Figuring out type of wiring method used for existing lighting circuit

[jimjamyaha]

Hi.

I'm trying to figure out what type of wiring system is being used in my house for the lighting so that I can add some more switches to the following lights.

Currently the setup is for :

* Light at top of stairs controlled by one switch on landing and one switch at bottom of stairs (right part of 2 gang switch)
* Light at bottom of stairs is controlled by one switch at bottom of stairs (left part of 2 gang switch)

There are 3 cables (top) coming into the back box of this 2 gang switch. One seems to be for the bottom light, another for the top of the stairs light and the other is just a single red.

A cable exits the box for the adjacent room light.

I've attached a photos showing all of this and shown which red cable is connected to the black terminal block (photo angle is not clear).

I can't figure out why the comms are connected together across the switches?
Any ideas / suggestions welcomed.

James.

 

[Phil]

gromits earth sleeving and conductors identified, well thats more than you usually find

 

[Sintra]

Comms are connected because they are on same circuit.

Perm live into switch 1 linked to switch 2. Then a switched live form switch 1 to gnd floor light and a set of strappers from switch 2 to landing switch.

By switch 1 & 2 i am referring to both sides of the 2 gang switch.

 

[Cj24]

Yeah that's your feed in then they linked across your com which shows they both on same circuit then you have your strappers up to your other sw controlling same light

 

[jimjamyaha]

Thanks for your help guys.

So, I'm planning on adding a switch at the top of the stairs to control the light at the bottom and change the wiring on the existing switch to be two way.

In this wiring system what would be the best method of achieving this - would following the guide (two way light switching) make sense for this setup or have I misunderstood the way the current setup is?

James.

 

[Sintra]

The method illustrated would certainly be the easiest.

3 core + cpc between switches sleeved correctly and connected as shown.

 

[jimjamyaha]

Comms are connected because they are on same circuit.

Perm live into switch 1 linked to switch 2. Then a switched live form switch 1 to gnd floor light and a set of strappers from switch 2 to landing switch.

By switch 1 & 2 i am referring to both sides of the 2 gang switch.

As I've got an enquiring mind I wondered what method is currently in use for two-way with the light at the top of my stairs stairs - as you mentioned there are 2 strappers going up to the top switch from the bottom?

The top switch has it's own permanent live connection - i.e. not fed from the first switch like the method here: two way light switching.

Is it just the same, apart from the permanent live is coming to the top switch from the junction box/celling rose?

Thanks!

 

[Sintra]

The method currently in use is the conventional method of 2 way switching.
ie. Perm live into one of the 2 way switches, set of strappers between switches & a switched live out of second 2 way switch to light fitting.

The method in your link is the conversion method.

You will find that the cable from the top single connection of your upstairs switch is infact switched and not permantly live.

 

[jimjamyaha]

Thanks Sintra for explaining this.

In order to add an additional switch in between the first and second for this existing two way light, when they're wired in this way - would this be possible with:

An intermediate switch - running two-core and earth from L1 and L2 on the bottom switch to L1 and L1 on the intermediate switch and then taking a two-core and earth from the L2 and L2 on the intermediate to L1 and L2 on the top switch?

 

[Sintra]

Yes an intermediate switch can be installed in this way to your existing 2 way lighting.

 

[Cj24]

If you wire this way in twin by having feed in at first sw and sw bak up at second sw am I right in saying you obv don't need a 3core in between you just need a twin, because ain't this method usually done with single

 

[Sintra]

Conversion method

Conventional method

 

[Sintra]

Two way & intermediate switching coventional method

Two way and intermediate conversion method

 

[mogga]

CAN we start a new section name it SINTRA n LENNYS TECKKY PIKKIES??