CU change only one lighting circuit ???

[ianphilip007]

hi there

need a little advice when you change a C.U that currently has only one lighting circuit covering the whole property( upstairs and down) this circuit would need to be split into 2 seperate circuits before beeing connected to the new CU is my thinking correct re reg 314??

 

[Sparky Ste]

That shows that some customers do want lighting separated. Personally I would rather have the lighting separate but thats me personally. Also for those that said about BS7671 not being law, they are right but it can be used in a court of law against you should you not follow guidance set in BS7671.

 

[stuartcourt]

does my head in when I go upstairs then cant turn off hall light, lived here 7 years and thats my next job...............................
(and seen hundreds of switches for up and down)

 

[varilite]

Did you use rcd as main switch or did you use a split load kit keeping the lights off the rcd?

 

[Guitarist]

Just make sure that you don't have 2 different circuits going into 1 backbox, unless you are happy to label it as "2 points of isolation"

 

[GLENNSPARK]

So all of downstairs is in darkness. The lights upstairs are fine. Doesn’t help when bumbling in the downstairs cubby hole for the MCB.
If you want to take this to the extreme then every room should have it’s own MCB. BUT a room may have a centre light and wall lights, so that’s two MCB’s. One step further and each room should have it’s own radial for the sockets. We will finish up with every house having to have Sizewell B switching station under the stairs.

For goodness sake apply a bit of common sense, a two up two down only needs one lighting circuit. One or (two ring mains (kitchen separate), if you want to be extravagant). Cooker and shower.

When you’re rewiring the Ritz then think about splitting the lighting.

well on 2 up 2 down properties...such as back to backs then radials would be the circuit of choice....
why start utilising ring finals to feed 4 maybe 5 points....

 

[Gazthesparky]

I agree that it is better to have 2 lighting circuits and split them over the 2 RCDs with the downstairs lights on the RCD with the upstairs sockets And the upstairs lights with the downstairs sockets

i use to work for a big firm with lots of sparks and when the 17th came in and the duel RCDs became required I had a lot of call outs due to the sparks replacing the fuse box during the day and not testing the circuit properly. When it came to night time and the customer puts the lights on and the landing light on the RCDs would trip. This was due to a borrowed neutral in the landing.

 

[DPG]

They didn't even test that the lighting circuits worked ok? Classy. I take it they didn't do any ir tests or anything either then? Daz

 

[Gazthesparky]

They didn't even test that the lighting circuits worked ok? Classy. I take it they didn't do any ir tests or anything either then? Daz

No they obviously didn't test the circuits correctly. In some houses the landing light was fed from the downstairs lighting circuit from the switch at the bottom of the stairs and the neutral for the landing light was picked up from the upstairs circuit. Then when the landing light was switched on it would cause an in balance and cause the RCDs to trip due to the borrowed neutral

 

[Guitarist]

It is becoming more apparent with each passing month that many so-called electricians don't have a clue how to test anyway, so the above posts don't surprise me in the least.