Can I add a single socket for fitted microwave to a spur?

[derwentmax]

I have just bought a fitted microwave and would like to fit a socket into the same kitchen unit to make it neat.
Previously I installed some under cupboard lights supplied by a double socket via a fused spur.
Can I install a new single socket from the existing double socket using the spur box as a junction but bypassing the fuse (connect the new socket cables to the cables from the existing socket leading into the fused spur) ?? Please see my image for clarity.

 

[Chri5]

I take it the main socket that the spur is run from is part of a main ring circuit fused at 30a at the board ?

What size cable was used for the spur feed from the socket ?

What wattage is the microwave ?

What is the wattage total of all lights taken via the spur ?

Spurs off spurs are poor form, for everything the total load should be restricted to 13a and I'd imagine the load of lights + microwave is well below 3000w.

I'd go with replacing the existing fused spur with a MK grid system f/spur x 2- which fit in the same space / box footprint as you already have.

You have then created a spur off a spur, fuse at 3a /700w for the lights and 10a /2300w for the microwave. You then have 2 x visible and accessible points of isolation, one for each device / appliance which is very necessary.

There's maybe some debate on my solution so await further debate

Bits

2 x

1 x

1 x

 

[derwentmax]

Many thanks for the quick reply Chri5!

Yes the main socket is run from a main ring circuit fused at 30A at the board.

For the spur feed from the socket, I used standard 2 core and earth cable that one would find between sockets.

The microwave is 750W.

There are only two strip lights at 20W each leading off the spur.

I take it that you mean the load coming off the socket to the spurs shouldn't exceed 3000w?

So with the solution you gave, in effect i am replacing the single fuse spur with a double one, am i correct? Then I would remove the plug from the microwave and wire it directly into the 10A spur, right? Or would i then wire a new socket for the microwave to the spur?

 

[Aragorn84]

i'm not sure that would comply

Spurs from Spurs are not allowed unless the whole thing is protected by a single FCU as far as i'm aware,

So you could do this:

Microwave socket
^
FCU with 13A fuse -> Lighting system (with another FCU at 3A if required by the lights)
^
Ring Socket

You could probably still use the grid system as chris showed, but you'd need to run the 3A fuse off the load side of the 13A one.

 

[Chri5]

i'm not sure that would comply

Spurs from Spurs are not allowed unless the whole thing is protected by a single FCU as far as i'm aware,

So you could do this:

Microwave socket
^
FCU with 13A fuse -> Lighting system (with another FCU at 3A if required by the lights)
^
Ring Socket

You could probably still use the grid system as chris showed, but you'd need to run the 3A fuse off the load side of the 13A one.

Surely as long as the total f/spur isn't over 13a would that not be acceptable ? Although it would allow the potential to fit 2 x 13a fuses which is wrong (Chri5 answers own question).

Feeder cable from main ring socket in to f/spur rated at 13a for the microwave then from the load side 2 connections (to prevent overloading beyond 13a) 1 x cable from microwave and 1 x feeder to 3a f/spur for the lights all on a double f/spur would work.

Messy and I'm not sure if it would meet spec, anyone ?

If you wanted the microwave via socket then run a cable between the 13a f/spur and a socket at the location required.

 

[derwentmax]

Thank you both.
So is this the soloution as I understand it?:

Is this correct and legal?

 

[Aragorn84]

So long as the 3A FCU is attached to the LOAD side of the 13A one and not the supply side, then your diagram is fine.

 

[Taylortwocities]

Is this correct and legal?

Technically it is correct.
Legally you would need to notify this work to your local council and pay their fee as it is notifiable work under Building Regulations Part P.

Or get a registered spark to do it for you.

 

[Chri5]

Thank you both.
So is this the soloution as I understand it?:

Is this correct and legal?

Fine with the exception of using old wiring colours rather than new post 05 brown, blue, g/y

 

[mfarrow]

To comply with new regs you'll have to use new blue/brown wire colours or tape/sheath the ends of the old colour cable you use; oh and put a sticker on the consumer unit warning people of the use of two colours to BS 7671. Finally, don't forget to Part P with £200 to your council for the privilege.

Or... just don't bother

 

[derwentmax]

TWO HUNDRED QUID!!! TWO HUNDRED!!! Just to inspect?! I have a feeling the council would be surprised if I did request the inspection, if its going to cost that much!
Would it cost me that much for a sparky to do the work?

 

[mfarrow]

No it wouldn't cost that much to get a sparky.

As far as I see it, you've come on a forum requiring clarification of regulations, and you've drawn us a diagram.

You obviously are not a cowboy DIYer and are clearly looking to comply with BS 7671 as far as possible. How you comply with Part P is up to you.

But remember: if you don't register the work with the council and they find out somehow in the future that you carried it out since 2006, then you'll have to both pay the fee and you'll be instructed to bring the work up to standards if it's not already.

Yes I know what you're thinking; I'm getting hot under the collar just imagining receiving such a harsh punishment. Guy Fawkes and his mates had it easy!

 

[Gees]

No it wouldn't cost that much to get a sparky.



But remember: if you don't register the work with the council and they find out somehow in the future that you carried it out since 2006, then you'll have to both pay the fee and you'll be instructed to bring the work up to standards if it's not already.

Yes I know what you're thinking; I'm getting hot under the collar just imagining receiving such a harsh punishment. Guy Fawkes and his mates had it easy!

Is that why old colour twin and earth is so expensive

 

[Johnmelad502]

So long as the 3A FCU is attached to the LOAD side of the 13A one and not the supply side, then your diagram is fine.

Why?

I am sure you are correct, I just want to understand the reason.

 

[Taylortwocities]

If you connect it to the feed side then the first FCU is a spur, the second FCU is a spur off the first spur - and that ain't allowed.