controlling floor lamp with standard light switch

[flippet]

I'm hoping to change an existing 1-gang light switch to a 2-gang switch controlling both the existing light and a mains powered floor lamp - will try to explain how, and would welcome any opinions/advice!

Below the light-switch is a 2gang ring-main socket. If I run a 3A fused spur to a single socket for the floor lamp, then 1.5mm twin core cable back to the light switch I think it should be fine to wire into the second gang alongside the standard light switch, correct?
My only concern is that somebody in the future may not figure the spur is wired into a standard light switch and swap out the 3A fuse for a 13A to power some appliance. Is this a genuine concern?

I realise I have a few options: I could cut out a 2nd hole or extend the hole for a 20A rated switch, but really had hoped to use a simple 2g faceplate in style with the room's other fittings - which is also the reason I'm avoiding modular options.

I'm also considering cutting the plug off the light and wiring it into the lighting circuit, but then it's not easily movable if the need arises. Perhaps still the best solution, I don't know anymore, my mind seems to go round in circles!

 

[JohnW2]

I'm hoping to change an existing 1-gang light switch to a 2-gang switch controlling both the existing light and a mains powered floor lamp - will try to explain how, and would welcome any opinions/advice! ...Below the light-switch is a 2gang ring-main socket. If I run a 3A fused spur to a single socket for the floor lamp, then 1.5mm twin core cable back to the light switch I think it should be fine to wire into the second gang alongside the standard light switch, correct?
My only concern is that somebody in the future may not figure the spur is wired into a standard light switch and swap out the 3A fuse for a 13A to power some appliance. Is this a genuine concern?

If you use a 2A or 5A round-pin socket for the light, then no-one will be able to plug a 13A plug into it.

The only other concern about what you are proposing is that it will mean that there will be electricity supplied by two different circuits going to your new 2-gang switch. People working on that switch in the future might not realise that they need to isolate two circuits to make it 'safe'. It's probably not very practical, but it would be better if you could supply the floor light socket from the same lighting circuit as that involved with the other half of the 2-gang switch.

Kind Regards, John

 

[flippet]

2A round-pin plug & socket - I had no idea they existed, that's a great solution, thank you John.

I hadn't even considered the circuit isolation issue - 1000 potential customers out there ought to be grateful I never tried to become an electrician!!

 

[JohnW2]

2A round-pin plug & socket - I had no idea they existed, that's a great solution, thank you John.

You're welcome. It might be 'better' to use a 5A one - since otherwise some may argue that a 2A one is not adequately 'protected' by a 3A fuse in your FCU!

I hadn't even considered the circuit isolation issue - 1000 potential customers out there ought to be grateful I never tried to become an electrician!!

Do you intend to attempt to address the issue? The 'simplest', although far from ideal, solution would be to put a 'notice' next to the switch to warn people of the need for 'two-circuit isolation' before working on it - but I suspect you would not want your living room (or whatever) 'adorned' by such a notice! As I said, I think the only other solution would be to run the round-pin socket for the floor light (via a switch) from the lighting circuit (in which case you probably wouldn't need an FCU) - but, unless you are pretty lucky, you will not find all the requisite lighting circuit wires (neutral as well as live) present at the switch. Another option, of course, would be to abandon the idea of having the new light switch as you have conceived - but, instead, to have a switched FCU running off the sockets circuit (as you propose) feeding your round-pin socket and use the switch of that FCU as the means of turning the floor light on/off.

Kind Regards, John

 

[flippet]

Sorry I didn't explain properly - as soon as you mentioned the round-pin socket I thought that would be ideal for wiring up to the lighting circuit...otherwise even if it were just for myself I'd probably forget to isolate both circuits at some point down the line, let alone whoever owns the house in the future!

I've got a 3-core wire coming from the light down the wall from the attic to the switch, and then twin-core continuing the circuit from the switch down the wall, behind the double socket and on to the downstairs or back to the fuse panel (I lose track of it then).

So anyway it should be easy enough to run another twin core between the new 2g switch and the round-pin socket and both will be properly switched on the same circuit. And I shouldn't need a fcu if I'm just coming off the lighting circuit - is this correct?

 

[JohnW2]

Sorry I didn't explain properly - as soon as you mentioned the round-pin socket I thought that would be ideal for wiring up to the lighting circuit...otherwise even if it were just for myself I'd probably forget to isolate both circuits at some point down the line, let alone whoever owns the house in the future!

Fair enough - but the use of a round-pin socket obvioulsy does not, in itself, solve the 'double isolation' issue. However....

I've got a 3-core wire coming from the light down the wall from the attic to the switch, and then twin-core continuing the circuit from the switch down the wall, behind the double socket and on to the downstairs or back to the fuse panel (I lose track of it then).

That's still not totally clear (at least, not to me) - although it sounds as if you may well have the required neutral and live of the lighting circuit there at the switch. Would it be possible for you to provide a photo of what's going on inside that switch (with power switched off, of course!?.

So anyway it should be easy enough to run another twin core between the new 2g switch and the round-pin socket and both will be properly switched on the same circuit.

Yes, provided that (as above) you have both L and N of the lighting circuit available at the switch.

And I shouldn't need a fcu if I'm just coming off the lighting circuit - is this correct?

If you used a 5A socket and had a 5A fuse for the lighting circuit in your 'fuse box, that would certainly be true. If (as is probably more likely) you have a 6A MCB for your lighting circuit, a few might quibble about use of a 5A socket without an FCU, but, if I dare to say it, IMO that really would be 'splitting hairs'!

Kind Regards, John

 

[flippet]

It's definitely neutral and live - whoever wired it up used a 3 core from the light, switching between live and 'hot' with neutral wire bypassing the switch entirely via a terminal connector to the continuing circuit.

Thank you again for the advice, it should be easy now to wire into the lighting circuit and avoid the ring-main entirely.

With regards to the FCU, I guess it won't cost much more time or money to use a dual dry lining box and fit one next to the round-pin socket, even if it's not strictly required, so thanks again for mentioning it.

Edit: just re-read my post and to avoid confusion the existing switch doesn't switch *between* live and hot, it's a 1-way switch so it just breaks the connection between live and 'hot' live (not sure of the terminology sorry) leading back to the light. Not really important anyway.

 

[JohnW2]

It's definitely neutral and live - whoever wired it up used a 3 core from the light, switching between live and 'hot' with neutral wire bypassing the switch entirely via a terminal connector to the continuing circuit. Thank you again for the advice, it should be easy now to wire into the lighting circuit and avoid the ring-main entirely.

Great - it sounds as if you're in business, and know what you have to do.

With regards to the FCU, I guess it won't cost much more time or money to use a dual dry lining box and fit one next to the round-pin socket, even if it's not strictly required, so thanks again for mentioning it.

To be frank (although I don't doubt that someone will 'shoot' me for saying this) from the point of view of having a '5A' socket protected by a 6A MCB, I personally wouldn't bother about the FCU. More to the point, however, is that the cable of your floor lamp may possibly not be hefty enough to be protected by a 6A MCB - it would have to be at least 0.75mm² cable for that. However, if the lamp's cable is thinner (e.g. 0.5mm²), then I believe that you can get fused '5A' round-pin plugs - in which case you could presumably put a 3A fuse in it and solve that problem (without an FCU). It's up to you.

Kind Regards, John