My consumer unit contains an RCD trip switch. It recomends that this switch be tested quarterly. According to the instructions on the unit, all power should be 'lost' when it is pressed. However, my dowstairs lights remain on. Why is it doing this? I had downlights installed a few months ago, will this be the problem?
RCD's on Consumer Unit
- Thread starter kennymc
- Start date
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Quite likely the RCD protects your socket circuits and your electric shower (if you have one) but not the lighting circuits.
This is quite normal, it is safer to cut power on sockets (as you might be using an electric tool outside in the rain, or dropped your kettle in the sink, so at risk of shock); but safer not to cut power on lights (as you might be up a ladder; carrying something heavy, or running downstairs, so at risk if it goes unexpectedly dark).
If you describe the layout of your consumer unit, we will be able to tell you if that is how it has been done. If not, then the new lights may have been wired in an unusual way.
For example, starting at one side, I would expect to see something marked "Main Switch - 100A" that is about twice the width of the other things, then a few narrower MCBs marked "Lighting up - B6" or similar, then maybe an RCD (large again) marked "30mA" then some smaller MCBs marked "B32 - Upstairs Sockets" or something like that. You may also see that some of the MCBs are marked with a sticker in Red, and some in Green.
This is quite normal, it is safer to cut power on sockets (as you might be using an electric tool outside in the rain, or dropped your kettle in the sink, so at risk of shock); but safer not to cut power on lights (as you might be up a ladder; carrying something heavy, or running downstairs, so at risk if it goes unexpectedly dark).
If you describe the layout of your consumer unit, we will be able to tell you if that is how it has been done. If not, then the new lights may have been wired in an unusual way.
For example, starting at one side, I would expect to see something marked "Main Switch - 100A" that is about twice the width of the other things, then a few narrower MCBs marked "Lighting up - B6" or similar, then maybe an RCD (large again) marked "30mA" then some smaller MCBs marked "B32 - Upstairs Sockets" or something like that. You may also see that some of the MCBs are marked with a sticker in Red, and some in Green.
Then the layout is probably (take the blank plates in the middle as the dividing line) that the MCBs on one side are RCD protected, and the MCBs on the other side are not. This is quite usual, it is called a "Split Load" installation. If you can lay your hands on a digital camera and put up a photo we can probably explain more.
The circuits you describe next to the main switch are the ones that would not usually be put on the RCD.
Do you see a red sticker or line on one side, and a green one on the other? Should be just under or over the labels with circuit names on. May be on the labels themselves.
The circuits you describe next to the main switch are the ones that would not usually be put on the RCD.
Do you see a red sticker or line on one side, and a green one on the other? Should be just under or over the labels with circuit names on. May be on the labels themselves.
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Just tried the test switch again. It seems you are right. Everything to the left of the blank plates stays on, and the sockets etc to the right go off. I cant believe I didnt get onto this straight away! I was more worried about a poor installation of the downlights by so called professionals!! Thanks for the quick relpies, youve put my mind at ease cheers.
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