Hey all,



Many moons ago i posted about a new CU and fitting



Well, did this myself which was easier than i thought, though time
consuming! Put in a MK 12way split-load which i hope will be sufficient.
I live in a trad 3 bed semi



Anyway, have now rewired the house (most of) and have three rings,
upstairs, downstairs (RCD) and kitchen, 2 light circuits, 1 new 45A
shower and 1 for immersion heater + 1 outdoor power circuit. Have yet to
add seperate non-RCD circuit for fridge/freezer



My question is should i put in a new ring for my computer room? It
basically hosts two pc's, monitor, printer, scanner, router, wireless
kit, speakers etc...all the normal stuff. Main PC is usually always on.
Is there any reason for putting it on a second circuit? Would i gain
anything? Ig i go down the new route, should it be a ring or radial and
if radial, what cable/fuse? Am currently putting extra sockets in this
room for said kit. Existing socket is currently on upstairs circuit (non
RCD)



Cheers



K

Is there any reason for putting it on a second circuit?

The only real advantage of a new ring is that you could wire it with high
integrity earthing, which is now required for rings expected to have large
amounts of Class I equipment likely to cause earth currents. You would
attach this to the non-RCD side of any consumer unit, although possibly with
its own RCBO if earth leakage current detection is required.

To wire a high integrity earthing circuit, you need sockets designed for it
(with 2 earth terminals). It is much easier to wire a high integrity circuit
as a ring, as the earthing must take two independent routes. With radials
and spurs, this is difficult and basically requires you to continue the ring
anyway with just the earth, so there is no advantage to a radial circuit at
all.

If large amounts of computer equipment are attached to a ring, it can push
the quiescent leakage up quite high, making the RCD too sensitive to any
other equipment and liable to trip, especially if the RCD is shared with
other circuits.

I wouldn't bother with a separate circuit myself. I would put the rings onto
RCBOs, rather than a shared RCD, though, so that all the quiescent currents
on all the circuits don't push the shared RCD into an oversensitive zone and
to give good discrimination between circuits.

Christian.