2 gang switch 2 lights in kitchen

[Bennyboy1974]

Hoping someone can help explain the wiring on my switch in the kitchen.

I have just replaced a metal 2 gang switch in the kitchen/diner to a plastic white one and all is working fine, I just wanted to understand how the circuit works.

One switch operates the light fitting at one end of the kitchen and the other switch operate 4 spots at the other end of the kitchen.

Going down into the backbox are 4 sets of twin and earth wires.

• The 4 neutrals are all terminated in a chocbox
• The 4 earth wires are also terminated together
• The 4 red lives are as follows:
• SWITCH1: ( 1 live to COM (L1), 1 live to L2)
• SWITCH 2: (1 live to COM (L1), 1 live to L2)
• there is then a small link between COM on switch 1 to L2 on Switch 2.

If anyone could explain why 4 sets of wires and what they all mean in relation to each other i would appreciate it?

Thanks in advance, all the best. Ben

 

[Meggerman]

Hi Benny. The cables you have here are: (I have tried to explain I layman's terms)

1. Live in (this is coming from the distribution board or another point further up the circuit)
2. Live out (this goes on to supply the next point on the circuit if applicable, this is why it is linked across between terminals)
3. Light 1
4. Light 2

1 & 2 are power feeds only, Live & Neutral, and it feeds the common terminals.
3 is a light fitting/s connected across a switch
4 is another light fitting/s connected across other switch
When you switch on, you connect live to power your light fitting

The neutrals are all connected together to complete the circuit.

The earths are all connected together which goes back to the main earthing terminal at your fuseboard.

 

[Bennyboy1974]

Perfect, thank you very much, that makes sense. Am so used to replacing a switch and just seeing a few wires to change, so was a bit baffled when i saw 12 wires staring at me! Thanks for the great explanation

 

[Bennyboy1974]

Hi,
Just out of curiosity why is it all four cables go down to the switch when in other parts of the house, the Live in/out go to and from the light and then a single cable runs from the switch to connect?

 

[Meggerman]

Hi,
Just out of curiosity why is it all four cables go down to the switch when in other parts of the house, the Live in/out go to and from the light and then a single cable runs from the switch to connect?

Both are perfectly valid. The other method you are referring to is the loop in method where you just have switch wire at light switch. This uses less cable, works fine with pendants but can be quite tight on modern fittings sometimes. The fed switch method (as yours is) means you end up with a single switched live and neutral at light fitting which is much easier for modern light fittings and can avoid having junction boxes in ceiling voids when installing spotlights.

 

[Bennyboy1974]

Great response and helps me understand now. Now that i understand that both methods are valid, it puts my mind at rest.
Cheers.