Originally Posted by robk

"In a three phase system, power P = U * I * sqrt(3) * cos(phi), where U is the voltage (rms), I the amperage (rms), sqrt(3) is the square root of three, and cos(phi) is cosine of phi, where phi is the angle between U and I. For pure resistive load, phi is zero (i.e. cos(phi) = 1), making the calculation pretty easy in this case. For inductive or capacitive loads such as motors or flourescent lights, phi moves to different values and must be estimated, measured, or calculated.

Find the Amperage of an 7200w inductive (i.e. motors, pumps, fluorescents etc.) load on a 415 Volt,
3 phase

branch circuit.

I = 7200 / (415 x 1.732) = 10.01 Amps per phase."

solve for 240V

I = 7200 / (240 x 1.732) = 17.32 amps per phase


-From wiki answers


Lower voltage creates higher amp draw
ps you have 3 phase to the motor