On Nov 12, 6:05*pm, "David WE Roberts" wrote:
"David WE Roberts" wrote in ... Just set off to do my good deed of the day.
Replacing the PIR outside light by the front door which had given up the
ghost.
New light half price from Homebase was the incentive :-)

snip
My conclusion is that somehow in moving the wires around I have induced a
short between live, neutral and earth somewhere in the power wire which
disappears into the cavity wall to gawd knows where.
Have I missed anything which might be good news?

snip

I was double checking that the central heating was off the lighting circuit
by taking the CB up half way (this gives power - full up trips) whilst
someone watched the programmer for signs of life.

I had just used this trick to locate any lights still turned on and turn
them off.
To my surprise, after I heard the boiler fire up the breaker stayed set.

So I am now wondering if the CH was just putting too much load on the CB
when first reset - the initial suge knocking it over again.

So the thing I do need to confirm - in a power cable from a lighting circuit
where some lights may be turned on should I see an open circuit between live
and neutral?
Doesn't seem right to me.
Seems more likely that a small contact has burned itself out during the
repeated short power ups.

I am now not going to touch anything until it is daylight and the house is
toasty warm.

Then presumably I play hunt the phantom fault.

The whole account of full of question marks. I'd disconnect the CU end
of teh cable, and use a multimeter to check what the circuit is doing,
plus establish what all the wires are at the light end. Ultimately if
it cant be fixed, run new cable, but hopefully you can find &
disconnect the faulty part of the circuit. We cant, its jsut a case of
test, divide & conquer.


NT