Today I’d like to offer advice on how to replace a light switch. It’s a very common thing to do, and there are a lot of people that get confused when they do it and get mixed up, and it is quite easy to get mixed up if you don’t know what you’re doing.
So there are a few basic precautions that you’ve got to follow when you’re doing it so I’m going to tell you how to do it now.
The first thing you need to do is to switch off the lights that you’re working on and any other lights on the same circuit, and then you need to go to the fuse box and isolate the circuit that you’re working on. So I’ve switched off this circuit, now for the lights… before you start working you’ve actually got to confirm that it is dead, there is a chance of when I went to pull the fuse that they light should stop working anyway, maybe one of the bulbs went, so I can come here, tear the cover off, and get a nasty shock or even get electrocuted, so you have to confirm that it’s actually dead before you touch any of the wires, I’ll tell you how to do that as well.
Remove The Old Face Plate
So first of all we’re going to remove the first plate. Now that we’ve removed the screws we can pull the first plate forwards exposing the wires, but before we touch any of the wires we have to confirm that the wires are dead, this may look like any old screwdriver to you, what it is it’s actually a test screwdriver; if you hold it by the tip and put it on any of the wires that are live it will actually light up to in the care that the wires are live.
So I’m actually testing it now and it’s not illuminated so it does look like everything’s dead. When you’ve done that you’ve got to confirm that you’re screwdriver’s still working by testing that on a normal working appliance. So just to prove that my screwdriver’s still working I’m going to test that on something that I know is live… and I know that this flex is live because I’ve got my burlap hooked into it. So when I put it on there you can see that it illuminates which is proving to me that that is live. Now I’m going to go over here and test these cables, it’s not live so these are definitely dead so we do know that we’ve isolated the correct circuit.
Mark The Wires
Before removing any of the wires you need to mark them up, so many people swap a first place over like that and then they’ll have 6 maybe 8 wires there and they won’t have a clue where they go back, and then they’ll probably come to our forum and come and ask us where they go and we don’t know because we weren’t actually there when they took it off and it’s almost impossible to work out by someone saying “Oh well I’ve got 5 red wires and 3 black wires,” that tells us nothing. So it’s really important at this stage to actually label up each wire and where it goes to. Although this is a very basic setup we’re still going to use masking tape to mark where everything goes just so that you know when you come to do it where everything goes.
Now I’m just going to get a piece of masking tape and label up each wire. I’m not actually going to label up the line wire between the 2 columns because it’s obvious what it is, I actually know what it is, so now we’ve marked everything up we can now remove the old line switch… tear that out for now.
If you look at your light switch your should be able to see the terminals clearly, you’ve got your comm terminals there at the top and then L-1 and L-2 terminals at the bottom. Now you’d only use the L-2’s on a 2-way lighting circuit, not a one-way. So this is the new light switch we’re going to be fitting… and if you look at this one it’s actually a little bit different because the comm is not at the top on both of them like it was on the one we’ve just taken off, so you’ve got comm there and comm there, so when we put this back on we need to put the linking wire between those.
If you look at your light switch now you can see that the back box is earthed, it’s got an earthing wire going to it, when you fitting a metal access it will always having an earthing terminal on it, it’s like a little earth symbol, and that means that it must be earthed. So the best way to earth a light like this is to take a wire from the earthing terminal on the back box to the earthing terminal on the accessory, so it’s really easy to do, all you need is a piece of copper wire.
Install An Earth
So the first thing we’re going to do now is install another earth wire, so we’re just going to do this terminal up here so we can get the earth wire in, that’s nice and tight. Now we’re probably going to need about that much wire so we’ll just snip that off and then when we fasten the copper conduct to the back box like that you can just put a piece of green and yellow earth sleeving on it, to ensure that it’s the earth wire. So now we can reconnect all the wires onto the new light switch. So now we’ve got our earth wire on, and we’ve got all our other wires marked up, we can now put the new light switch back on. So I’ve removed the masking tape from this one now because I know where this wire’s going, it’s going into the comm terminal.
Check Your Work
It’s important to make sure that at this stage that you’ve got your light switch the correct way up, so we’re just going to put that wire into comm, along with this wire. And then as I said earlier that’s the link wire so that needs to go into the other comm terminal. I’ll just remove the masking from that one cause I know where that one’s going. And then it’s just this last wire and I know where that one’s going to I can remove the label from that one now. Once you’ve connected all your wires like that it’s a good idea to test them all to see if you can pull them all back out, and if you can’t you obviously need to redo the connection. Now the last thing we’re going to connect up is the earth wire, which is what we put in earlier.
This particular light has a plastic plate like that that sits behind the light switch but you can put this on at any point, some people find it easiest to put it on right before the wiring. When you push your light switch back to the wall it’s important to make sure you don’t trap any wires. So now we’re just going to pop the screws back in. And then before you tighten it up just make sure that it is straight. When you tighten the first plate back up you can then restore the electricity.
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