Q: How to determine electrical energy consumed by knowing the current of motor? I have an AC motor. It is running for 1 hours and I read the current every one minute and it reads 2A. 
So how to know how much the energy my motor already consumed? In this case, voltage is steady at 220V and not knowing the power factor(or make an assumptions that it is constant).

A: For single-phase AC, power is voltage X current X power factor. Power factor is a number between zero and one that indicates how closely the voltage and current waveforms coincide with each other. The power factor for full load may be marked on the motor. A typical motor will have a high power factor, perhaps 0.8 to 0.9 at full load, but a low power factor, perhaps less than 0.2 when it is lightly loaded. If the full-load current is marked on the motor, you can compare the measured current with the full-load current to estimate hoo heavily the motor is loaded. With no load, the motor current will likely be in the area of 1/3 of full-load current.

A: I am assuming that there is a steady load on the motor since the current is at 2A every time you check it. You mentioned the voltage is at 220V, so this gives you an operating power of 440W. (Power = Voltage x Current)
After the motor has been run for 1 hour, it consumes 440Wh of energy. (Energy = Power x Time)
