UPS Sizing

The Rack Size and IDF Size are both totally irrelvant to your question.

Today a single 47U rack can have from 0-20kW of load depending on the equipment installed.

So you need to develop your equipment list and we can help you out with a realistic UPS size.

If you want to limit the audience that sees the configuration you can Private Mail it to those you want to run it by. I'm quite happy to help you out with this.

Regards,
Sapper.

There is a company I know called M&H Power, they would be able to help you with your UPS, Batteries and sizing if you require, and I guess many more around the world ;o)

http://www.mhpower.com.au

Johnsly,

When sizing a UPS you have to consider the maximal load that you may have to feed from that UPS. When considering a rack, there is a total power that can be provided for it (based on the number & type of receptacles where equipment can be plugged in). In reality, even if you can use all provided receptacles, in most cases not all of them will be used at the same time. Therefore even if the total capacity for a rack is (let's say) 20 kW, depending on how many pieces of equipment are to be plugged in (and run) at the same time, the actual power requirement for that rack may be only 6-12 kW.

If that particular UPS has to serve several racks, the ratio between the actual power requirement (selected receptacles used at the same time) and the total power requirement (connected power-all receptacles used at their maximal capacity) may be as low as 0.4-0.5.

So you have to determinate that total actual power (kW) to select a UPS. It is advisable to add a 25% reserve when selecting the size.

Because most UPS have a limit of both real power (kW) and apparent power (kVA), make sure that both are within the limts.

The battery part of the UPS has to be selected based on the lenght of time you need to provide power from that UPS (you have a certain quantity of batteries if you have to provide the power for 15 minutes and roughly a double quantity of batteries if for 30 minutes, etc).