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why inverter rating in KVA?

Thread Starter: pravin.pande   Started: 7/17/2010 1:44 PM   Replies: 11

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  7/17/2010, 1:44 PM
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why inverter rating in KVA?
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  7/17/2010, 2:58 PM
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Hello pande;
Could you give us an example of inverter ratings in kVA?
Most inverter ratings I have used were in kW or HP.
Hope this helps,
Daniel Chartier
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  7/18/2010, 7:44 AM
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pravin.pande wrote:
why inverter rating in KVA?


Hello Pravin,
Your this question is related to drive or with power source? If it is related to drive then inverters are rated in Kw. If this is related to power source then the rating of inverter is in KVA. Generally in case of power source, the connected load equipements rating is provided in watts but their actual current varies as those equippements power factor are differents. e.g. tube lights p.f. 0.4, CFLs p.f. 0.6 ,fans p.f. 0.8, T.V. p.f. 0.6 set etc. Hence actual total load current needs to be calculated & accordingly inverter is to be selected.If it is not calculated then inverter rating may be undersized & this may lead to overloading of inverter. e.g. 700 VA inverter at 230 Volt is supposed to supply 3 A load. (500 W max load you can connect on 700 VA & not 600 or 650 watt
Hope this helps to solve your query.
DEEP.



=== Edited by DEEPSTR2010 @ 7/18/2010 7:46 AM [GMT ] ===



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  5/24/2014, 8:23 PM
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PISCEAN 2010 wrote:
pravin.pande wrote:
why inverter rating in KVA?


Hello Pravin,
Your this question is related to drive or with power source? If it is related to drive then inverters are rated in Kw. If this is related to power source then the rating of inverter is in KVA. Generally in case of power source, the connected load equipements rating is provided in watts but their actual current varies as those equippements power factor are differents. e.g. tube lights p.f. 0.4, CFLs p.f. 0.6 ,fans p.f. 0.8, T.V. p.f. 0.6 set etc. Hence actual total load current needs to be calculated & accordingly inverter is to be selected.If it is not calculated then inverter rating may be undersized & this may lead to overloading of inverter. e.g. 700 VA inverter at 230 Volt is supposed to supply 3 A load. (500 W max load you can connect on 700 VA & not 600 or 650 watt
Hope this helps to solve your query.
DEEP.

dear piscean   what  happens  if  i connect  2 batteries of  12 volt in parallel  instead of  1 battery of 12 volt  to inverter   .....will it work  or  it will damage  inverter   as  current will become double
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  5/24/2014, 10:00 PM
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maximus09 wrote:

dear piscean   what  happens  if  i connect  2 batteries of  12 volt in parallel  instead of  1 battery of 12 volt  to inverter   .....will it work  or  it will damage  inverter   as  current will become double


You must not do wrong voltage or connection! blush

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  5/25/2014, 1:14 AM
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Check for battery discharge current too. thinkthink
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  5/25/2014, 3:15 AM
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maximus09 wrote:

dear piscean   what  happens  if  i connect  2 batteries of  12 volt in parallel  instead of  1 battery of 12 volt  to inverter   .....will it work  or  it will damage  inverter   as  current will become double


In addition to IBN-Service 's answer

IBN-Service wrote:
You must not do wrong voltage or connection! blush


I want to add that, by connecting batteries in parallel, your Current will not be double instead your Current Capacity will be double. I hope you got what i meanblush

Wait.. which type of inverters we are talking about? Inverters connected to Batteries to feed during power failures??think I think original question was related to Inverter drives, used for Protection and Speed control of motor

BTW, most of the drive manufacturer giving rating in KW or hp but ABB giving rating in KVA for their inverter module. Reason may be as explained above, PF depends upon load. Just like transformer is rated in KVA/MVA while motors are in KW/MW

Regards,
Devesh Vithani

I dont Like people driving Fast, thats the reason I overtake them ;)
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  5/25/2014, 9:14 AM
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Vithani wrote:


I want to add that, by connecting batteries in parallel, your Current will not be double instead your Current Capacity will be double. I hope you got what i meanblush

Wait.. which type of inverters we are talking about?
...


He he is talking about "Fuse distroyer" equipment, not a Inverter...  sleep

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  5/25/2014, 10:19 AM
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pravin.pande wrote:
why inverter rating in KVA?


All the Switching Devices are rated for a certain Voltage and Current, so the real rating would always be in kVA ( Derived by by multiplying the two ). The kW will vary depending on the Power Factor ... so if there is a kW Rating specified, it is based on a certain assumed worst case power factor.

In any case maximum Current / voltage cannot be exceeded .. consequently maximum kVA is fixed.

maximus09 wrote:

what  happens  if  i connect  2 batteries of  12 volt in parallel  instead of  1 battery of 12 volt  to inverter   .....will it work  or  it will damage  inverter   as  current will become double


I think, your question is about Household Invertors...

You will need to check the maximum Current Rating of your invertor and also the Battery Charger.
2 Batteries in Parallel will usually double your backup time in case of the power failure. However you need to check if your Charger is capable of charging the two batteries in parallel.

At the same time, you should not use one 12V battery in place of 2 in parallel if the Invertor is designed for operation with 2 batteries in parallel. It may get overloaded and damaged.

Hope this helps

Cheers

Navnag



=== Edited by Navnag @ 5/25/2014 10:20 AM [GMT ] ===



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  5/25/2014, 5:45 PM
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KVA means active and reactive power components , the reactive power is important in power saving mode
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