Fred wrote:

On Wed, 19 Mar 2008 23:58:33 +0000, John Rumm
wrote:

You may want to consider a non RCD protected (or dedicated RCD/RCBO) for
the freezer. No point losing the contents when the PIR lamp gets damp!

Thanks. That's a good point. I thought all the regs. demanded RCD
protection now though?

The 17th edtn is not mandatory yet... you could also protect the circuit
cable such that it meets the requirements for a non RCD protected
circuit under the 17th edition.

However the simplest solution is a RCBO for that circuit. This does
include a RCD - but it is dedicated to that circuit and hence unaffected
by anything that may go wrong on other circuits.

I was going to get a 2-way garage CU but I think I now need a 3-way:
lights, sockets, and freezer socket.

I don't know much about RCBOs. I think they are the way to go: at
least they only switch off the faulty circuit rather than the whole
system when there is a fault, but OTOH don't they just switch the live
whereas a RCD's CU isolates both L&N when tripped?

No they switch both live and neutral - the neutral of the circuit has to
pass through them as well as the live (makes sense when you think how
they work). So they switch both. They normally hav a flying lead that
attaches them to the neutral bus bar in the CU. The circuit live and
neutral then attach to the RCBO.


--
Cheers,

John.

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