Replace light switch for USB socket
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philb1980
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Replace light switch for USB socket

by philb1980 » Wed Mar 25, 2020 11:06 am

I have a light switch above my bed which is a second switch to control the bedroom lights. I do not use it and want to replace it with a USB socket. I have seen that I can buy a single plate with 3 USB sockets (without a 3 pin socket) which I would like to put in (see image). Does anyone know if this is possible? Thanks.
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Mr White
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Re: Replace light switch for USB socket

by Mr White » Wed Mar 25, 2020 5:27 pm

You can change it, but it will not work. (I didn't want to just type "wont work")

philb1980
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Re: Replace light switch for USB socket

by philb1980 » Thu Mar 26, 2020 12:27 pm

Okay, thanks. I guess that is because it is on the lighting circuit?

Mr White
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Re: Replace light switch for USB socket

by Mr White » Fri Mar 27, 2020 11:17 am

philb1980, no it has nothing to do with it being on a lighting circuit.
A light switch only requires two wires. One that is always live, and the other that goes live when you operate the switch. (It is called switched live)
To operate anything else, you need a permanent live and a permanent neutral, you have no neutral. If you open your switch you will find 3 wires, this is because you have what is known as 2 way switching. (You can turn the light on/off from two different places) One is common the other two are strappers, but none will be neutral, and the same at the other switch, none will be neutral.
So as I said your new device will require a neutral, and you have no neutral, so it will not work.

philb1980
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Re: Replace light switch for USB socket

by philb1980 » Fri Mar 27, 2020 11:23 am

Okay understood thanks

prrichards
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Re: Replace light switch for USB socket

by prrichards » Fri Mar 27, 2020 4:50 pm

Hi

It would be possible, but would depend on how the existing switches are wired. There are 2 common ways of wiring domestic lighting circuits. the first has the determinant line and neutral wired in a " loop" to each light fitting, and a determinant line and switched line running to and from the switch. If the lighting is wired using this "loop" system it would not be possible.
The 2nd method has the line and neutral feed running to the switches, if this s the case then yes it would be possible. Depending on which of the 2 way switches has the permanent feed going to, you may need to re-purpose and label the strappers to carry the line and neutral feed to your new outlet.
Another consideration is the depth of the box box and if it would accommodate your new outlet, you may need a spacer.

So yes it is possible, but as with any electrical work, I would recommend a qualified and competent person to carry out the work and/or advise on electrical projects.

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Re: Replace light switch for USB socket

by ericmark » Sat Mar 28, 2020 4:38 am

@Mr White has given the right answer, OK there are some odd systems where neutral is provided, and where the cables for the second switch go through the ceiling rose, but this is unusual, normally the second switch of a two way switching arrangement is wired to the first switch directly so the possibility of altering the wiring to do what you want is very slim.

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Re: Replace light switch for USB socket

by prrichards » Sat Mar 28, 2020 6:31 am

It was the "old way" to run the neutral to the switches, but with the increased use of downlighters, it is becoming much more common again. It is simply not possible to give a 'yes' or 'no' without seeing the cables in the switches. in one scenario it is possible, in the other it isn't. The description says images attached, but I am unable to view them (says I do not have the correct permissions)

Mr White
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Re: Replace light switch for USB socket

by Mr White » Sun Mar 29, 2020 12:02 am

The only image posted is that of the 4 port USB charger faceplate.

You are correct with your assumptions, but as this switch in question is a 2 way switch there is no need for a neutral.
If there is a neutral at the other switch it will need to be tested to establish the fact. If the OP is confident to do this, would he not have done it by now, and so would have no need to have asked the question in the first place.

prrichards
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Re: Replace light switch for USB socket

by prrichards » Mon Mar 30, 2020 8:54 am

possible Solution.... if that is indeed the case, Making the assumption that as it is a bedroom and there would usually be an access able loft space. The 3 core strapper that runs between the switches would probably (but not guaranteed) run through the loft. the strappers could be disconnected at the switch you wish to keep with the perm. line and switch line (the perm. would be moved to the "com" terminal) once "dead" it could be rerouted to the rose "loop" and 2 cores (labelled) could be used to carry the line and neutral to the switch / new outlet.
it all depends how confident you are and much you want that USB charger! lol

I would always recommend testing any electrical work carried out, loose connection cause resistance, resistance causes heat, heat causes fires.

I think between us, every and any variable have been covered now! :)

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Re: Replace light switch for USB socket

by Mr White » Mon Mar 30, 2020 10:36 am

prrichards wrote:I think between us, every and any variable have been covered now!


'fraid not. You have overlooked the obvious.
What you have stated is in theory correct, but as I have already said, if philb1980 (the OP) was confident AND able to test, he would not be asking how to do the job as he would already know how to do the job, since he is asking that means he does not know, and further more has no way to test anything that is done.

And it was you who rightly did say
prrichards wrote: ..........as with any electrical work, I would recommend a qualified and competent person to carry out the work

prrichards
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Re: Replace light switch for USB socket

by prrichards » Mon Mar 30, 2020 11:37 am

then its all covered already, Just offering solutions to problems

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