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rajkumarabirami
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Join Date: Jan 2011
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UPS-Battery Sizing

01/18/2011 3:40 AM

How to make Battery sizing for a 20kV, 240AC UPS ?
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PWSlack
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#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%.

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Padmanabha
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#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).
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KJK/USA
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#3

Re: UPS-Battery Sizing

01/18/2011 8:21 AM

Try this web site: Google

Search: ups battery size guide

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kwoznia1
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#4
In reply to #3

Re: UPS-Battery Sizing

01/18/2011 9:37 AM

Be nice! ....
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pstanwar9229
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#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.

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NotUrOrdinaryJoe
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#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.

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msamad
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Location: Houston, USA
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#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

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