Percentage usage of the total available source

To calculate demand factor

First, you calculate S (kVA)

Then You choose Q= 30%S.

Eg: S= 2000KVA

=> Q = 30%S= 600KVAr

Choose capacitor 50KVAr 10sets

100KVAr 2sets

____(60727/N.300).100% N being actual hrs. office was open inthe month

Say office was working 170 hours in that month> --DEMAND FACTOR=119 %!!

Friend--

If you are only looking at the average, then your total usage in kWh is divided by the number of hours of operation. This is your average demand in kW. Divide this by the power source output and multiply by 100 to convert to percent. This dimensionless number is the average percent of your power source's capacity you have used.

I am concerned about your use of an average in your post. Most commonly the connected load will vary during the day and during the month, depending on how many rooms have lights on, when machines are on or off, and if power is also being used for heating, cooling, or ventilation. The peak demand is often measured by averaging the demand for each 15-minute period of time throughout the month, and then remembering the highest value of these 15-minute periods. This can easily be twice or even three times the average demand for the month.

When you look at your power system, you have two choices. You can size the system to be capable of supplying the peak demand,, or you must have a way of disconnecting ("shedding") loads when you are reaching the system's peak supply capacity. You can also have a backup source of supply which is added to the main ("base") one when your consumption is exceeding the main source's capacity.

If your office is being used 9 hours each day, 5 days a week, and the typical month has 4.25 weeks, your hours of usage are 191.25. Therefore your average demand is 60727/191.25 = 317 kW, so your average percentage of load is 106%. If your office is being used 12 hours each day, 6 days a week, your hours are 306, your average demand is 198.4, and your average percentage is 66%. Just remember my concern--these are averages, not peaks.

--JMM