DIY wiring likely to cause RCD trip

[Gareth Davies]

The people who lived here before me wired outside security/night lights not to the lighting circuit but to a socket ring. Although controlled by a wall switch the lights actually plug in to a socket inside.

It's not the best job in the world.

I've been using the lights with my old style fuse box and a plug in RCD which does trip every now and again - probably three times a week.

I'm having the fuse box replaced with a consumer unit and I am pre-empting nuisance tripping from these lights.

Is is best to just disconnect them completely or is there any way of isolating them so that they don't cause nuisance tripping?

[meow2222]

If you run a cable from them back to the CU on its own RCBO, it wont affect anything else. You'd also need to fix the cause - probably bugs, dirt or rain in the luminaires.

NT

[Brian Gaff]

Erm, what. Surely if they are plug in then you can just unplug them. Personally outside lightin run off the mains can be a real pest. Most of the lights I've seen lately that are not floodlights are low voltage ones. Brian

[Adrian]

Which will required the full installation to be checked out and certified, so the problem will almost certainly be resolved within that.

Dual-pole RCD where they come into the house, and switch that off when you don't want anything on that outdoor circuit?

[philipuk]

The answer here is to fix the cause and not the effect. If the lights are problematic you might as well just have them replaced along with any cabling.

As you are having the consumer unit replaced, a dedicated RCBO and circuit to run the lights is the rolls royce solution and means any tripping won't affect another circuit.

Philip

[fred]

In article , Gareth Davies writes

The only way to do this without the risk of nuisance tripping is to use a dedicated circuit on an RCBO in the consumer unit.

Outdoor circuits are the most at risk from physical damage and moisture ingress so you don't really want to risk them causing problems with internal circuits.

You will need to properly check the complete outdoor run and junction boxes but bear in mind that plug in RCDs are really intended for task related (reset, plug in, cut grass remove) use rather than long term installations so although rather to frequent, those trips may be spurious. Plug in RCDs are often cheap junk and can trip on mains transients (or sometimes, it seems, changes in wind direction) so while you may have a problem with that circuit, you may not.

I found this after exporting power to a greenhouse over SWA (armoured) cable and made a temporary hook up with an RCD plug. After a few unexplained trips I was suspecting my installation skills but when I swapped the lash up for a mini-CU with a proper RCD, the tripping problems disappeared.

[Gareth Davies]

Thanks - yes two of them have plugs but there's a third run that is directly wired in to the socket. I figure it's worth just disconnecting the whole lot without having phantom cables coming out of walls.

[ARW]

I would just unlug the outside lights and say that they out of the remit of the test (subject of the agreed contract of the electrical test).

Or to put it into Yorkshire speak "Your outside lights on that plug are shagged. I have made a note of this on the cert and it's up to you what you would like to do about this".

No need for double pole RCD switching unless it is a TT supply (and even then it's not all that important).

Double pole switching for outside lights is always a good idea if it is a shared RCD.