Why Is Your New Light Fitting Tripping?

[Music] hello i'm roger bisbee from the skill builder channel and i just want to cover a little thing about wiring that i used to get this question all the time when i was doing my lbc fix-it phoning program on a saturday morning it came around time and time again and the problem is that what people do is they decide they get fed up with their light fitting maybe they've got a chandelier and chandeliers are not in fashion anymore so they go down to argos or wherever they buy a new light fitting take the old one down and then they wire up the new one and i think they've done a good job you know they put the reds for the reds the blacks with the blacks and you know we all know that uh you know this is old-fashioned colors now because they'd be brown they'd be blue but whatever it is we know that the brown is live and the blue is neutral or in this case the red is live and the black is neutral so it's very easy for us to wire that up and then of course the whole thing goes bang they just keep blowing the fuse and then they're at their wits end and they're either calling in an electrician or they're phoning me up so let me just explain to you what's happening here what we have in the uk and i'm only talking about the uk here so don't all you americans and australians and people get vexed by this but what we have is what we call a looping system where every light fitting is joined by a a cable that comes out of a fuse box and it doesn't go back to the fuser box so it's not a ring main it's just a loop in system so if we look at this coming in now we've got a and this is the cable coming in say from the fuse box or wherever it is and it says one or 1.5 millimeters because that's the sizes that they have and i use the 1.5 millimeters for all this and i just use the one mil for going down to the switch but that's by the buy let's just say what we've got so coming in on a we've got a live and we've got a neutral which is fairly easy there's the earth as well coming in now that goes on to our next fitting that live so we would want that to continue going out to wherever we've got another fitting so we would have another wire going out of there and it would go on to our next fitting and similarly with the neutral we'd have another wire going out to our next fitting or this could be the one on the end of a line in which case you wouldn't have another wire coming out it would look like this so when that wire comes in that live needs to go down to the switch so there's a live conductor going down to our switch and our switch is just a very simple on off switch here nothing fancy no two ways so when that switch goes across it makes the circuit and at this point we've got a live going back up on the black wire now the reason it's black is because the cable comes either with a brown and a blue or a black and a red as it used to be and that's the kind of cable we're using but we've now said that this is a live wire it's not a neutral wire so hence he's put a red flag on it there a bit of tape around it and now you would get a brown sleeve and you would put the brown sleeve over the blue so that you've nominated this as live so when it comes back into the light fitting it's not a neutral and this is where people go wrong because they take that black wire and they connect it up to there and of course what you're doing is you're connecting alive to a neutral and that's why it goes bang so so long as you remember when that wire is coming back from the switch it is actually alive and it's got to go into the live and that joins the live that now runs down to the light fitting the light the lamp holder whatever it is you've got a pendant light or a chandelier or whatever you've got same principle it's going down to the light fitting and it's switching the light on so our neutral is coming straight from the neutral because that's not switched and that goes down to the lamp holder there our earth is coming out of our earth terminal and that's going down to our lamp holder there so the only one we're really worried about is when this live comes in we need to have that live going down to the switch across the switch back up and back into the what we call the batten holder the rose or whatever you want to call it the junction box in the ceiling that has these terminals in it and that is the one that is now going down to the light now the reason we do this the reason we have this system like this rather than putting a switch on the actual you could just put a switch straight on there if you like but the reason we don't do that is because we like to rationalize all the connections and make sure that all the connections are actually in accessible places so if there's any problem in the future the electrician can come along he can disconnect the wires he can put his little tester on there and just test every single wire so he knows where the problem is you know if it's a switch here test the switch individually so having those accessible all our connections made either at the switches or at the light fittings themselves is a way of making sure that we don't have any hidden junction boxes under the ceiling which could be causing a problem in the future and then he's got to go hunting those out lifting floorboards breaking up floor tiles all sorts of things to find the problem so i hope that explains what i've been talking about just go through that here's the supply coming from the fuse box it goes into the ceiling rows there and it goes from the ceiling rows down to the switch through the switch back up and at that point it is a different color cable but we nominate it so we change it we sleeve it so that it's the same color as the other one so we know that's red that's red they go together and that will run down to the light fitting so i hope that's helped it's a very common problem as i say and one that's mystified many people for a long time and roger bisbee come back and see us soon we're going to do a bit more we're going to do some central heating wiring next so if you're into that come back and watch us

Channel: Skill Builder

Views: 40,883

Keywords: wiring a light switch, wiring a light fixture, wiring a light switch and outlet, wiring a light switch to a light fixture, wiring a light switch and outlet on same circuit, wiring a light bar to a toggle switch, wiring a light socket, wiring a light switch off an outlet

Id: -Nz1sMGx3TU

Length: 6min 9sec (369 seconds)

Published: Wed Feb 02 2022