How many watts will you get from 10 KVA?

Answer 1

In AC service, it's written that way because 1-volt x 1-Amp is generally not 1-watt.

The problem arises because inductive or capacitive loads on the line have the effect

of introducing a 'phase angle' ... the phenomenon where the AC voltage and current

don't both wiggle at exactly the same time.

"Watts" measure the useful power drawn from the line, power that can heat a

toaster or turn a strong motor. If the voltage and current don't exactly line up,

then the amount of useful power is reduced. In the extreme, if voltage and

current are offset by 90 degrees of the cycle, then the line delivers no useful

power at all.

The amount by which the voltage and current on the line are separated in time

is called the "power factor". It's just the cosine of the phase angle between

voltage and current, and it's always equal to '1' or less.

The "watts" of real, useful power delivered on the line is (voltage) x (current) x (power factor).

So the kilowatts of real power is equal to (KVA) x (power factor).

We have no way of knowing what the power factor is on the line that the question

is referring to.

Since most of the household load consists of inductive devices ... things with

coils in them, like motors and toasters ... the power factor can be improved by

hanging capacitors across the line to compensate. Look carefully up the utility

poles in your neighborhood while you're walking (not driving), and eventually

you'll spot a group of rectangular cans mounted on the pole, probably near a

transformer. Those are the line capacitors that compensate for the inductive

load, increase the power factor, and help squeeze more watts out of every KVA.

Answer 2

Assuming a power factor of 1 (unity), you will get 10,000 watts from a 10 kVA (kilovolt-ampere) generator. This is because the power in watts is equal to the apparent power in volt-amperes when the power factor is 1.