Electrical Wiring

[AnonymousImport]

Hi friends,

I am DIY installing a triple plate spotlight to my ceiling, using existing wiring.

The previous homeowner had covered over with a blank plate, so I am not sure how to connect. The wiring is old/non-standard.

The live is double red (tested with mains tester pen). There is a double black and a single red. Anyone able to advise which is the neutral and which is the earth???

Thanks very much

 

[loftus75]

Leave the two red wires connected together, one of the black wires is a live switched wire, but as the polarities don't matter in the circumstances you describe, connect both blacks to the light, using one of them as if it were a red wire. To see which wire is the live switched wire use your tester to see which black one becomes live when the light switch is turned on and off.

Hope this helps.

 

[AnonymousImport]

Hi loftus75,

Thanks -- perhaps I should have mentioned that the 2x red wires are connected to one end of one of those small plastic two-screw connection blocks. The same is true of the 2x black wires and 1x red wire.

So I assume that they each need to be connected to one or other of the light fitting's 3xbrown live; 3xblue neutral and 1,yellow/green earth wires.

I thought therefore that the 2x red connects with the 3x brown in one connection block, live-to-live.

How would you make the connections...

 

[loftus75]

Okay, check the single red wire with your detector.

Turn the light switch on and off and see if this effects the power to that wire. If it goes live and dead in conjunction with the light switch, than that is your live switched feed. This will be used for the live side for your connection.

If the light switch doesn't effect the single red wire, then check the other wires the same way. You need to determine which is the live switched feed.

Once you've done this and have established which wire/s are the live switched feed, you connect the lighting unit as follows

brown going to the (red) (live switch feed,)

and the blues to the blacks

and the earth yellow/green to the earth point/wire.

Hope this is clear and helps.

 

[AnonymousImport]

Hi again Loftus75,

Well, it worked I think - thanks very much for your help.

The 1xred was the live switched - connected to browns. The 2x black connected to blues. The 2x red left unconnected to the light fitting.

There is no earth wire/point. I understand that it is not uncommon in old buildings (1930s mansion block). I double checked with other (modern) light fittings in the flat and they had no earth point/wire either so, as with those, I taped the light fitting's earth down to ensure that the earth wire touched the metal plate of the light fitting...

No buzzing, fuse-tripping, sparks(!) etc so I think job done....thanks again

 

[loftus75]

Glad to be of help. If your new light fitting is plastic or made of a non conductive material don't worry about th earth, but if it5's any type of material that will conduct you should try and get an earth to it.