On 18/02/2013 21:21, John Rumm wrote:
On 18/02/2013 21:14, John Rumm wrote:

Some will argue that you can get even more load on it since a 13A BS1361
fuse

Sorry typo, BS1362 - 1361 are mains incomer fuses!




Incidentally. There has been a thought about ring mains that has
bothered me for some time.

in a perfect world, you have a continuous live loop and a continuous
neutral loop on a 32A MCB ring main, from teh CU to all the sockets and
then back to the CU.

What if you had a break in the cable between the CU and the last socket?
This converts the ring main to a radial circuit.

Lets assume the ring main is then loaded to its full capacity of 32A.

This would mean that *ALL* the current would be flowing along one route
between the CU and the first socket (assuming multiple appliances
plugged in a various points around the radial.

Can a single 2.5mm2 T&E really sustain a 32A continuous load?

Also as I understand it, you should only have a 20A mcb on a radial
circuit wired in 2.5mm T&E. if you complete the radial into a ring, then
the MCB can be changed to a 32A MCB.