Bathroom light wiring problem

Melter · 17 Sep 2004

I'm making some changes to my bathroom and one of these includes installing a proper light fitting as the bathroom currently has the standard bulb on the end of a flex (which I thought was a no-no in bathrooms). Of course the existing wiring will not all fit in the new light.

Looking at the current wiring it appears to be similar to the diagram below and I thought if I put all these into a junction box I could then run a cable to the new light fitting.

Wrong. There are actually four cables wired into this ceiling rose. Starting from the left:
Block 1 goes: Blue (first hole) - Red/Black (second hole, with the black having red tape around it).

Block 2 goes: Red/Red (first hole, with one red having red tape around it) - Red (second hole) - Red (third hole).

Block 3 goes: Black/Black (first hole) - Black (second hole) - Brown (third hole).

I'm a total novice to this but does that sound right to anyone? I've had a quick look in the loft and I think one flex is going to the bathroom light switch, one is going to the bathroom fan, one to the front bedroom, and I think one to the back bedroom (not confirmed though).

Any suggestions for the way to go to install my new light? Thanks.

Beamish · 17 Sep 2004

You don't say, but I'm assuming your new light fitting has one block with space for three wires ?

If so...

Remove the existing light fitting.

Connect all the wires from existing block 2 (All the red ones) together in a separate block. (these do not connect to your new light)

You need to get all the earth leads together and connect them to your new light fitting.

Connect the wires from the existing block 1 into the appropriate position on your new light fitting

Connect the wires from the existing block 3 into the appropriate position on your new light fitting.

That's all.

Melter · 17 Sep 2004

Okay sorry to be a numpty about this but just need a bit more clarification. The new light comes with two blocks: one has a place to fix in the fitting and the other is provided for loop in/out connections and supply earth termination. The spare block doesn't seem to fix in place anywhere like the first block so if needed is it safe to leave loose in the fitting.

The instructions are:
Block 1
Supply Neutral Blue or Black - Light Fitting Blue
Supply Switched Live - Light Fitting Brown

Block 2
Supply Loop - Light Fitting Loop
Supply Supply Earth

There's also a warning that the fitting is double insulated and must not be earthed.

sparkydom · 17 Sep 2004

Hi Melter,

You basically need to replace the blue and brown wires that go to the pendant flex with a length of 1.00mm/1.5mm T+E, aslo now connecting earth (as the pendant did not have one) to your new light fitting

All the wires that go to "block one" in your exisitng light need to be connected together at one terminal in your new junction box, and all those in "block two" need to be connected together, and the same for "block three"

Hope this has helped

Dom

Melter · 17 Sep 2004

Not really as that now gives me a solution for using a junction box and one for just using the new light. If I can just use the new light then that would be preferable so if someone can second Beamish's solution clarifying what wire's go where then that would be great.

breezer · 17 Sep 2004

trust me use a junction box, its easier, it will give you more room in your new light. (instead of trying to cram in 4 cables)

sparkydom · 17 Sep 2004

Hi,

I agree with Breezer, much easier. plus less likely to damage a cable when it comes to forcing them all into the new fitting

Thats the way in which I have installed mybthroom light, and many of the other "non pendant" fittings in my house.

It also makes it slightly easier to fault find, as apposed to just having three or four cable coming through the cieling and not knowing where they come from

Melter · 17 Sep 2004

Ok thanks that seems the more sensible option. As I'm a novice at this and for my own reference can someone explain why the current wiring is set up the way it is. Why is it safe to have a red and black wire in the same point, I thought you weren't supposed to mix wires?

breezer · 17 Sep 2004

i could expalin it, but its easier if you look in the sticky for refenece section, it has a variety of drawings etc

ban-all-sheds · 17 Sep 2004

Melter said:
Why is it safe to have a red and black wire in the same point, I thought you weren't supposed to mix wires?

It's OK - the electrons can't see the colour of the insulation.

Melter · 17 Sep 2004

Okay I get it stop asking stupid questions.

ban-all-sheds · 17 Sep 2004

Not that - just my attempt at humour...

Damocles · 17 Sep 2004

Funny, thought i just posted her. wonder where it went? nice post about wire colours?

It said, the black with red tape is an honourary red. Probably the red with red tape goes off to the switch, and power comes back on its paired black..with the red tape..which is sometimes live, sometimes not. Sometimes people use special cable with two reds in it.

Then I remarked on it being a bad idea to mix up this black with the other blacks, since switching on would then result in a big bang.

But I remember it being a more humorous post than this one. wonder where it went?

Melter · 19 Sep 2004

Realised I've got three earth wires to fit in somewhere. Where do I put these?

breezer · 19 Sep 2004

4th terminal

diynot

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Bathroom light wiring problem

breezer

breezer

breezer

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