Crabtree to MK light switch swap

[leedavis88]

I am looking to swap damaged Crabtree light switches to new MK ones. Can anyone advise on correct wiring as terminals are labelled different.

The left switch on the crabtree is for outside lights and the right switch operates the ceiling lights. There is another switch on the other side of the room for the same set of ceiling lights.

I have labelled the wires if it helps.

a & e come from one cable

c & d come from another

 

[boringoldcodger]

The left switch on the crabtree is for outside lights and the right switch operates the ceiling lights

I'm assuming you mean when looked at when screwed to the wall, so in your pictures as we look at the back it's the other way round.

a goes to COM, e goes to 1(1way)
the short red wire goes from COM to COM, so b goes to COM.
c and d go to 1(1way) and 2, it doesn't really matter which way round but if you feel the switch is operating "upside down" then swop them over.

 

[leedavis88]

Thank you. The Crabtree is upside down. Will give this a go. Thanks again.

 

[boringoldcodger]

I probably should've pointed out that, on the Crabtree, L1 L2 and L3 form a switch with L2 and L3 close together and vertically above / below their L1. There's a slightly-off-vertical raised bar which tries to indicate that one switch is to the left of it and the other to the right.

 

[ebee]

Two way light switches can be used as one way or two way as required.
Popular markings are Comm, L1 & L2,

Some makes are L1 for 1 way use but others are L2 instead.

some are marked L1 (instead of Comm) and the other terminals are marked L2, L3.
An intermediate switch has 4 terminals , effectively one of the two terminals at the top is connected to one of the terminals at the bottom at one side then repeated at the other side but when switched one set of terminals change place.

So a 1 way switch has only two terminals and can only be used one way.

A 2 way switch can be used as a two way or as a one way switch.

An intermediate switch can be used as an intermediate or a two way or a one way switch.

There is a least one make of switches in white plastic that has two intermediate switches on one single plate.

There are makes of "Grid switches" that can be built up of different switches and mounted on a grid in a Single box or a twin box.

Have fun

 

[morqthana]

You might want to crop, or re-take, photo #2...