Formula for KW to amps

[deharoj]

What is the formula for taking KW to amps? The formulas that I have ask me for a power factor number but I don't know how to get my power factor number. The question is What size breaker do I need for 20kw at 3phase 208v?

 

[ron]

The power factor will depend on the load.
To convert from watts to amps, you need to know the power factor and voltage (and whether it is single phase or three phase).
A heater or incandescent light bulb will have a power factor of 1.

 

[bphgravity]

20,000 W / 208 V / 1.732 = 56 A. That's going to be pretty close even considering pF.