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

[Lurch]

I think this thread has run it's course. You need to either get someone to look at the fault you have or leave it as it is and hope your house doesn't burn down.

Have you even called an electrician yet for some pricing information? Have all your local electricians said it will be hundreds of pounds to look at the fault, even though none of them will know what the actual fault is as has been pointed out.

You need to call an electrician, discuss prices and go from there.

 

[Andy™]

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...

many intermittent faults can be found even when its not faulty at the time

 

[ssme]

[quote name='Andy

 

[sparkytim]

If any help I had similar call today.

"Ring main MCB Tripping every now and then over last few days, getting worse will only stay on 30 secs or so"

(Pre 16th Edition Installation NO RCD on this circuit)

Arrived at 2 PM walked thru property un-plugged all appliances and switched off all Fused connection units, Disconnected Alarm panel N from un-switched spur and removed fuse, re-set MCB and it tripped again soon after.

Disconnected circuit in Consumer Unit did Continuity test of Ring and L to N all Ok (This Confirmed nothing still plugged in or connected to circuit),

Did Insulation Tests L-N 20 M ohm, ok N-E 20 M ohm ok, L-E .001 M ohm.

Diagnosis Low Insulation fault L to Earth.

Went to approx mid point of Ring, double socket in bedroom furthest corner of Bungalow from Mains.

Split Ring and Disconnected SWA taken from this socket to Lamppost in Garden.

Returned to Consumer Unit retested and Fault gone.

Took Meter back to socket position in bedroom and tested SWA to Lamp post- confirmed fault on spur to lamp post. Went to Lamp post opened up to find Fused connection Unit feeding Time switch which was switched Off, no obvious fault IN lamp post confirmed fault in SWA cable.

Customer never uses Lamp post so happy to isolate it.

Chopped SWA cable off in back of socket, put every thing back to-gether, retested Ring continuity and Insulation resistence at C unit, all now + 200 M ohms. Powered up did Loop test at socket in Bedroom and a couple of others.

Had a cup of Tea and chat, suggested up grade to 17th Edition standard, wrote out my invoice, payment in pocket and out of the door at 3PM.

Basic call out charge for 1 Hours Labour, no materials used.

Problem solved and a happy Customer.

 

[ssme]

If any help I had similar call today."Ring main MCB Tripping every now and then over last few days, getting worse will only stay on 30 secs or so"

(Pre 16th Edition Installation NO RCD on this circuit)

Arrived at 2 PM walked thru property un-plugged all appliances and switched off all Fused connection units, Disconnected Alarm panel N from un-switched spur and removed fuse, re-set MCB and it tripped again soon after.

Disconnected circuit in Consumer Unit did Continuity test of Ring and L to N all Ok (This Confirmed nothing still plugged in or connected to circuit),

Did Insulation Tests L-N 20 M ohm, ok N-E 20 M ohm ok, L-E .001 M ohm.

Diagnosis Low Insulation fault L to Earth.

Went to approx mid point of Ring, double socket in bedroom furthest corner of Bungalow from Mains.

Split Ring and Disconnected SWA taken from this socket to Lamppost in Garden.

Returned to Consumer Unit retested and Fault gone.

Took Meter back to socket position in bedroom and tested SWA to Lamp post- confirmed fault on spur to lamp post. Went to Lamp post opened up to find Fused connection Unit feeding Time switch which was switched Off, no obvious fault IN lamp post confirmed fault in SWA cable.

Customer never uses Lamp post so happy to isolate it.

Chopped SWA cable off in back of socket, put every thing back to-gether, retested Ring continuity and Insulation resistence at C unit, all now + 200 M ohms. Powered up did Loop test at socket in Bedroom and a couple of others.

Had a cup of Tea and chat, suggested up grade to 17th Edition standard, wrote out my invoice, payment in pocket and out of the door at 3PM.

Basic call out charge for 1 Hours Labour, no materials used.

Problem solved and a happy Customer.

i'm not even going to pretend to understand all that but it sounds like you did a very thorough job!

 

[Andy™]

i'm not even going to pretend to understand all that but it sounds like you did a very thorough job!

what he said is basic fault finding that any electrician would know. even if you had a test kit, i very much doubt you would know what its telling you and what to do next.

 

[muffin]

rodents have a taste for cables so this is more than likly to be the cause.

i would get some form of rodent trap/killer asap to prevent more damage.

even if this turns out not to be the cause it will prevent other damage

however i expect you will find the little ball of fluff lead across the wires slowly being cooked everytime you reset the mcb for a bit longer.

if you are handy with diy then you could lift the odd board around where you heard the rodent. this may well show signs any damage and lower the cost of a sparky doing it.

its always worth starting with the obvious

hth

 

[ssme]

rodents have a taste for cables so this is more than likly to be the cause.i would get some form of rodent trap/killer asap to prevent more damage.

even if this turns out not to be the cause it will prevent other damage

however i expect you will find the little ball of fluff lead across the wires slowly being cooked everytime you reset the mcb for a bit longer.

if you are handy with diy then you could lift the odd board around where you heard the rodent. this may well show signs any damage and lower the cost of a sparky doing it.

its always worth starting with the obvious

hth

thanks. i think that's what we might try, as there aren't going to be people around to receive an electrician during working hours for a few days. as mentioned before, it will take a while to get to the boards so we're going to clear and check a few obvious points under the boards first of all. what sort of damage should we be looking for? cuts in the insulation?

one thing that would be helpful if someone could explain: the consumer unit we have has a 'test' button for "RCD controlled sockets" which is meant to switch off the whole supply, but when i pressed it only the downstairs sockets went off. a closer look at the unit shows that the 'd/s sockets' switch is the only one to have "RCD protected" written above it. is this what is meant to happen? or does it indicate a faulty unit?

and the circuit breaker for the lights is very definitely staying off at the moment. i've always preferred plug in uplighters going to the loo by torchlight is a novel experience too

 

[Lurch]

one thing that would be helpful if someone could explain: the consumer unit we have has a 'test' button for "RCD controlled sockets" which is meant to switch off the whole supply, but when i pressed it only the downstairs sockets went off. a closer look at the unit shows that the 'd/s sockets' switch is the only one to have "RCD protected" written above it. is this what is meant to happen? or does it indicate a faulty unit?

It would depend on the configuration of the unit.

 

[sparkytim]

Sounds as if you have a Split load Consumer Unit which provides two levels of protection, basic MCB protection for lighting circuits and up stairs sockets with Additional RCD protection for the downstairs sockets only.

This was an arrangement under the 16th Edition of the wiring Regs when RCD protection was only a requirement for socket outlets Likely to supply equipment outside, hence downstairs sockets covered but not up.

So nothing to worry about as RCD trip button will only disconnect the circuit connected thru it.

Things to look for are anything in the way of obvious damage, if the pesky rodents have been active then you will soon see chew marks, cable sheath missing (thats the outer covering) and even insulation missing showing shiny copper conductors.

They can get thru tiny holes in the back of switch boxes and normally chew near holes thru joists trying to squeeze past cable running thru.

 

[Andy™]

thanks. i think that's what we might try, as there aren't going to be people around to receive an electrician during working hours for a few days. as mentioned before, it will take a while to get to the boards so we're going to clear and check a few obvious points under the boards first of all. what sort of damage should we be looking for? cuts in the insulation?one thing that would be helpful if someone could explain: the consumer unit we have has a 'test' button for "RCD controlled sockets" which is meant to switch off the whole supply, but when i pressed it only the downstairs sockets went off. a closer look at the unit shows that the 'd/s sockets' switch is the only one to have "RCD protected" written above it. is this what is meant to happen? or does it indicate a faulty unit?

and the circuit breaker for the lights is very definitely staying off at the moment. i've always preferred plug in uplighters going to the loo by torchlight is a novel experience too

so your going to spend hours (/days) taking up various boards to check every cable, rather than get a sparky who will tell you exactly which cable is faulty, most likely within 30-45 minutes. he will also know its most likely route and where to look.

and the RCD will switch off whats connected. which from your description is only the sockets.

a little knowledge is dangerous

 

[ssme]

[quote name='Andy

 

[Bacon]

Have you baited any traps may just catch somethink and it will point to the likley cause.

 

[batty]

If you do have vermin I would get that sorted before they do anymore damage. In my area Glis Glis are a real problem and they chew through cables like theres no tomorrow. Squirrels are another culprit and if you have Rats I would not enter your property until they were got rid off.

 

[Badger]

If you do have vermin I would get that sorted before they do anymore damage. In my area Gliss Gliss are a real problem and they chew through cables like theres no tomorrow. Squirrels are another culprit and if you have Rats I would not enter your property until they were got rid off.

what on gods earth are gliss gliss's

 

[batty]

what on gods earth are gliss gliss's

They are little bu..ers only available in the chilterns.

http://www.amersham.org.uk/glis.htm

 

[Andy™]

what on gods earth are gliss gliss's

Fat/edible mice, according to google

 

[Badger]

ohh you learn something new every day, cheers andy.

 

[steptoe]

thanks. i think that's what we might try, as there aren't going to be people around to receive an electrician during working hours for a few days. as mentioned before, it will take a while to get to the boards so we're going to clear and check a few obvious points under the boards first of all. what sort of damage should we be looking for? cuts in the insulation?one thing that would be helpful if someone could explain: the consumer unit we have has a 'test' button for "RCD controlled sockets" which is meant to switch off the whole supply, but when i pressed it only the downstairs sockets went off. a closer look at the unit shows that the 'd/s sockets' switch is the only one to have "RCD protected" written above it. is this what is meant to happen? or does it indicate a faulty unit?

and the circuit breaker for the lights is very definitely staying off at the moment. i've always preferred plug in uplighters going to the loo by torchlight is a novel experience too

you arent likely to be able to get an electrician for a couple of weeks anyway,

unless you are lucky and hit an empty day.

dont expect a decent spark to be at your beck and call, as much as we are in a downturn, its mostly the cowboys and 5day wonders that will be able to come when you want, and they will just charge you a bomb and still mess about with no idea.

RING A REPUTABLE SPARK AND ARRANGE A MUTUALLY SUITABLE TIME AND PRICE FOR 1/2 DAYS FAULT FINDING.

(expect to wait a week or so at least I would expect)

that is your only answer.

 

[Doc Hudson]

if it IS rodent activity then it will almost definitely be within a ~3 ft wide area in one of two small rooms, so the number of boards to raise is restricted somewhat!

How can you be sure rodents will only chew things around where you think they may have been. Most rats, mice etc. will travel around various parts of a property on the hunt for food, nesting locations, warmth. You have no way of knowing what they may chew through whilst moving around. You say the fault is on the downstairs lights, so it is the downstairs ceiling & upstairs floor area, I would assume they have come from outside into your property which probably covers quite a large area of travel?

Doc H.