Ring main circuit

[Stefanplant]

When I wire a ring main from the consumer unit, does the ring eventually come back to the same connection in the fuse box or a unused one?

Also if I wire a socket from the consumer unit with no return, can I run another socket from this first socket as a spur.

Thanks,

Stefan.

 

[Rusty2]

Hi Stefan - yes in order to make a ring main a proper ring you must return the cables back to the same MCB or fuse.

If running out from the unit and not returning this is called a radial line and you can add sockets on after the first, but there is a limit to the lenght you can go with this. Also, make sure you have the right size fuse or MCB if only a radial.

REMEMBER - if connetcing new circuits then you ought to be Part P registered these days, so are you sure you want to do this!

Rusty2

 

[Lectrician]

A little misleading.... No limit to length, you must however consider the volt drop. You can only serve certain sizes of floor area per circuit type.

Ring Circuit (NOT RING MAIN!!)
- 100m/sq area
- 32amp MCB
- 2.5mm/sq cable min.

32amp Radial Circuit (NOT LINE!!)
- 75m/sq area(used to be 50)
- 32amp MCB
- 4mm/sq cable min.

20amp Radial Circuit
- 50m/sq area(used to be 20)
- 20amp MCB(used to be 16amp)
- 2.5mm/sq cable min.

 

[ban-all-sheds]

REMEMBER - if connetcing new circuits then you ought to be Part P registered these days

Why do you say that?