Previous in Forum: Install CT Before or After Breaker?   Next in Forum: Current Transformer
Close
Close
Close
7 comments
Rate Comments: Nested
Associate

Join Date: Jan 2011
Posts: 25

UPS-Battery Sizing

01/18/2011 3:40 AM

How to make Battery sizing for a 20kV, 240AC UPS ?

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#1

Re: UPS-Battery Sizing

01/18/2011 3:51 AM

Start by determining the size of the load and for how long the load is to be supported. That gives the amount of energy the battery is to contain. Divide the energy by the voltage to obtain the charge needed to be stored and allow a safety factor of, oh, say +20%.

"Robert is your mother's brother".

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Participant

Join Date: Jan 2011
Posts: 2
#2

Re: UPS-Battery Sizing

01/18/2011 5:28 AM

IEEE Std 1184-1994, IEEE Guide for the Selection and Sizing of Batteries for Uninterruptible Power

Systems (ANSI).

Register to Reply
Guru
United States - Member - Member Engineering Fields - Electrical Engineering - Electrical Construction

Join Date: Apr 2010
Location: Mid Western USA - The Corn Belt
Posts: 1439
Good Answers: 58
#3

Re: UPS-Battery Sizing

01/18/2011 8:21 AM

Try this web site: Google

Search: ups battery size guide

__________________
The first 5 days after a weekend are always the hardest................................
Register to Reply
Commentator

Join Date: Sep 2009
Posts: 99
#4
In reply to #3

Re: UPS-Battery Sizing

01/18/2011 9:37 AM

Be nice! ....

Register to Reply Score 1 for Off Topic
Active Contributor
India - Member - New Member

Join Date: Oct 2010
Location: India
Posts: 20
#5

Re: UPS-Battery Sizing

01/18/2011 9:49 AM

I think you are asking want to know about 20KVA UPS. I am giving a small description for Battery sizing calculation.. We have 2KVA inverter so i am writing about it so for 20 KVA calculate accordingly. 1. Output KVA = 2KVA 2. Output Power Factor = 0.8 3. Output KW = 20 x 0.8 = 1.6KW 4. Nominal DC voltage = 192 VDC 5. Minimum DC voltage = 168 VDC 6. Inverter Efficiency = 88% Idc(max.) = (Inverter kw x 1000)/(Min. DC x Inverter Efficiency) = (1.6 x 1000)/(168 x 0.88) = 10.82 Amp Let State of charge factor = 0.89 Idc(max.) = 108.23/0.89 = 12.15 Amp For 2 KVA UPS system with 60 minutes backup, Batteries could be selected as Ni-Cd, KPM 19P 1.2 V, 153 in numbers. Adjust ur 20KVA term accordingly. Experts please suggest if i m incorrect.

__________________
pstanwar9229
Register to Reply
Guru
Popular Science - Cosmology - New Member Technical Fields - Technical Writing - New Member Engineering Fields - Energy Engineering - New Member Engineering Fields - Electrical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Electromechanical Engineering - Old Member, New Association

Join Date: Apr 2008
Location: Lexington, KY
Posts: 1639
Good Answers: 73
#6

Re: UPS-Battery Sizing

01/18/2011 10:04 AM

Go to this web site www.apc.com where they have tools for sizing your backup system.

__________________
A great troubleshooting tip...."When you eliminate the impossible, whatever remains, however improbable, must be the truth." Sir Arthur Conan Doyle
Register to Reply
Guru

Join Date: Feb 2009
Location: Houston, USA
Posts: 946
Good Answers: 244
#7

Re: UPS-Battery Sizing

01/18/2011 6:52 PM

You didn't provide enough information. However, see this thread (especially the comment # 9) for detail:

http://cr4.globalspec.com/thread/38821/KVA-of-UPS

- MS

__________________
"All my technical advices in this forum must be consulted with and approved by a local registered professional engineer before implementation" - Mohammed Samad (Linkedin Profile: http://www.linkedin.com/in/msamad)
Register to Reply
Register to Reply 7 comments
Copy to Clipboard

Users who posted comments:

KJK/USA (1); kwoznia1 (1); msamad (1); NotUrOrdinaryJoe (1); Padmanabha (1); pstanwar9229 (1); PWSlack (1)

Previous in Forum: Install CT Before or After Breaker?   Next in Forum: Current Transformer

Advertisement