The message .com
from contains these words:

Yes, but if your existing CU already has RCD protection on the sockets
this is considered OK.

OK by the letter of the regs, but far from ideal. A 30mA on a socket is
better protection than a 100mA in a CU. It's also less likely to trip
and take out the freezer.

Ah, yes, sorry. I meant to add "considered by the regs, but in real life
I'd rather do...."

--
Skipweasel
Pay no attention to that man behind the curtain.