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.

Nigel Mercier ® wrote:


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?


Fewer chances of spikes, and brownouts. Plus this one should be on a
separate 100mA RCD (or none at all if you can't fit one in), as a
nuisance trip could lose you a weeks work!

If a nuisance trip costs more than 15mins work, then your back up and
auto save strategy is seriously flawed :-)
If the work is particularly valuable then I'd have chached write turned
off and a linked UPS with auto PC shutdown anyway.

Did I mention I have 3 current backups of my data :-) :-)

Lee
--
To reply use lee.blaver and NTL world com

Owain wrote:
"John Rumm" wrote
You might want to consider wiring a few sockets in a short radial
circuit to power all of the computer kit - but then wiring back to
the output of a decent UPS. The UPS being fed from the existing
ring. Then label all the sockets that are UPS protected so that
SWMBO does not go plugging a vacuum cleaner into them!

And so that it is obvious that those sockets may still be energised
even when the main switch is Off.

I'm contemplating this for my office. Answerphone, phone system and main
computer would then still be online during outages. As all the sockets are
white I thought about using different coloured ones for the 'safe' ones,
should be obvious enough then.

--
James...
http://www.jameshart.co.uk/

"James Hart" wrote in message
...
Owain wrote:
"John Rumm" wrote
You might want to consider wiring a few sockets in a short radial
circuit to power all of the computer kit - but then wiring back to
the output of a decent UPS. The UPS being fed from the existing
ring. Then label all the sockets that are UPS protected so that
SWMBO does not go plugging a vacuum cleaner into them!

And so that it is obvious that those sockets may still be energised
even when the main switch is Off.

I'm contemplating this for my office. Answerphone, phone system and main
computer would then still be online during outages. As all the sockets are
white I thought about using different coloured ones for the 'safe' ones,
should be obvious enough then.

--
James...
http://www.jameshart.co.uk/



Fit different sockets and use adapter tails. There are types with the earth
pin turned 90 deg, or with a T-shaped earth pin specifically for that
purpose.

Alternatively use IEC distribution blocks - those being the so-called
'kettle' lead used to power your PC etc. Then they are clearly very
different.


--
Woody

"Nigel Mercier ®" wrote in message
...
In uk.d-i-y, harrogate wrote:

Alternatively use IEC distribution blocks ...

Has anyone ever seen a standard 86mm single or double plate with
multiple IEC sockets? Obviously it would need a fuse, but I think this
would be so handy.


--
Nigel Mercier

Please remove NOSPAM from my return address


Farnell do a Rendar (their own brand) 6-way rated 10A, fused (and switched?)
and (if you want) with spike protection for less than the price of a 4-way
13A spike protected in the sheds.


--
Woody