Tripping MCB - Upstairs Lighting

[tatters40]

Hi

Hope you guys can help

Upstairs lighting circuit is tripping the MCB, it trips between 1min and 15minutes!

My daughter was ill the other night and we ran a very hot bath bath with some nasal remedy's in the early hours (docs recommendation) for her to inhale, obviously all doors and windows were shut for maximum effect, sometime during the early hours the MCB must have tripped as no upstairs lighting was available in the morning, i have removed switches, roses and the shaver point etc to check for moisture and loose connections but none was noted, it may have just been coincidence!!

Can anyone help please?

Tatters40

 

[PrenticeBoyofDerry]

Have you had any work carried out in the house recently?
Does the MCB trip, then if reset trip straight away, then trip almost immediately?
And if left after it trips and reset does it take some time to trip?

 

[tatters40]

Have you had any work carried out in the house recently?
Does the MCB trip, then if reset trip straight away, then trip almost immediately?
And if left after it trips and reset does it take some time to trip?

Thanks for the reply, generally if i reset it it trips again after around 2 minutes, it has taken as long as 10 minutes and in this time i have switched the upstairs lights on and off so it does not trip when the lights are switched on

 

[PrenticeBoyofDerry]

So has there been any worked carried out of recent?
And it is the MCB not an RCD or RCBO?
It sounds like and insulation resistance fault, this could be a nicked cable in the back boxes or a snagged cable, this is best checked out by an electrician.
If it trips quite soon after tripping and resetting, the thermal overload is still warm and that is why it trips soon afterwards.
If it is left awhile after tripping and then takes a little longer to trip this is because the thermal overload has cooled down a little.

 

[tatters40]

So has there been any worked carried out of recent?
And it is the MCB not an RCD or RCBO?
It sounds like and insulation resistance fault, this could be a nicked cable in the back boxes or a snagged cable, this is best checked out by an electrician.
If it trips quite soon after tripping and resetting, the thermal overload is still warm and that is why it trips soon afterwards.
If it is left awhile after tripping and then takes a little longer to trip this is because the thermal overload has cooled down a little.

Hi Mate, thanks again

No recent work, just happened out of the blue, its an MCB and the switch is under a little note saying`not RCD protected`i have removed all the upstairs light switches and nothing obvious etc but i`m not a sparky

Tatters40

 

[PrenticeBoyofDerry]

You could try a process of elimination.
Firstly with power on and all the lights off.
Then at each switching point for the lights.
Trying one light on at a time.
See how the system reacts and if you can nail it down to one part of the circuit.

 

[tatters40]

You could try a process of elimination.
Firstly with power on and all the lights off.
Then at each switching point for the lights.
Trying one light on at a time.
See how the system reacts and if you can nail it down to one part of the circuit.

Will give it a go, think it will probably trip before i manage to get upstairs to try this but thanks

 

[PrenticeBoyofDerry]

If it does trip with all the lights off. Just try disconnecting the shaver socket from the circuit. This must be disconnected with the power off and see what happens.

 

[JohnD]

look for nails in walls, floors or ceilings near a cable run

look for signs of rodents, including in the loft

look for a heavy or metal object put down on a cable in the loft.

look for a source of water, especially a leaky roof or pipe in loft or over a ceiling rose or JB, or an outside lamp if fed from the lighting circuit

 

[tatters40]

If it does trip with all the lights off. Just try disconnecting the shaver socket from the circuit. This must be disconnected with the power off and see what happens.

Hi mate, just had a rumage, the trip has been off all day, switched the main switch off and had a look in light fittings and upstairs light switches etc and also up in the loft, whoever was here before seems to have just laid board but not fixed it etc but we have quite a bit of stuff up there but it has not been disturbed for some time.

Anyway reset the trip then flicked the main switch the upstairs lighting main tripped very aggresively this time with a small flash and no delay

Think i may have disturbed something etc

Any thoughts

 

[PrenticeBoyofDerry]

tatters40,
Your best option is to call an electrician and get some fault finding done.
The problems not going to go away and needs resolving, right sharpish.

 

[ljarrald]

most likely answer... mice.

 

[Spark123]

What sort of light do you have in the bathroom? Fully enclosed globe, downlight etc??

 

[tatters40]

What sort of light do you have in the bathroom? Fully enclosed globe, downlight etc??

Hi, normal bulb and shade original fitment, never been an issue previously

Paul