Hi,

My kitchen is currently empty and I'm re-wiring it before I have a new
one fitted. I have added in a few bits of extra cabling (spurs for
cooker hood etc.) and replaced some sections with longer pieces in
order to allow me to move sockets about. I've been using 2.5mm^2
cabling as this is what was recommended in the shop, I believe this
this fairly standard.

All the sockets are on a ring and they are on a 32A MCB in the consumer
unit. However, I have noticed on the packet for the cable that it says
'maximum load 27A' (the cable is made by Pirelli and is from B+Q).

Does this mean that I need to change the MCB for one of 27A or less? Or
would that be the maximum load on a radial rather than a ring?

Thanks,

Ian.

In article . com,
"Ian Atkinson" writes:
Hi,

My kitchen is currently empty and I'm re-wiring it before I have a new
one fitted. I have added in a few bits of extra cabling (spurs for
cooker hood etc.) and replaced some sections with longer pieces in
order to allow me to move sockets about. I've been using 2.5mm^2
cabling as this is what was recommended in the shop, I believe this
this fairly standard.

All the sockets are on a ring and they are on a 32A MCB in the consumer
unit. However, I have noticed on the packet for the cable that it says
'maximum load 27A' (the cable is made by Pirelli and is from B+Q).

Does this mean that I need to change the MCB for one of 27A or less? Or
would that be the maximum load on a radial rather than a ring?

It's the max radial load, although the actual maximum is
really a complex function of ambient temperature, and how
the cable is installed.

--
Andrew Gabriel

On 1 Oct 2006 05:00:10 -0700 someone who may be "Ian Atkinson"
wrote this:-

All the sockets are on a ring and they are on a 32A MCB in the consumer
unit. However, I have noticed on the packet for the cable that it says
'maximum load 27A' (the cable is made by Pirelli and is from B+Q).

Does this mean that I need to change the MCB for one of 27A or less?

No, as the sockets are on a ring there are two cables to carry the
current.

Or would that be the maximum load on a radial rather than a ring?

It is a figure the shop or manufacturer have put on the cable to
give people some sort of idea. However, the maximum load it can
safely carry depends on things like how and where it is installed,
the temperature of the surroundings and the characteristics of the
protective device. A piece of cable embedded in insulation is
allowed to carry less current than the same cable embedded in
plaster.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Does this mean that I need to change the MCB for one of 27A or less? Or
would that be the maximum load on a radial rather than a ring?

No. To be suitable for a 32A ring circuit, the cable must be rated at 20A or
above. 2.5mm complies, unless several derating factors apply, usually
involving burying in insulation.

Christian.

Christian McArdle wrote:
Does this mean that I need to change the MCB for one of 27A or less? Or
would that be the maximum load on a radial rather than a ring?

No. To be suitable for a 32A ring circuit, the cable must be rated at 20A or
above. 2.5mm complies, unless several derating factors apply, usually
involving burying in insulation.

Christian.

Thanks all for you help, I can plaster it in now without worrying about
it!

Ian.