic level, simply disconnecting the circuit at the board and carrying out an insulation resistance test should show whether there is a fault present on the circuit. Of course, being an intermittant fault this cannot be assured.

Assuming the IR test shows a fault then the next stage is to start splitting the circuit down trying to locate the fault. It's at this point that the time factor becomes a big unknown.

Once the faulty length of cable is identified, a 'fix' needs to be developed and implemented. Until we know 'what and where', we can't know what is required.

Some questions:

Has any work been carried out recently?

no, no work carried out recently.

Had any water leaks?

no water leaks that i know of.

Put any pictures up?

no.

Do any of the lights 'flicker'?

they don't flicker, unless you count the energy saving bulbs taking a few seconds to get up to full strength.

Changed any of the lights or switches?

no, none of the lights or switches have been changed.
thanks for the response, please find my answers to your questions above. i'm a little concerned about the intermittent issue. i don't want to be spending hundreds of pounds calling electricians out only to be told there isn't a problem every time. if there is a problem with the wiring is there no way it can be diagnosed as problematic even when it is not manifesting?

having said that, i just tried resetting the switch, and it lasted about 30 seconds on this occasion so it's not as intermittent as it was...

 
thanks for the response, please find my answers to your questions above. i'm a little concerned about the intermittent issue. i don't want to be spending hundreds of pounds calling electricians out only to be told there isn't a problem every time. if there is a problem with the wiring is there no way it can be diagnosed as problematic even when it is not manifesting?having said that, i just tried resetting the switch, and it lasted about 30 seconds on this occasion so it's not as intermittent as it was...
Hello ssme, you have either got to spend some money to start breaking the problem down, or leave it and carry on as you are. As the guys have said, a cable defect will most likely be evident on the insulation resistance test. But without doing the basic tests you will not be able to start correctly evaluating the cause. Your options are buy or hire appropriate test gear and do it yourself, or employ someone to come and do it for you. I don't think you will be able to get much more diagnosis without someone actually seeing the faulty circuit, there is only so far you can go with on-line help.

Doc H.

 
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