2 way switching configuration HELP

DaveChase · Oct 25, 2018

Good evening All,

After perusing the forum as a visitor for a while I have now found the need to ask you ladies and gents for your help and advice.

I have a customer with 2 way switching controlling the 1st floor landing light, it consists of a 2 gang switch downstairs (hallway & landing) and 1 gang upstairs, standard.

The problem is that the downstairs switch has been removed with intent to replace it with a decorative one and I cannot work out how to wire it back up.

It is not what I know as 'standard' 2 way wiring....

Upstairs switch (untouched) has -

(2 x neutrals in a connector block),
3 x reds in L1,
2 x blacks in L2,
1 x red in COM.

Downstairs switch has (all now disconnected) -

Downstairs light (1 way) -
1 x red
1 x black

Spare (all now disconnected) -
1 x red
1 x black

He also mentioned there was a piece of red wire about 1 inch long in the switch that hedropped....would this be a bridge of some kind?

littlespark · Oct 25, 2018

I take it this is wired in T&E? if so, which red goes with which black as it disappears into the wall at each switch?
You'll need to dead test the cables, work out what goes where by drawing a diagram.

I know what you mean by non 'standard' 2 way.... There's no 3 core&E which helps.

The red link will be needed.

DaveChase · Oct 25, 2018

The downstairs switch seems to be t&e, one for the hallway light (1 way) and one for the upstairs light (2way) I can get it so that they both work from downstairs in a 1 way set up (red/com & black/L1) but the upstairs switch has what looks like 2 x 3 cores and 1 x t&e.....

Sintra · Oct 25, 2018

Any chance you could add a photo of both switches.

chris gray · Oct 25, 2018

DaveChase · Oct 25, 2018

[ElectriciansForums.net] 2 way switching configuration HELP

DaveChase · Oct 25, 2018

Richard Burns · Oct 25, 2018

It sounds like you have two wire two way switching but someone has used the cpc as a neutral.
I think you should start working out how to wire it safely with the existing cables used correctly, which should be possible but does depend on the split of circuits of the lights whether you can cross over.

chris gray · Oct 25, 2018

Sintra · Oct 25, 2018

Is that single red in the upstairs switch part of a 3 core?

littlespark · Oct 25, 2018

If there were 3 cores in there, you'de have yellows and blues to think about.
They've maybe used a twin as strappers….

Looking at the pic.... is there only one cable there with an earth wire?
It should be sleeved.

In the 2 gang switch, is one of them a 2 way?
A 2 way switch needs a cable in each of the 3 terminals.

TJ Anderson · Oct 25, 2018

Just work it out with a continuity testers between line cores and earth if you are unsure. It is a basic 2 way circuit but has the feeds and loads also in the switch. Still same principles.

Identify your common and strapper wires. Terminate common to common. That's two terminations done. Terminate strappers...that's 4 more done. Neutrals already terminated. Now what you are left with are feed and load wires. Feed on L1, load on L2....or vice versa if you like
That link on the downstairs is to link the feed which will be on your feed strapper to common of the one way for the downstairs light (so it has a feed)