Replacing dimmer with rocker - wiring dilemma.

[Edward]

I'm trying to replace an old dimmer switch with a normal rocker switch.

Having taken off the faceplate, I see that there are four cables coming into the backbox, two from the left, and two from the right.

All the black wires are connected to the same terminator block.

From the two cables on the left, the two red wires are connected to the L2 connector on the dimmer switch.

From the two cables on the right, the two red wires are connected to the "Variable Load" connector on the dimmer switch.

There are two green cables going to earth in the box.

In the new rocker switch there are three connections:

Common

1 way 2 way

Which reds go where, please?

Many thanks

Edward

[ARWadworth]

The two reds that currently go to L2 on the dimmer go to the Common on the new switch and the other two reds go to L1 on the new switch.

It really will not matter if you did it the other way around, it will still work.

Cheers

Adam

[Kevin]

two reds from l2 to common, two reds from variable to 2 way, blacks and green remain the same

[terry]

[terry]

Since you have it apart and with the circuit breaker OFF;

1) Leave as is. The blacks go on through to the lights. 2) Connect these two reds to Common. It's the live feed from the fuse or circuit breaker. 3) Connect these two reds to 1 way. This is the switched feed to the lights to the lights. 4) Leave earths as is connected to box. All connections tight and proper. PS. Don't attempt any other wiring without help!

[Spamlet]

As I like the brass push button on/off of our dimmers, but got fed up with changing them far too often, I have taken to bypassing the dimmer part of the circuit and just keeping the switch. Nicer than a rocker, and it still matches the rest of your not yet blown dimmers. Not something for everyone to try though.

S S

[Edward]

Many thanks to all for your help. Now successfully wired up and no-one dead yet! I may be back as there are some three way switches to replace in due course!

Edward

[John]

I presume you mean 3 gang (3 switches on one plate)

[Kevin]

you might presume wrong 3 way does exsist

[John]

Please explain why a three way switch would be common in a house.

Two way - yes. Intermediate - yes. Double pole - double throw - yes.

I look forward to hearing how a three way switch is used.

[John]

In the UK the terminology is:

Gangs = the number of switches in a unit (three being the typical max on a square plate)

Ways = the number of outputs that can be energised by the switch. Therefore a normal switch is "one-way" as it only makes one connection. A typical staircase light has a two-way switch as the toggle can energise either of two connections.

If you add additional switches to a stair light the switches are 'intermediate' switches and any number can be used - the name remains the same. It is a Double pole / double throw with internal links to give a changeover effect. There are 4 terminals and the connection is in effect either straight through - or crossed over. (it is not a 3 way or a 4 way switch.

[Kevin]

long hall with stairs

is a intermediate not a three way switch? it is in my book, three switches controlling 1 light =3 way switching

[dennis]

Its a two pole changeover switch.

A three way switch may be something like those on electric shutters up-not connected-down.

[John]

is a intermediate not a three way switch? it is in my book, three switches controlling 1 light =3 way switching.

No. So taking your idea if you added 3 intermediate switches it would be 5 way?

Think about the type of switch - not the number of switches used.

[John]

I think it would be a "Two way - Centre off" Three way would need three outputs. What you describe has two outputs and one off position.

[Mike Clarke]

The problem here is that, like Britain and America, we have 2 different communities divided by a common language. To those who have some background knowledge of electrical work your definition is perfectly correct. For the vast majority among Joe Public who have 2 switches for the landing light it's "2 way" because there's 2 ways of turning the light on or off so if there's a third, intermediate, switch then that's 3 way because there's 3 different ways of turning the light on. It's "obvious" to them and that's what they'll call it regardless of the correct technical terminology. No disrespect to the OP who used the term but he was asking for help with some quite basic wiring so it's quite understandable that he'd regard 3 switches for one light as "3 way".

[John]

I can only agree with your observation - however, we should try to get the concept of "Intermediate" switch used more as there is no limit as to how many can be used - so not only 3 ways of working a light. The internet has many US examples and some terrible practices illustrated which would be incorrect in the UK.

I will however stick to my college text books and consider "Way" to mean switched outputs from a "common"

[teddysnips]

Yes, I meant three gang. The upstairs hall light is operable from three different switches, one of which is a single rocker in a bank of three, the downstairs hall light from two. I'll be back when the hallway is decorated for more of your generous sagacity!

Thanks

Edward

[dennis]

Or three way and leave one disconnected.

[dennis]

It would be best to just explain the difference between gangs and ways, maybe? I shudder to think what they think poles are.

Gangs are the number of switches in the plate. Ways are the number of ways a wire can be switched by a switch. Poles are the number of circuits switched by a switch. Not quite technically correct but close enough for house wiring.