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Member

Join Date: Aug 2006
Posts: 9

11/03/2006 9:44 AM

I have about 24 kilowatts of connected load in my residential house. What will be the maximum demand for above loads. How I can calculate it my self, so that I can make application for approval of power from electricity board.

Can send me mail directly at shashi_39@dataone.in

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Guru

Join Date: Sep 2006
Location: CHINA
Posts: 2958
#1

### Re: Electrical Load demand calculations

11/03/2006 8:45 PM

At first, you have to make clear what kind of load it is, so that we can have relevant coeficient to mulitiply.

Member

Join Date: Aug 2006
Posts: 9
#3

### Re: Electrical Load demand calculations

11/04/2006 9:03 AM

Thanks for your reply. It has mixed type of loads, mainly single phase lights, fans, air conditioners, water storage geysers. One no. 3 HP 3 phase 440 volts pump motor. Please also advice me how to distribute loads so that I can gain maximum advantage with minimum installation and recurring cost.

Anonymous Poster
#2

### Re: Electrical Load demand calculations

11/03/2006 10:56 PM

you need to mention following data also to be able to do load calculation:

1) how many electric motors are there which you are using in your house, what are their types (3phase , 1 phase etc).

2)are you using starters in your house for above motors, are they likely to be started together ?

3) will these motors run all at the same time.

5) Is it likely that all the connected load will be switched on together.

6) also, considering Future expansion is very important, you can take 10 to 30% extra for future expansoion depending on expansion that is possible.

Member

Join Date: Aug 2006
Posts: 9
#4

### Re: Electrical Load demand calculations

11/04/2006 9:14 AM

Thanks for your reply. Yes I ll use 1 no. 3 HP 3 phase 440 Volts motor for water pump, and may be single phase motors in air condition machine etc.

For these motors I ll use starters as recommended.

I ll not use all the loads together normally, but may be (not sure) some time i ll use during any party at home. But please advice as per normal and regular uses.

At present there is no scope of any expansion of area of my house, so if it is necessary to consider expansion any time, I think 10% will be enough for me.

Active Contributor

Join Date: Sep 2006
Posts: 10
#5

### Re: Electrical Load demand calculations

11/06/2006 10:52 AM

My point is:

1 - when you sign agreement if it is possible try to sign for one year. But most of them they force you to sign for 5 years.

2- If you get for one year agreement sign for a high (may be 18KVA demand, you will get +/- 15% range)

3- Track your KVA demand in a year (from your bill) and determine what is the maximum KVA was in a year, so when you sign agreement in the next term that will be your maximum KVA.

4- some people they use 65% coincident demand factor (24 x .65) = 15.6KVA but it has some risk.

I hope this helps if you need further information, put it in this blog

Power-User

Join Date: Sep 2009
Location: Houston, TX
Posts: 118
#6

### Re: Electrical Load demand calculations

09/05/2009 3:36 PM

In determining power requirements a "Load Analysis" must be prepared. Yes you can do it yourself if you know how with simple math. The idea behind it is the fact that if you totaled the connected load in your residedance or onsite power and used that for sizing your power source, you would need a transformer or generator somewhere near the size of your house! I deal with onsite power and sizeing a generator is a critical path! We have to know this information prior to buying generators/engines and it has to be right. Now back to your question: Power usage is calculated on a duty factor, e.g., how much load in kw and how many parts of a 24 hour period it is used. For example, suppose you have electric heating that is say, 10 kw. Your heating unit kicks on about 30% of the time in a 24 hour period. You then have a usage factor of 0.3 time 10 kw equal 3 kw. These usage factors imminated from recording equipment, documented and handed down in many industires. These factors are determined by application, however, some are the same for the example above. Common sense tells us that the example I used was based on a warmer climate that northern states/countries.

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