Please help!

[skamuk]

I went to an emergency job today. All downstairs lights not working. Apparently a bulb blew and tripped the MCB. Replace bulb, flicked MCB back up no lights at all!

In fact, if you switch on a light the bulb (energy saving) would flicker like an indicator on a car.

So, first thing I did was change MCB for another that I know was working and this told the same story..

So I then located the first lighting point in the circuit and wired it up on its own, flicked the MCB and it came on, so I added the next light into the circuit, also came on.. did this for all 13 lights downstairs and everything worked!!! Although I was left with two wires in two different locations that lead nowhere (as far was we could gather, as the cables ran under the floorboards which the customer didn't want taken up unless absolutely necessary). I could only assume that these were the cause of the problem and were maybe redundant. All lights work in the house now and as far as I was concerned the problem was solved!

Put all light fittings back and tested everything, fine. Packed my tools got my money and left.

Just received a phone call from the customer saying they have all gone again! apparently they just went on there own, then after making a phone call they came back on again! and then off again 5 mins later!

I'm currently studying 2365 at college and have a good understanding of how a lighting circuit works, but I am lost now!!!!


Is it the MCB?


I've got to go back there late tomorrow morning, some advice would be great!

 

[trev]

Bizarre fault but I'd start with checking terminations

 

[rmc86uk]

Of you changed the circuit breaker for new then surely it's not that at fault.

Are they low voltage down lights? Had a problem before where all down lights were fed from one transformer and the they would come on, off, on, off. Changed transformer and it worked fine.

 

[markc123]

You sure someone isn't flicking the switch on and off behind your back lol?

It's been done before.

 

[Des 56]

Check the neutral connections back at the supply end,my bet will be on a problem in that area

 

[skamuk]

Of you changed the circuit breaker for new then surely it's not that at fault.

No, I meant to say I tested with another B6 that was currently in use for upstairs circuit that was working, no result so I put the suspect one back as at the time, it was not the problem. All lights worked on this MCB after re-terminating everything.

Cant see my terminations being the problem, especially to cause the whole circuit to stop working..

 

[Mork]

Try the connection of the mcb on the busbar.

 

[skamuk]

Will check neutral at board tomorrow, seems like the only other possibility other than the MCB, at least to me!

There are 9 low voltage down lights in the kitchen area. All working before I left, none working when I got there, not even flickering like the ceiling roses in the other rooms.

 

[markc123]

Funny one this.

Erm, 13dodgy lampholders lol?

 

[skamuk]

:dizzy2:

 

[markc123]

Are they on dimmers or just normal switches?

 

[skamuk]

Are they on dimmers or just normal switches?

Just normal one way switches. One two gang two way switch for landing upstairs/downstairs.

 

[skamuk]

Bear in mind EVERY SINGLE LIGHT in the house worked before I left! And the MCB has not tripped but all downstairs lights are now off!

 

[Plonker 3]

Check all connections, change all the lamps, also carry out a IR test on the circuit. See if you can trace all cables as there could be a badly connected JB or the like somewhere on the circuit.

 

[Sintra]

Saw something similar were L & N were looped through the switches. The neutral choc block on the first switch was loose causing intermittent failure on lighting circuit.