RE: Re: UPS for node 0

["Nigel Giddings" <nigel.giddings@xxxxxxxxxxxxxx>]

In my Node 0 I use 2 Compaq 3Kw UPSs, Each UPS has 9 connectors on the
rear. Each group of 3 connectors has a trip and can be automatically
shutdown at different times if a power fail occurs allowing you to shed
non-essential load to increase up time on batteries and allow controlled
shutdown of PCs / Servers. Therefore each device has a separate
connection between the back of the UPS and the device. The devices are
spread to reduce the impact of a UPS or Breaker failure.

I intend to have a 10Kw genny for the house with a self start so the UPS
should only need to support the load for 5 minutes maximum. However,
with Genny / UPS systems you have to be sure the UPS accepts the Genny
o/p as good mains (frequency, voltage etc.) At the moment the UPSs give
about 30 minutes autonomy.

The UPS connect to the servers with Dual PSUs so even if a UPS (or
server PSU)fails it doesn't knock off the Servers, they are running
Homeseer, MS SBS and IIS / Apache. Of course the router/ADSL is on only
one UPS so I would lose connectivity to the house. I will need to look
at running via a battery backed DC Supply.

I think these UPSs are great and having only paid about =A3100 each on
E-Bay I think they are Fantastic...

http://photos.corbenic.co.uk/photos/photo_181.html

HTH Nigel

www.creatingdreamhomes.co.uk




-----Original Message-----
From: Patrick Lidstone [mailto:patrick@xxxxxxx]=20
Sent: 07 April 2004 22:15
To: ukha_d@xxxxxxx
Subject: [ukha_d] Re: UPS for node 0

--- In ukha_d@xxxxxxx, "Dean Barrett" <dean@r...> wrote:
> Did this for a guy the other day.
>=20
> We wired his study in a 4mm radial rather than ring.
>=20
> Went via a pair of 45a Flex outlets side by side in a deep bar box.=20
Linked
> together internally.
>=20
> When he is ready to install UPS, removes links - put input into one=20
flex
> outlet and output on other...
>=20
> Other alternative is to have a small sub board fed from your mains=20
with a
> dedicated MCB again cutting the sub boards feed with UPS.
>=20

I'm not sure I'd do it this way - if you lose your UPS for any=20
reason, the whole of Node 0 goes down. Bear in mind that if your=20
outlets are not individually fused, a fault that develops in any of=20
the protected equipment (such as a switch mode power supply failing=20
dramatically) will take out the whole of the protected side of your=20
supply instantaneously, completely defeating the objective of having=20
a UPS. A common approach in many comms rooms to mitigate this=20
eventuality is to have one UPS per rack, and feed one piece of=20
equipment per fused outlet on the UPS.

Patrick



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