I am trying to determine the most accurate way to calculate the existing load on an emergency generator from the amperage reading, while the generator is running under load. I will use a generator with the following nameplate information as an example : 208 V, 500 kVa, 400 kW, 0.8 Power Factor, 1388 Amps.
If my generator reads 600 Amps while running with the load, I know I take 600 amps x 208 v x 1.732 (3 phase power) which gives me 216,153 Watts. I can divide by 1000 to give me approximately 216 kW while under load. My question is do I take that number and divide by 400 kW, or do I divide by 500 kVa to get the load?
Could I also simply take that 600 Amp reading and divide by the 1388 Amp from the generator nameplate?
These 3 ways would give me 1 of 2 answers, and I do not know which one is correct. Any help is very much appreciated.