Electrical Light Issue

[GreigM]

Can any sparks (professional or enthusiastic amateur) help me with a lighting wiring fault.

I have a set of outside lights which are controlled by an electronic timer switch inside. The wiring for this is very simple - just a single pair of live/load wires - as basic as a switch gets. This has worked without issue for years.

A few days ago the circuit breaker for these lights tripped on the consumer unit, and the fuse in the electronic timer switch had blown. So stuck in a new fuse and reset the breaker, and the lights were stuck permanently on - none of the timer controls (or its switch) had any impact and the only way to kill the lights is to remove the fuse again.

So I thought it must be a fault with the electronic timer switch, so replaced it, but exactly the same effect with a new unit (different brand/model).

In the meantime I've wired in a good old fashioned manual switch, but would like the electronic one to work.

So whats the likely cause - I'm thinking it'll possibly be a short in one of the light fittings outside, and the only way to tell is to change/remove them one by one....is this the correct way to go about it?

[driverrob]

By circuit breaker do you mean ELCB, RCD or old fashioned over-current breaker?

[GreigM]

Sorry, I call it a breaker - just the switch on the consumer unit for that circuit (RCD?)

[netherfield]

I'd say the timer is cooked.

[Dogwatch]

Has a short developed which is jamming the electronics of the timer(s)? If fuses are blowing and circuit-breakers tripping then leccy must be going where it shouldn't.

[dave_s13]

Some of thes timers work thusly:-

- Switch supply off/on quickly = Light stays on permanently
- Switch supply off/on with 3-5 sec between off then back on again = timer function restores.

Imagine you are working outside on something for a long time, this gives you the option to have the light on all the time rather than going on/off every 30secs.

So.....Try turning off the supply to the timer/light - wait 5 sec - turn back on.....see if that sorts it.


Did you RTFM??

[GreigM]

I did RTFM, but it was more of a note than manual, and it was FU.

However....I have got it working....checked the outside lights, one had a crack in the glass and was sitting in a puddle inside it - so removed it from the loop and the new timer switch is working perfectly....old one is still gubbed, but that not a problem.....