In article ,
JohnB wrote:
Anyway the one we have in the house has gone pear shaped and the missus
wants to keep it and got a new one from B&Q. Instructions are useless.

The old one has 2 connections one marked "Com" which has the thick red
wire and one of the thin red wires connected; and one marked "L" with
the other thin red wire connected, - usual earth to face plate.

Is there another switch close by? The second wire connected to 'com'
probably goes to this.

The new one has 3 connectors L1, L2 & then another with a strange symbol
on it - as far as I can glean from the instructions it is for a
transformer (?) - low voltage supply ?

L1, L2 and common are the standard three terminals of a two way switch,
and many dimmers do actually have a two way switch fitted. I'd just treat
the one with the strange symbol as 'com' - and even although it's designed
for low voltage lighting it will be ok with normal. No 'low voltage'
dimmer actually works on the low voltage side - they are simply of
different (more expensive) design to cope with the inductive load, but
will work ok with a normal one.

Have we got the "wrong" dimmer switch ? If not how should I wire it up.

--
*When the chips are down, the buffalo is empty.

Dave Plowman London SW 12
RIP Acorn