Blown light Circuit

[jULI4NT]

Hi all,

While turning on the bathroom light, the bulb blew, tripping out all of the upstairs lights. I turned the trip switch back to the on position with no problems. However, my lighting has still not been restored. Could this mean that the MCB itself needs replacing? if not, how could I test the circuit for the fault.

 

[Taylortwocities]

Is it just the bathroom lights that dont work, or is it still all of the upstairs lights?

 

[ericmark]

Try switching off and back on again. The trips are designed not to allow you to defeat them if there is a fault so with some switching on while the fault still exists will result in leaver in on position when switched off. You can normally feel it is wrong by lightness of leaver.

When a bulb blows often you get ionisation inside the bulb which caused the bulb to go black and internal fuseable wire inside bulb to go before the main fuse. But MCB's are sometimes more sensitive than a fuse and go before fuseable wire inside the bulb. Try removing bulbs or switching off lamps where you know direction of switch in case another bulb has blown going short circuit as it blows. Then switch on one by one until fault is found.

Some times MCB's do fail but not very often.

 

[jULI4NT]

Hi again,

It is all the lights upstairs. I have tried switching off all lights and retesting the switches, but all appear normal on the fusebox.

When turning off the MCB and turning back on there is no noticeable difference to the others. There is no resitance when turned back on, but the lights still do not work.

The only thing that came to mind was a faulty MCB, or perhaps damaged wiring?!?

 

[ban-all-sheds]

A faulty MCB is unlikely.

I take it that nowhere in the house had any work just been done which might have impinged on the electrics? Even non-electrical work like drilling or nailing into walls/floors/ceilings?

 

[bongos]

Hi again,

It is all the lights upstairs. I have tried switching off all lights and retesting the switches, but all appear normal on the fusebox.

When turning off the MCB and turning back on there is no noticeable difference to the others. There is no resitance when turned back on, but the lights still do not work.

The only thing that came to mind was a faulty MCB, or perhaps damaged wiring?!?

Is the bathroom light the first light in the circuit upstairs? If you have got (or can get) a multimeter then test to see if you have got 230V at the bathroom light or anywhere else on that circuit. Don't use a neon screwdriver to test though.

 

[ColJack]

turn the power off, then carefully remove the light switch from the wall / ceiling and see if there's any loose or broken wires, or if there is any signs of scorching / flash marks anywhere..

 

[jULI4NT]

it appears that the mcb is okay as one light is working upstairs but no others. what would be the nect thing to check?

Thanks for all your help

 

[ban-all-sheds]

You can't really go on like this - as I see it there are only two sensible courses of action.

1) Learn how lighting circuits work, learn the route(s) that yours takes, and then combine those to trace what works/doesn't work. At the point where working becomes not working you'll find the problem.

2) Get an electrician.

 

[ColJack]

make your mind up.. you said none of the upstairs lights were working..

with thte power off...!!!!

take the working light down / unscrew the cover and see if there is a loose wire in there.. give the wires a tug..
if not then it's a case of best guess which way the cable runs to check the next light for the same..
push comes to shove, have a look in all of them..

if they all look fine and none of the cables will pull out then it might be that something has happened to the cable out of sight, in the loft maybe?
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