calculating KVA to Amps

[SIP6A]

When you do the calculations for KVA to Amps is the formula different for 3 phase Vs single phase?

 

[drcoelho]

single phase kVA = (V x A) / 1000

3 phase kVA = (V x A x 1.73) / 1000

 

[52 Ford]

single phase kVA = (V x A) / 1000

3 phase kVA = (V x A x 1.73) / 1000

I don't deal with 3 phase power enough.

I get that V*A=VA, but what's the 1.73 signify?

Sent using Morse code on - .- .--. .- - .- .-.. -.-

 

[SIP6A]

single phase kVA = (V x A) / 1000

3 phase kVA = (V x A x 1.73) / 1000

Thanks!!

That's what I was looking for.

Todd W

 

[SomeoneSomewhere]

It's due to trigonometry and the underlying maths. The square root of three is 1.732 something something something.

If you imagine three line-to-neutral loads, then the total power is 3x the power of a single load.

Line to line voltage is sqrt3 times higher than line to neutral, so multiplying by sqrt3 again gets you to the 3x power. Obviously, sqrt3 * sqrt3 = 3.

 

[52 Ford]

It's due to trigonometry and the underlying maths. The square root of three is 1.732 something something something.

If you imagine three line-to-neutral loads, then the total power is 3x the power of a single load.

Line to line voltage is sqrt3 times higher than line to neutral, so multiplying by sqrt3 again gets you to the 3x power. Obviously, sqrt3 * sqrt3 = 3.

Gotcha. Thank-you! Like I said, I don't deal with much 3 phase - especially not the math behind it. 99.95% of my electronics related math is split between 60Hz single phase (120 and 240V) and DC.

Frankly, for what I do, the only time I deal with VA is converting it to Volts and Amperes. Just the typical stuff. Sizing breakers and fuses and what-not.

Sent using Morse code on - .- .--. .- - .- .-.. -.-

 

[drcoelho]

I don't deal with 3 phase power enough.

I get that V*A=VA, but what's the 1.73 signify?

Sent using Morse code on - .- .--. .- - .- .-.. -.-

1.73 is approx the square root of 3, since you have 3 phases that is where it comes from