splitting a 2 gang light switch to two seperate switches.

[ollieman]

I have a single room which I am splitting into two rooms this weekend. There are 4 recessed downlights on one side of the existing room and 3 on the other side. These lights are operated from a 2 gang light swicth. One switch operates one side of the room and the other switch operates the other side of the room.

My question is what alterations do I need to make to have two individual light switches, one in each room? The existing two gang light switch has four cables coming out of it. One for the left hand lights, one for the right hand lights and I assume two power cables from a junction box in the loft void above.

Thanks for any help.

Ollieman.

 

[riveralt]

For the lighting arrangement you have described you would normally expect two sets of T&E cables (2 brown/red 2 blue/black & 2 CPC) is this what you mean by 4 cables or are there four T&E cables?

If there are four T&E cables then it is likely that your have the line/neutral and earth coming into the switches. Is there a terminal block in there which connects all the blues/blacks together?

 

[Chri5]

Sounds like loop in out done at the switch, rather than at the ceiling rose or a jb in the loft.

Would you please take a picture to qualify what's going on in the existing switch.

 

[ollieman]

I can recall before the second fix was done that the cables (which are all (T+E) were labeled as follows:
F+N
F+N
Right Row
Left Row

The electrician told me that if I want to split the room then I would need to take a cable from the existing light switch to the new light switch. I was hoping that the lights would be on a junction box system as this would have been far easier to make adjustments too. I'll take a photo tonight.

Cheers.

Ollieman

 

[riveralt]

I can recall before the second fix was done that the cables (which are all (T+E) were labeled as follows:
F+N
F+N
Right Row
Left Row

If your lights are being looped through the switch, then your current set up should be : your four neutral conductors should be connected together in a terminal block and your cpcs to the backbox. Gang one should have one feed (brown or red) to the C terminal and the second (right row? brown or red) to L1. Gang two should follow similar lines.

The electrician told me that if I want to split the room then I would need to take a cable from the existing light switch to the new light switch. I was hoping that the lights would be on a junction box system as this would have been far easier to make adjustments too. I'll take a photo tonight.

You will need to take one of the Feeds out and one of the 'rows' out of the double gang and wire the remaining single gang as above. Then run the removed cables to the new switch and wire as above.

 

[Chri5]

Or run a TE from the existing switch to the new one.

Lopp in out at the switch is good ( makes testing easy due to being at switch not at a ceiling rose), but is a minor PITA regarding movement.

If the whole house is loop in out then ideally the new switch position would be.

To do that you'd need to:-

Pull back one of the LNE feeds from old to new switch, provide a loop link between the 2 switches and then re route the feed to the lamp set from old to new switch position.

 

[ollieman]

Thanks for the help guys, I've had a look behind the switch and the 4 blues are all connected in a connector block, all the earths are also connected in a seperate connector block. Seems it is a loop in at the switch if thats the correct terminology. I'll do as you both suggested. Thanks,

Ollieman.