UPS Losses and Efficiencies

[joan271273]

1.- How can I estimate the losses and/or efficiencies of uniterruptible power supplies.
2.- Any good links on the web

 

[mpparent]

These values should be available from your UPS manufacturer, based on kVA, input filter or no, etc.

Mike

 

[joan271273]

Sure!!!!!!,but usually they are not forthcoming or really do not make sense.

 

[dpc]

One thing to look at is the input power requirement. The UPS will generally have an output rating and an input kVA or amperage rating.

If you are talking about larger commercial-grade UPS, the specifications should include this data, as well as efficiency.

 

[mpparent]

Not forthcoming?? I don't know if you're buying a UPS(static or rotary), but if they won't give you the info., I wouldn't give them your business. As for not making sense, I've not run across an equipment spec. that didn't.

Mike

 

[jbartos]

Suggestion: Visit

http://www.electricityforum.com/et/issue0102/i01_ups.htm

etc. for more info

 

[peebee]

The major UPS manufacturers all publish efficiency ratings for their UPS systems.

 

[joan271273]

The article by Bartos points out exactly what I am experiencing. The manufacturers data is published based on UPS loading factors above 50%. A lot of the configurations nowadays are in N+1 ,etc therefore having these units in 25-60% range. Manufacturers do not provide data at this range.

 

[mpparent]

As I read the article, and what you're pointing out about 25-60% operation, part of that can be controlled by knowing your equipment and designing to real world load data(I think we've all seen that typically, loads are 1/3 what they really are.) However, I believe I have seen the data you are inquiring about from my UPS vendor. I'm confused as to why you're having difficulty.

Mike