Tripping 6amp breaker

[cagedanimal2010]

just to be pedantic when you I.R tested did you operate all switches?

 

[eco-tech]

Sorry stupid me regarding the outside light lol

I put them all in the on position to get my reading.

Just can't understand why it trips after a hour and not when its switched on

 

[cagedanimal2010]

any 2 way switches?

 

[eco-tech]

Yes But I connected them out the circuit etc.

As it happens one of the 2 way switches does not work as it should

Do you think this is the problem ?

It only works if one of the switches is in the on position.

 

[eco-tech]

Me now thinks loose live in this circuit !

 

[Richard Burns]

Have you tried a clamp meter on the lighting circuit to see what it is pulling (even if all the lights are off) if it is tripping after an hour and is not faulty then it should be taking about 8A.

Then you need to find where there is a cross connection. If there is no RCD protection then between L and N.

 

[Octopus]

I had a problem like this once to look at - and set a date thefollowing week to come back.

In the interviening time, the "after a while" became more shorter and by the time I visited switching on a specific light meant the circuit would trip immediately.

The fault was caused the gentle knawing through of the switch cable by a mouse!

 

[fuzzydunlop]

Had something like this last week, tracked it down to a poorly terminated common cable on a two switch dimmer.

 

[ringer]

Have you tried a clamp meter on the lighting circuit to see what it is pulling (even if all the lights are off) if it is tripping after an hour and is not faulty then it should be taking about 8A.

Then you need to find where there is a cross connection. If there is no RCD protection then between L and N.

8A Richard?????
Do you think he is using 240W lamps?

To the OP definitely check all terminations, particularly if you think there is too much copper showing - that is indicative of poor workmanship by whoever installed it.

 

[Deleted member 9648]

Try changing the MCB if tests are ok and no overloading issues....they can fail.

 

[eco-tech]

Looks like I will be pulling floors up on this one grrrrrrrrrrrrrrrrr


Sounds like a loose connection grrrrrrrrrrrrrrrrrrr


Thanks chaps I will keep you posted.

 

[micknew]

If there is a delay before it trips a possible cause is carbon tracking somewhere, this would show up testing with a megger at 500V.

 

[eco-tech]

Carbon tracking ?

 

[eco-tech]

oh arcing

 

[micknew]

A carbon track is formed when an arc usually caused by dampness between 2 bare conductors.
The track of carbon becomes more conductive with heat until the current being passed takes out the circuit breaker.
This could account for the delay you have experienced.
Not uncommon behind outside light fittings that have not been sealed around connections.
Google it.