Home Electrical Problem

[josadler7]

Hi
Please can you help? one of the bulbs upstairs in my house blew recently knocking out the trig (Hager Breaker) I then set to finding the failed bulb and changing it, there are 4 in the circuit and then reset the trip.
Unfortunately one of the room lights now won’t work (Bulb is new and tested ok) so I changed the switch, but this did not help.
The breaker has a test switch which trips when pressed which indicated that either the breaker or the circuit has an issue, changing the breaker is expensive so can anyone guide me on next steps?
Thanks
Jo

[Old_Geezer]

If only one of 4 lamps in a circuit will not light, and you know the bulb is fine, that implies to me a probable breakage in the lamp fitting. It may be worth turning off the juice and inspecting it.

[josadler7]

Thanks Old_Geezer, I tried that and I couldn't find anything obvious wrong but I didn't have a multi meter at the time so could be worth trying again, would a failed bulb knock out the lamp fitting?

[Old_Geezer]

Vice versa would be more probable. Given the lack of meter, at the risk of incurring multiple wrath from all those who disapprove of them, a neon screwdriver can help gain confidence as to whether the live is getting there when the switch is flipped. Be careful though. A lit neon says positive, an unlit one only implies there might not be, but ... And be sure you don't short anything. A face full of molten screwdriver is not good news.

[The Builder]

Re: the test button............ it's normal for the device to operate when this is pressed. That means it's working.

Multi-lamp fittings can be a right pain. Possibly a loose connection has become even looser.

What are the bulbs..........

Halogen with a 2-pin GU10 fitting?
Ordinary bulbs?
Bayonet or screw fitting?

[josadler7]

Thanks The Builder
Bulbs are Bayonet, energy saving
I checked the light fitting circuit with a meter last night and I couldn’t find a problem – no short.
Another bulb blew this morning knocking out the trip again, so it’s not just the one bulb circuit as I thought.
Seems there is a fault somewhere in the lighting circuit (5 room ceiling lights)
Thanks
J

[The Builder]

Jo .......If it's an RCD that keeps tripping, then that would suggest a fault to earth. That may not show up on a test for a simple live to neutral short circuit. I can't say without knowing exactly what you tested.

If it's the circuit breaker that goes (quite different from the RCD), then that would suggest short-circuit or overload.
It's hard to correlate the fault with the incidence of bulbs blowing though.

Perhaps, a loose connection somewhere is arcing. This could cause flickering that might blow a fluorescent type low energy bulb to fail. It is possible that this could result in the circuit breaker operating.

You can go around in circles with possible theories.

The way I would approach this, and I guess most electricians as well, would be to take the light fittings down, expose all the wiring, and test each part of the circuit separately. A process of elimination Jo.