A kilowatthour (kWh) is the amount of energy a circuit working at a kilowatt of power transfers over the course of an hour. This unit is equal to 3,600,000 joules. The kilovoltampere (kVA) is the power rating of a circuit carrying 1,000 volts and an ampere or 1,000 amperes and a volt. A single kilovoltampere is equivalent to a kilowatt. To convert from kilowatthours to kilovoltamperes, you need to know only the time the circuit takes to transfer the energy.

Measure the length of time for which the circuit runs. For example, imagine a circuit that runs for 200 seconds.

Convert this value to hours by dividing by 3,600: 200 ÷ 3,600 = 0.0556 hours.

Divide the energy quantity, measured in kilowatthours, by this length of time. For example, if you are converting 0.25 kWh of energy: 0.25 ÷ 0.0556 = 4.496, or just under 4.5. This is the power rating in kVA.
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