Help wiring switch please

[chris_s1]

Sorry for this obviously newbie question but I have looked at the for reference section and either didn't find the answer or didn't know what I was looking at!

Anyway, I have two wall mounted lights in the living room, currently controlled by a single ordinary switch in a really badly positioned place. In stead of moving the switch, I am fitting a remote dimmer.

The wiring to the current switch is shown in this picture:

Where the reds go to 'L IN and L OUT' and the blacks go to 'N IN and N OUT'

My new switch has just live, arrow/squiggle and S

At each light on the wall there is just a red black and earth emerging from the wall into the light units.

I have tried connecting both reds to LIVE and both blacks to arrow but when I do this the lights are permanently on.
I tried connecting one red to live and the other to arrow but nothing happened.

Any help greatly appreciated.

PS I have just moved into this house and have no idea what kind of electrics are installed. Does this mean I have a JB type? House is about 20 yrs old...

Many thanks
Chris
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[Spark123]

It looks like the neutrals are looped into the back of the switch. Is this fed from the lighting circuit, is the switch in the pic a switched fused spur unit or just a double pole switch?

I have tried connecting both reds to LIVE and both blacks to arrow but when I do this the lights are permanently on.

Doing this, if you have connected live to one side and neutral to the other you have most likely blown the dimmer.

 

[chris_s1]

Yes it is a fused unit rather than a regular switch.

 

[Spark123]

Is it fed from the ring main?

 

[chris_s1]

I'm not really sure, but the switch is down at knee level where you would expect a socket to be....

 

[Spark123]

I take it that it is all back together as was now, switch the wall lights on and when you turn off the socket circuit do the wall lights go out?

 

[chris_s1]

Yeah it is back as was now and is working as before. Switch correctly controls power to both lights

 

[Spark123]

When you isolate power to the socket circuits only, do the wall lights still work?

 

[chris_s1]

Checking...

 

[chris_s1]

Yes its on the ring main not the lighting circuit

 

[Spark123]

You need to keep a fused spur in position (3A should be ok) as the fuse is protecting the wall light circuit and install the dimmer switch between the fused spur unit and the lamps.
You will also probably find your dimmer switch is now broken.

 

[chris_s1]

I was worried you were going to say that!
Does the fused spur switch have to stay in place or can I use some kind of in-line fuse and fuse holder? I'm trying to avoid cutting another hole in the wall...
Where would I wire the dimmer, in the live feed in series (or in place of) the current switch?
What are the two neutrals doing in this switch? Are they connected when wired to the N in and N out terminals on the fused spur?

Thanks

 

[ban-all-sheds]

Keep the FCU, move the cable attached to OUT to the dimmer, and run a new length of twin & earth between the FCU and the dimmer.

At the dimmer connect the two blacks together with choc-block, and put the two reds into L and ~.

Obvious caveats apply - turning off the power, maintaining earth continuity...

 

[ban-all-sheds]

I was worried you were going to say that!
Does the fused spur switch have to stay in place

Yes.

or can I use some kind of in-line fuse and fuse holder?

No.

I'm trying to avoid cutting another hole in the wall...

Can't be avoided.

Where would I wire the dimmer, in the live feed in series (or in place of) the current switch?

In the live conductor between the FCU and the light.

What are the two neutrals doing in this switch? Are they connected when wired to the N in and N out terminals on the fused spur?

Yes - it's a double pole switch. They are there because the light needs live & neutral - where else should they be?

 

[chris_s1]

Thank you both very much for your help. I know now what I need to do.

Cheers
Chris