Wiring 3 core light to ring main and extractor fan

[chrisgodridge]

Hi

I'm trying to fit a bathroom ceiling light that requires standard 3 core commection (earthy, live & neutral). My flat is old and runs on a ring main.

The old light had 2 sets of 3 core cables running in to it from the ring main, both with earth, live & neutral (coloured yellow /green, red and black). There was also a cable that ran in to the light connected to the extractor fan (not on a timer, just on/off when the light is turned on/off).

I figured I need to run all the above through a 30 amp juction box, with a single 3 core coming out that will connect to the new light.

In the junction box I connected the lives together (2 red from the ring main, 1 red from the extractor and the brown from the new light), all the earths together (4 lots) and all the neutrals together (2 black from the ring main + a blue from each of the extractor fan and the new light).

My problem is this, where does the yellow go (the remaining wire form the extractor fan)? When I take the cover off the extractor, the yellow is not wired to anything!!

I thurned on the curcuit without the yellow connected to anything AND without the new light connected and it threw a curcuit breaker. Was this due to the yellow not being connected, me wiring the junction box incorrectly or because I hadn't fitted the new light to the end of the relevant 3 core cable?

Would be greatful for any help!

 

[Taylortwocities]

I'll try and be polite

First off, it sounds thet you are connecting this fan to the bathroom light and the lighting circuit? This is not a ring main. If you've got one, the ring will be the way that the sockets are wired up.
Lighting circuits are not rings.

Second. All of this is described in the reference sections at the top of the Electrics UK forum.

Try here: //www.diynot.com/forums/viewtopic.php?p=65107#65107
How to wire a bathroom fan is number 9, i think.

Last off, please go to the WIKI and look at the section regarding electrical work and the law //www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law

Electrical work like this, in a bathroom, has rlegal implications..

 

[chrisgodridge]

Thanks for the reply... stern but educational... quite apparently I need to use a junction box with the addition of a switch terminal rather than a 3 way. Will get on that before the law catches up with me.

 

[333rocky333]

Do not join all the blacks together this time

Your so called [2 black from the ring main], one is neutral and one is the switch line.

By connecting the fan or light, to the [2 reds from the ring main] the fan or light supply will be permanently on, is that what you want.
rather than via the switch.

The unused yellow was possibly for a timer fan, which reguires a permanent live and a switch live, as well as neutral and earth.
If not used seal off in a terminal block both ends.