Electricians: Installing Plug Socket In Loft

kingy666 said:
But, this is a house we are talking about so the 1mm twin and earth that feeds the lighting circuit is more than likely enclosed in the wall and so, using the regs, the current carrying capacity is 10/11 Amps.

Can i ask how many sockets you have wired off a lighting circuit in your time as a spark?
Click to expand...

That would still satisfy Ib <= Iz <= In as 6A fusing. (hope that the right order lol but you see what i mean)
 
Sorry if i came across as a bit arrogant but as a spark i would never want to give someone bad advice. Trying to give electrical advice on the internet can be a bit difficult as you can't gauge how good the person is at DIY that you are giving the advice to and things can so easily go wrong.

I don't have a copy of the regs with me (i don't sit at home every night reading it :D) but i did get the current carrying capacity from here

http://www.cable-ratings.co.uk/

You can even see that 1.5mm twin and earth is rated at 13A (when enclosed in a wall) but if you have a 13A socket and on top of that you have 3A worth of lights attached to that lighting circuit then you will have a load of 16A (3A over the rating of 1.5mm cable).
 
Last edited:
Np i didn't take offence, actually its getting my post count up, so thx v much :)

cool site, bookmarked :)

I think we might be misunderstanding each other when talking about 13A socket on a cable that potentially cannot take 13A.

What iam saying is as in the formula above (which maybe the wrong way around so i will type it out long style)

That..

That capacity of the cable must be greater or equal to the rating of the fuse

The fuse must be greater than or equal to the design current of the circuit.

If those things are true the cable will be perfectly safe, and the circuit will operate correctly, barring any faults.

This is if you do not rate to 13A socket at the full 13A as that would increase the design current, but in this case it is probably only going to have less than 1A load plugged in, this is a strange example to apply this formula to so it creates this problem.
 
Last edited:
But a 13A socket is designed to take a standard British 3 pin plug which can have any 13A appliance plugged into it. So, even if you believe you will never plug anything in more than 1A there is the possibility someone will plug a mains powered 3KW, 18" black mamba vibrator into that socket (:D). This would mean that a 13A socket should never be used on a cable only rated for 10/11 Amps. But you can get 5A round pin sockets/plugs but that could be a whole new discussion (I have never installed them as i mostly do commercial work these days).

Edit: Go on HardwareGeek, get that post count up so you can access the members market.
 
Last edited:
i see that but what im saying is that even if that did happen, too much current drawn for the circuit, barring any failure of the mcb, which is another issue, it would just be an inconvenience issue / practical reason not to do this, rather than a safety or regulation reason not to do this etc

(Baring any safety issue caused by loss of lighting in the property etc)

As the mcb would operate at 6A+, according to its fusing characteristics, so it would just trip the circuit, not allow the circuit to run too hot and burn out etc.

EDIT: Thx mm here i come lol, more interested in free postage / shipping tbh :)
 
Lol, we could go on all night with this. The OP did not state if he has MCB's and an RCD or an old wylex fuseboard with rewirable fuses which i think than changes all calculations for cables if i remember correctly (It is nearly 20 years ago when i did my City & Guilds). Having an RCD is also another debate as the OP could have a split load consumer unit in which the lighting circuits are not protected by the RCD but the other circuits are then if you wire a socket off the lighting circuit then this socket will not be protected by the RCD.
 
BS3036 rewirables mean you have to use a 0.75 factor in the equation somewhere, forget exactly, but i agree its getting late lol, enjoyed talking to you tho

Post back if you find out an answer tomorrow tho, i would like to know, right or wrong i will learn something.
 
I don't need to post back tomorrow as it is wrong to wire a socket into a lighting circuit.
I think our discussion should be shown to most people who suddenly think 'I know i will wire an extra socket in this room, it will be easy'.
Now thats it. Close this thread. :D
 
Last edited:
LOL - as a DIY noob who has temporarily installed sockets in all kinds of silly places - I found it really interesting to read your posts. Especially as I am considering a change in direction career wise.
I would probably have just put a junction box on the highest amp ring I could find and run a spur off it to one of those fancy dandy seperately fused sockets if I could have been bothered!
Good to see that those quals really mean you have to understand the safety side of things.
 
HardwareGeek said:
In fact there was a recall recently when electrium manufactured 6/10/16A Breakers that didn't trip until over 40A if i remember correctly. Thousands of mcbs were installed all across the country, and may even be in your house right now if you had work done before it was discovered.

Went to a job recently where this happened and it literally melted half the board and i had to replace it.
Click to expand...

It wasn't that they didn't trip, more that the contacts inside did not meet together as firmly as they should, resulting in a high resistance connection within the breaker which casued burning to the breaker itself, depending on exact circumstances (load etc), most of these breakers did trip eventually from the heat travelling back into the thermal overload part and casuing it to operate, but not before in a lot of cases browning off the side of the breaker, or in extreme cases melting the board and surrounding breakers!

There was a recall campain, but there are still some out there!
 
Your best bet would probably be a 5amp socket with the round pins tapped off the light circuit . At least someone can't come along and plug a 13 plug in.
 
Started a bit of a debate here. I've had to change by plans a bit and now require several sockets fitted in a couple places so I decided to place an advert on myworkman.co.uk for quote haven't had any yet. Any recommend a good site for getting quotes etc.

Cheers
 
PistolPete said:
I'm sure Ban All Sheds would be first to comment on this if it were posted in Diynot.com
Click to expand...

It just feels odd reading an electrical thread without his "i'm right you're wrong, your going to die bcause you clearly don't know anything and anyone getting solar panels through the FIT scheme is killing old people in the winter" malarkey.
 
Threads like this make me :(

so much bull **** it unbelievable.

You can take power from any cct even lighting **BUT** it must be fused down by a fused spur to 3/5A.

Get a sparks in for the sake of £50 I would rather know its done correctly.

As one of the guys said at the start you can break into a ring (who ever the poster who mentioned a lighting ring, please refrain from posting in electrical threads again.) and have a the socket wired into your upstairs sockets, which is the correct and best way as there will be no spurs added.

Again I believe electrical threads should be banned.
 
As an retired electrician I cannot believe some of the people on this forum saying it is OK to wire a 13 amp socket into the lighting circuit.
Even a spur of the ring main has a maximum length on the run of wire used, and if you are not confident enough to do the socket yourself, pay for an electrician.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom