A couple of days to go before Christmas, when today the main RCD tripped all the electric circuits. Isn't it strange how these things always seem to manifest themselves at the time of year when it's virtually impossible to get a tradesman as they're all on holiday. Anyway, I was going around the house unplugging things one at a time, to try and locate the offending appliance. Eventually had everything unplugged and the RCD was still tripping out. Obviously not a direct short as it was taking 20 to 30 seconds for it to trip. So I was racking my brains, to try and find the solution to stave off a cold dark Christmas. I suddenly had a brainwave - the outside security lights! There are 2 x 500w lights c/w sensors at the rear of the house, plus it's a cold wet day, so a chance that moisture could be causing a slight current drain. More than likely it could also be one of the quartz strip bulbs which have a habit of fusing when they fail causing a short. So with the security lights isolated, I reset the RCD, and waited anxiously. Eureka! everything is still working. So my sense of impending doom has been replaced by one of illation. Merry Christmas, everyone.
Glad you found the culprit! Are outside lights meant to be on a fused spur so that would trip before all power went out? Kevin
The security lights are on a fused spur, but the fault is not a direct short. The RCD is tripping after about 20 to 30 seconds. so it must only be a small current leakage. The fuse has therefore not blown. The lights have been isolated and I'll find out what the problem is in the New Year - probably a blown Halogen bulb. I must replace them with LED flood lights when I get chance - far more reliable.
Even if you used an additional rcd combined with over current protective spur it’s a bit of a lottery which rcd would trip first. It sounds like the circuit has appropriate protection as described. Swapping to decent quality LED lamps is sensible but as you probably already know, avoid cheap eBay fittings.
Reminds me of that song - Burning down the house - A lucky escape on all accounts moreso, very fortunate you found the source... Last month we changed our Halogen lights to led, noting the wiring was brittle I changed that at the same time. The old wires were domestic black cable, not best suited for temperature changes or uv light, though initially run by an electrician (some ten years ago) I ran in outdoor SY protected cable, may be worth checking.... there’s also some good inline IP66 rated junction boxes which neaten up the install as I found a lot of the Led lights are sealed units with a short stub flex.
Yes, that would be earth leakage normally due to moisture as you know. My M in L has overhead cables (TT system) and she has a 100mA and a 30mA RCD as there is no earth. Years ago when I rewired the house I sank an earth rod in the front garden for her, went down 4.8m and still could not get a decent earth, so kept the 100mA RCD for safety. You can imagine how often hers trips! Usually Christmas Day when the boiler also gives up!
We got up last Sunday to a rather wet utility room floor. Turned out that something had gnawed through the dishwasher cold water feed pipe, and also the power lead so that the live conductor was visible. Easily fixed, but worrying, could set the whole place on fire.
Our downstairs trip switch went in the middle of the, night about 2 weeks back. Fridge and freezers fuller than usual, so we were not impressed. Since that night, one of the outside security lights has been out. I replaced it a couple of days ago and everything now fine. I'm sure it wasn't a coincidence.