Running 16A outlets off a Radial

[RickH]

I have a 20A mcb supplied radial circuit for my garage.
I would like in place of one of the twin 13A outlets put in a single industrial 16 outlets.

Physically all easy enough to achieve ... intent was to put a 20A dp switch on one side of a dual socket box, and a blanking plate on other with industrial socket fixed onto that blanking plate.

Then thoughts kicked in ... fuse discrimination ? ........... as the outlets is then 16A .. and it is fed from a 20A mcb, do I need to fuse this outlet, and if so how do I achieve this ... fused spurs units only take up to 13A cartridge fuses.
How (assuming I need to) do I fuse ? ..........

I suppose a simple way would be to change mcb to 16A ... but that does lose me the capacity to run multiple outlets up to 40A ... in practice probably not an issue.

 

[Taylortwocities]

Run separate circuit for the 16A Ceeform

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

 

[electronicsuk]

If it were a 20A radial then you could do exactly as you wish, as there's a reg (sorry, number escapes me right now) that allows a 16A ceeform to be fed from a 20A circuit. However, this only applies specifically to the 16A variant and circuits of no more than 20A. In your case the best bet would be to run a new 16A radial as suggested by TTC. Failing that, you can feed a 16A outlet from a 13A FCU with the obvious limitation on maximum load.

 

[RickH]

Run separate circuit for the 16A Ceeform

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

It's an option ... but I don't want to do that .. it's a brand new build, and don't want to start hacking walls about.

 

[electronicsuk]

Run separate circuit for the 16A Ceeform

Meerkat

• Taylortwocities
• 11 Dec 2009
• 53

Simples!

It's an option ... but I don't want to do that .. it's a brand new build, and don't want to start hacking walls about.

In a garage? If you mean in terms of running circuits back through the house, then why not bring the 40A radial into a DB in the garage and down onto your individual circuits from there?

 

[RickH]

This is an integral garage built into house, any additional wiring now would mean chasing into wall ... which I don't want to do.

Perhaps I have 2 options ....

a) I leave mcb as 20A, and put in 16A socket via DP switch (in place of one of the twin 13A) does this meet regs?... if as you say it allows for 16A sockets to be on a 20A mcb (easiest by far if it complies)

b) Change MCB to 16A .... ? I have a number of 13A outlets .. but hardly ever use more than one at a time.


The 16A outlet is for very occasional use of a compressor & welder that need a 15A feed.

 

[electronicsuk]

a) I leave mcb as 20A, and put in 16A socket via DP switch (in place of one of the twin 13A) does this meet regs?... if as you say it allows for 16A sockets to be on a 20A mcb (easiest by far if it complies)

Not sure how this would be leaving anything as-is. You told us earlier that the MCB was 40A. If it is indeed 20A, fire away and feed the 16A outlets directly off the radial circuit.

 

[RickH]

Sorry ... my error ... thinking so much about 4mm2 t&e today that I wrote 40A ... it is in fact a 20A mcb feeding the radial circuit.

There are a few double 13A outlets, a couple of fused spurs.

What I want to do is add one Industrial 16A outlet instead of a double socket.
Is this permissible ? ........ in theory you could draw a full 20A from that outlet and plugs only rated at 16A ? ..... that was my concern.

I don't want more than 16A ... just want to know if this complies.

I have updated first post to correct mcb value. .

 

[electronicsuk]

What I want to do is add one Industrial 16A outlet instead of a double socket.
Is this permissible ? ........ in theory you could draw a full 20A from that outlet and plugs only rated at 16A ? ..... that was my concern.

You're right, it would permit overload, but believe it or not it is permitted somewhere in BS7671. I really hope I haven't just imagined the reg. Hopefully someone who's had less beers than me right now will be kind enough to come along and post the reg number.

 

[ColJack]

providing that the cable is suitably rated for 20A then there is no problem putting a 16A blue ceeform on it.

the item itself will be limited to less than 16A, or it shouldn't have a 16A plug on it..

if it's a DIY plug fitting and it draws / is rated at more than 16A, then a 32A plug should be used with the corresponding socket. ( assuming of course that it's not rated exceeding 32A )

after all, your average double socket is rated only for 13A total, not 13A each ( depending on the manufacturer, some say up to 20A, but still not the full 26A that you can get through one ).

 

[ban-all-sheds]

Actually all double socket outlets have to be capable of delivering 20A in total - it's in the BS 1363 spec.

MK for one make theirs capable of passing 26A.

intent was to put a 20A dp switch on one side of a dual socket box, and a blanking plate on other with industrial socket fixed onto that blanking plate.

Why not just fit a switched socket like this:

 

[RickH]

>why not fit ....

only because a dual socket box was already in place.

 

[ban-all-sheds]

You've got flush sockets in your garage?

 

[RickH]

yep .... it's an integral triple garage in the house .... all light switches & power outlets are flush fitted ... and all walls, floors & ceiling are fully insulated.
Doors are also insulated and sealed all round.

That is why I did not want to add any wiring.

I also have a double external garage & 'barn style' boat shed, though here all sockets & swicthes are surface mounted.

It's a big self build ... been a long time doing this, couldn't afford to buy it.

 

[ban-all-sheds]

OK.

Sockets like that are larger than a standard double BS 1363, so you could remove the socket face, fix one over the hole and feed the cables in from the rear.

That type have a useful feature of the switch and plug being interlocked. There's a cam inside which engages on the plug, and you cannot insert or remove the plug unless the socket is off, nor turn the socket on unless there is a plug in it.

I'd advise installing one.