O/T lighting ring circuit

[Roger Ford]

Just went to replace a standard hanging light fitting with an Ikea ceiling light, and find myself very confused.

 

There are six wires coming in - 2 blue, 2 brown, 2 earth.

 

Currently, the light is powered from the two blue wires, and the two brown ones are just connected to each other, and not to the bulb at all.

 

Is this normal?

 

And since the Ikea light doesn't seem to have provision for connecting other wires, should I just use a chocolate block to connect the browns in the new fitting?

[duffield]

The lighting circuit is called a loop circuit, You need to advise some more information,

 

1 Was the original light part of some other lights that are in that room or is it on its own?

 

2 is the switch that operates it one of 2 switches.

 

3 Have you got a meter and have you knocked of the MCB?

 

For info, Brown is live, Blue is negative, Green and yellow is earth. Be very carefull not to electricute yourself.

 

 

Edited by - duffield on 22 Oct 2011 14:30:10

[Richard Price]

Currently, the light is powered from the two blue wires, and the two brown ones are just connected to each other, and not to the bulb at all.

 

Is this normal?

 

Yes. It's normal!

One of the browns is the supply, which is then looped out to the switch.

The switch will have a brown going into it, and a blue "switch wire" coming out of it to feed the light fitting.

 

should I just use a chocolate block to connect the browns in the new fitting?

 

Yes.

 

 

[Roger Ford]

1 Was the original light part of some other lights that are in that room or is it on its own?

 

It's the only one.

 

2 is the switch that operates it one of 2 switches.

 

Single switch.

 

3 Have you got a meter and have you knocked of the MCB?

 

Yes, I've got a meter (about six at the last count ) and the circuit breaker for the lighting circuit is off.

 

For info, Brown is live, Blue is negative, Green and yellow is earth. Be very carefull not to electricute yourself.

 

Yeah, it's not the first time I've wired anything I was just confused about this one! Brown = colour of earth, so obviously live. Blue, colour of electricity so obviously neutral. Or something.

 

[blade_runner]

one of the blue wires should have had some brown sleeving on it as its the switch line, and is live!

this is due to using 1 length of twin & earth to drop to the light switch.

the brown of this twin and earth will be connected to the brown, thats the live supply comming from the consumer unit,

the blue wire in the length of twin and earth, coming back from the switch will be live when the switch is closed, and should be marked in brown with sleeving, or brown insulation tape.

so at the terminals of the light fitting you end up with a blue (neutral) that comes from the consumer unit, and a Blue (which should be sleeved brown and is live ) comming back from the switch. all perfectly normal.

[Roger Ford]

No brown sleeving. But never mind, all done now with a minimum of sparks or electrocution.

[Johnty Lyons]

I don't know what Dick wired it in the first place but using TW&E for a switch wire instead of twin Brown is very amateurish and i'll bet it wasn't done by any competent Electrician.

Have wiring standards slipped that much recently.