New wire colours for 2 way switch

[DavidM]

Rewiring the 2 way landing light switches. Have pulled cables in new colours:

a) Brown/blue/earth from landing ceiling rose to switch carrying live (brown) + switched live (blue with brown sleeve); b) 3 way (new colours)/earth from 1st floor switch to ground floor switch.

I can work out the connection diagram but have two questions:

1. Is there a preferred way of using the colours in the 3 way cable ie. which is the switched return?
2. What is the correct way to connect the switched return from the ground floor switch to the switched feed to the rose (blue + brown sleeve) in the wall box behind the switch? The old wiring had one of those screw-on "hats" - which I've lost.

Hope this makes sense, (and yeah it's all gonna get checked and signed off by a sparks!).

Thanks, David.

[Martin]

Not sure if there's a "standard", but IIRC it's usually yellow. In any event, I'd put brown or red sleeve on each of the 6 ends.

Again, not sure what regs say, but I would just pair up each of the two "non-yellow" wires with one of the two feeds from rose - thus two wires in each screw-hole thingy. Each copper core is only 1mm (or sometimes 1.5mm) so should fit easily.

Clever bit is ensuring light is off when both switches are "off" or both "on" - if you care for that kind of symmetry...!!

Sensible that you're going to get it checked if you have any doubts.

[cj]

Hi Dave. Re your problem You say you have 2 cores +earth from ceiling rose to landing switch and

3core +earth from landing switch to downstairs switch. If this is the case wire up as follows:- Look at switch and you will see 3 connections com, L1 , L2. Downstairs connect 3 wires one to each (their is no hard fast rule for new colour code yet) .I use brown comm , L1 grey , L2 Black. Upstairs connect the colours the same. Now take the twin brown feed wire from the rose (in your case brown/blue) and put one core in each of L1 and L2. Job done No need for connectors or anything . BTB if you want symetry of switching just change the wires in L1 and L2 at the downstairs switch if not correct.

HTH

CJ

[Dave Plowman (News)]

You don't need any connector blocks etc - see below for the preferred way. You'll need to set your newsreader to a fixed font to see the diagram properly.

L1 L1 0===========0 0===========0============= Line | \\ / | C 0================================O C \\ / \\ / 0===========0 0===========0============= Switch return L2 Optional L2 Intermediate

[Fash]

Surely the best way to determine colours is to look at what has been done elsewhere in the installation using old colours and then do a 1:1 map onto the new colours as defined for 3 phase wiring. This would mean that:

Red = Brown Yellow = Black Blue = Grey Black = Blue

This way you should have consistency between old colours and new colours at any point in the system and no-one should have a problem.

Regulations don't specify a particular way but as a previous poster said all lives/switched lives should be marked with brown tape or sleeving.

Fash

[DavidM]

Thanks to everyone - simple when it's explained :)

So since all the cores in the 3 way cable are potentially live, depending on the switches, both the Grey and Black should have brown sleeves at both ends. I'll assume that unless anyone says otherwise.

David.

[Andy Burns]

remember, there is no yellow

new colours for 3&E = brown/grey/black, not yellow/red/blue

[Martin]

Thanks - yes, I overlooked that. Mind you, aren't many of us using old cables to conceal evidence that they've been installed since new regs came in :-)

[Andy Burns]

YMTTICPC

[Tim S]

Pardon? Not come across that before, pray tell, what does it mean?

And before you ask, google gets 4 hits and none a definition.

Cheers

Tim

[Martin]

You may think that... I couldn't possibly comment.

Actually, if you click on first link, it's a thread containing the mnemonic, followed by WTFDTM ("what ** does that mean"), followed by the answer...!! (Yes - it had me wondering, too..)!!

[Martin]

ROFLMAO

[Andy Burns]

Actually if I'd abbreviated the quote properly as YMVWTTICPC then Google would have provided zero hits