Spur's?

[securespark]

if the customer changes the parameters when you have left and a fire starts.

Why should this occur?

 

[pdcelec]

When they plug in high current using equipment (which was not mentioned during installation) and the current summing junction in the original socket gets hot, insulation melts, the rest being evident

 

[ban-all-sheds]

30A JB

30-32A protective device.

Fire?

Hmmmmm.

 

[pdcelec]

20A cable X 4 each producing heat.
20A spurs X 2 thus Iz = 40A

 

[ban-all-sheds]

if possible , could someone give me a definitive answer to my original post?

It's not ideal, but you can do this if you want.

You might like to consider extending the ring to the new socket, rather than spurring it

Or doing it like this:

[code:1]----[SKT]----
|
|
[FCU]
|
|
[SKT]
|
|
[FCU]
|
|
(lights)[/code:1]

The real problem is not the load - if it were the other way round, i.e. you already had a spurred socket, and you wanted to add the lighting FCU, I don't think people would be warning that the extra 3A would be the death of you.

The real, practical problem with your plan is getting 4 conductors into each socket terminal, and ensuring that they are all tightly gripped - you do not want to end up with a situation where 3 of them have got tightly jammed together and are not being forced onto the 4th....

 

[pdcelec]

That setup would be the way I would go since no more than 13A can get past the first FCU.

 

[nabby68]

ok everyone thanks for all the advice, i think it may be time to put this post to rest !

thanks ban for the diagram and the suggestion of extending the ring,. me thinks this may be the better option but might incur more structural work, so i might also consider the fcu in between the spur and the spurred from socket.

once again thanks to everyone who replied.

 

[ban-all-sheds]

20A spurs X 2 thus Iz = 40A

In = 30 or 32A..

 

[pdcelec]

Ib = ?A. Only the designer will know this one

 

[Spark123]

Ib=<32A

 

[Jaymack]

This appears to imply one spur only, from a socket on a final ring circuit in this case: -

From BS1363-2, clause 11.5:
--------------------------------------------------------------------------------
Line and neutral terminals in fixed socket-outlets shall permit the connection without special preparation of one, two or three 2.5 sq mm solid or stranded or one or two 4 sq mm stranded conductors.

It ain't in the knowing, it's knowing where to look.