Jeff Layman wrote:
Fortunately not mine!

A friend just told me "I have just replaced a single electric socket in
our lounge with a switched double. In order to stop the supply, I had to
switch off two trip switches at the same time." That didn't sound right,
or safe.

DIYWiki notes: at (http://wiki.diyfaq.org.uk/index.php/Ring_circuit):
"The ring circuit cable starts at the consumer unit (fusebox]), visits
each socket in turn, and then returns to the consumer unit. The 2 cable
ends at the CU are connected together in all modern rings, and supplied
by one fuse or MCB."

That confirms there should be one MCB, but I note the use of "...in all
modern rings...". Does that mean there might have been two fuses or MCBs
in early rings? I think his house was built around 1980.

Our house (as in the house I grew up in, back in the 1950s) had a very
early ring circuit as it was built in 1949 or thereabouts. It
definitely had fuses at each end of the ring. Whether that was as it
should have been or just how the electrician (my father I think)
thought it should be I don't know.

--
Chris Green
·