Lights randomly do and dont work

Hi

About half our upstairs lighting suddenly stopped working a couple of weeks ago. The bizarre thing is that the lights will suddenly come on, usually in the middle of the night. I think where the switch has been left in the on position the connection mysteriously starts working again at random times. But they dont work 99% of the time.

What can be causing this?

A broken/poor connection halfway along the circuit on the permanent live loop wire. Might be in a junction box or might be a fault in a damaged cable.

You need to get it checked as an intermittent connection could overheat or arc and cause a fire.

Anyone been moving things about in the loft and dislodged or trodden on a cable?

A loose connection about half-way along the upstairs lighting circuit.

You need to find it before it starts a fire. When it suddenly stopped working, had anybody been in the loft?



Doh!

You don't say what type of lamps. If using transformers often these are switch mode power supplies with an auto shut down system to switch them off with bulb failure. Wrong size bulbs can cause these units to seem to have a mind of their own.

Again the GU5.3 pins run very hot and these also often reconnect as they cool they should not in theroy do this but often they do. Only cure is new holders.

Switches do fail I have just changed one and only 30 years old being two way and only one set of contacts failed it would depend on the other switch of the pair on if it worked or not.

Wires do not generally fail but years ago we used screw terminals for wires before maintenance free because popular and vibration can cause these to become loose.

As already said bad connections can mean heat so it needs curing. I would go for simple first. With power off go around with a terminal screwdriver and test all connections for tightness and genital pull to see if any wires are not in the holes. Do remember on a radial circuit it could be the lamp before the effected lamp which is causing the problem.

Next I would renew the switch as they are cheap and easy to swap.

As to transformers don't even know if your using them or not. So come back with more information.

Ericmark said...


tightness and genital pull

thanks for the replies.

yes i have been up in the loft recently...

what can i do as an immediate measure to make the problem safe? should i switch off all upstairs lighting from the fuse box?

tan8856 said:

thanks for the replies.

yes i have been up in the loft recently...

what can i do as an immediate measure to make the problem safe? should i switch off all upstairs lighting from the fuse box?

Click to expand...

If that won't significantly increase the risk of you falling down the stairs, probably.

And get a long extension lead and a good inspection lamp so you can see what's going on in the loft, where you probably snagged a cable.