I have a 3 phase switching power supply that I am trying to calculate the maximum input power.
It is hooked up to a 3-phase, 277/480 VAC power source.
The sticker on the power supply says:
"INPUT : AC INPUT: 440V 3~; 3W+PE 10A 50/60Hz"
"OUTPUT := MAX OUTPUT POWER : 4920W"
So I know since this is a switching power supply, I would expect the input power to be higher than the output, but maybe just by 10% or so.
Going off the sticker values, and according to some old notes I had, the 3-phase power would be calculated like this:
S = sqrt(3) * Vll * Il * cos(theta)
Where Vll is the line-to-line voltage (440V)
Il is the "Current in one line". Not sure if this should be 10, or 10/3?
theta is the power factor. I'll assume 1.0 for now.
This gives me 7621 V-A if I use 10A, or 2540 V-A if I use 10A/3. Neither of these seem right.