Grant wrote:
Christian McArdle wrote:

Christian, thanks very much for that explanation. The 1.44 ohms figure
has jogged my memory - last year an engineer came to fix my washing
machine and he carried out a test on the circuit. He told me that the
desired figure for a sucessful test was 1.44 ohms but the figure he got
from my circuit was 3-point-something (I have a note of it at home). he
told me not to worry because some old houses have values above 30 ohms!
So it looks like that circuit is already dangerous and I need a rewire.



Make sure the sockets are RCD protected. Although the circuit still
won't be
up to scratch and would still fail an inspection, this removes the main
potential danger.

Christian.



Lots of valuable advice so far - thanks everyone.

So, I will protect the sockets with an RCD until I get the rewire done.
Currently there is a 32A MCB for the sockets. Do I simply need to
replace this MCB with an appropriate RCD or is the RCD in addition to
the MCB? Do RCDs have the same kinds of ratings? In short, do I buy a
32A RCD and put it where the MCB currently is? Excuse my ignorance!

Cheers,
Grant
Its not quite as simple as that as MCBs are single pole on the live side
of the circuit whereas RCDs are double pole so work on both the live and
the neutral side. It may be possible, depending on your consumer unit
to replace the MCB with an RCBO - which is a combined RCD and MCB in one
unit that comes with the appropriate wire/teminals to connect in the
neutral as well.