On 10/02/2019 23:41, Roger Hayter wrote:
ARW wrote:
On 10/02/2019 21:54, Roger Hayter wrote:
ARW wrote:
On 07/02/2019 23:27, Roger Hayter wrote:
snip
I've carefully avoided checking that the economy 7 circuit is wired as a
ring so far, but I suppose I could always use a smaller MCB.
A couple of options.
First of all find out if is a ring or not. Now is the time to find out!
If not a ring then swap the Wylex box for a new CU with 2 x 20A radial
circuits with RCBOs or a RCD main switch. Don't consider a 2 way garage
CU as you have 25mmm tails. You might just squeeze a 4way with main
switch CU in there.
If it is a ring then
a) swap the sockets for sockets with RCD built into them. Job done in
minutes.
b) swap the Wylex unit for a 32A double width RCBO in a suitable
enclosure (going to be tricky with 25mm tails)
or
c) follow the advice for the radial circuit and have 3 spare ways and
one 32A RCBO.
Thanks for the advice!
I've looked, and now wish I hadn't! The MCB is connected to a 10mm
cable (could just be 6mm, but I think it is 10). However, by the time
it gets to the sockets they are each wired with single 2.5mm cable.
There is presumably some sort of junction box somewhere, but what he
used that takes one 10mm and two 2.5mm wire I don't know. You'd think
it would be big enough to spot! I presume branched radials are frowned
upon, even with a suitable MCB. Fortunately I can scrap one of the
sockets, as it is unused, being intended for running a washing
machine/tumble dryer on Economy 7.
The branched radials are in your case called unfused spurs.
They are frowned upon by some but not by others (including me).
If it worries you then without a doubt the easiest and cheapest option
is to swap the MCB for a 20A MCB (you have to swap the back plate), fit
a RCD socket and blank off the other socket into a flex outlet plate or
into strip connector with a blank plate over it.
I am sure from your photos that this is the MCB you may need
https://www.screwfix.com/p/wylex-20a...g-in-mcb/80070
BTW If you do swap the MCB to a 20A the unfused spurs become branches:-)
--
Adam