Wiring

[Frinks]

Hi folks!

Some advice if you can be of help please?

I wish to replace 2 light ceiling fittings with 2 that use a totally different loop type connection/rose.

The new fittings have the standard wiring connections as instructed. The connections are Blue, Brown and Green & Yellow. Standard plug type.

The current fittings use a loop type connection with three sets of wires to each. I guess these sets are looped as follows...

1 set for each of the 2 fittings in the main room and 1 set for the kitchen. These three fittings make up the group in the main fuse box.

Wire colours to each fitting within the current connection/rose...

3 red
3 black
2 green and yellow

Now, the loop type connections....

These have 6 brass terminals as follows and are currently set as follows...

2 Loop - All red connected here
2 Neutral - 2 black wired here AND Blue wire from light fitting itself
2 Live - One black wire and the brown wire from the light again

I have found that the previous owners of the house have not made sure the wires were tightend fully in one of the fittings. It was loose. This broke the loop and none of the lights in the group worked.

I have purchased replacement light fittings for the main room and want to know why there is a black wire connected to 1 of the live terminals on each of the roses?

I want to remove each of these roses and use the current wiring (three sets of red,black and yellow/green/earth and connect them to the new fittings.

Have been advised that the red sets would go to Live on new fitting, black to Neutral and Yellow/Green to Earth.

Am I making sense?

Sorry to be a pain! Have replaced these before but the wiring was simple and straight forward. Ohh yes! Did I mention the two current fittings/connections in main room are of dimmer swith type.

Many thanks!

UK.

 

[breezer]

see sticky for reference

 

[Damocles]

You need to keep the connections exactly as they are. current brown and blue are where the new lamp brown and blue should fit in.

The trick is that one cable pair of black and red goes off to the switch. Dimmer makes no difference.

 

[Pentewan]

A picture would help!

It looks as if the wiring is conventional. You will have one three-core cable (red, black, green/yellow) coming from the distribution unit bringing power to the fitting. A second three-core cable (red, black, green/yellow) will go from this fitting to the next one. A third three-core cable (red, black, green/yellow) will be "looped" down to the switch (or dimmer, in your case).

At the ceiling fitting all three red wires are connected together at one terminal. This allows live power to reach the switch/dimmer via the switch loop cable, as well as to reach the next fitting. At the switch, the black wire will be connected to the other terminal. This is where the confusion comes in. The cable going to the switch really ought to have two red cores (and a bare earth core that is sleeved green/yellow at the ends). But that's more expensive than standard red and black cored cable, so most electricians use standard cable. But in this case they should have put a red PVC sleeve over the exposed black sleeve at the switch end to show that when the switch is closed this black wire is live. Back at the ceiling the same black core of the loop down to the switch (which is now a "switched live") should also be sleeved red, and at that point connected to the live side of the light fitting (probably via a brown core in a flexible cable).

Finally the black wire from the power feed cable coming in and and the black wire from the power feed cable going out to the next fitting are connected together and to the neutral side of the light fitting (probably via a blue core in a flexible cable).

Hope this helps.

 

[Frinks]

Many many thanks folks!

This place is great! Have a good week.