Holder Dimmer Switch

[riveralt]

Via the internet I am trying to help a friend swap a standard two gang two way rocker switch for this Holder two gang two way dimmer switch - which has 5 terminals instead of the normal 6. There is a single common L.

Holder Dimmer Switch instructions

• riveralt
• 19 Jul 2015

The two gang dimmer is sited in the hallway with gang 1 linked to a single rocker landing switch and both operate the landing light.
Gang2 controls the hallway light.
Both the landing and hallway lights are on their own RCD protected circuit.
As I read it if the circuit is wired as per the instructions for the two way circuit - then for the one way hallway circuit I only need a switch live into the LHS arrow 1 - but won't that create a borrowed neutral? Won't putting the hallway live loop into L and switch live arrow 1 create the same situation?
I thought of wiring the two way circuit using the 'standard' method Live loop = L1 Switch Live = L2 then using the three strappers - but the Common L on the Holder switch will still cause the problem.
If this is correct, aside from putting both lighting circuits on the same mcb, has anyone got an idea how I can remove the potential for a borrowed neutral.

 

[davelx]

As you suggest, since the 2 dimmers have a common L terminal, there is no way (without some tricky and possibly, impossible, modifications) you can use that to control lights on two different circuits without creating a borrowed neutral.

AFAICS there are two alternatives:
(a) run a neutral from the circuit providing the L feed to the lamp on the "other" circuit, thus putting both lamps onto the same circuit (but I'm sure you realise that).

and

(b) get a different dimmer!

 

[ban-all-sheds]

Via the internet I am trying to help a friend swap a standard two gang two way rocker switch for this Holder two gang two way dimmer switch ... The two gang dimmer is sited in the hallway with gang 1 linked to a single rocker landing switch and both operate the landing light.

Have you pointed out to your friend that he will not be able to control the level of brightness of the landing light from the landing? i.e. if he uses the switch there to turn it on and it is not at the level he wants he will have to go downstairs to use the dimmer switch in the hall, and then go back upstairs?

If he must have the landing/stair light on a dimmer then he would be foolish not to use a master/slave dimmer combination so that he can control the brightness from both locations.