Three-Phase Electrical Motors - Power Factor vs. Inductive Load

Calculate power factor, active power, reactive power, and apparent power for three-phase electric motors. Understand the relationship between power factor, inductive loads, and system efficiency.

Calculator

Inputs

Voltage (V) (V)

Current (A) (A)

Power Factor (cos φ)

√3 constant

Results

Active Power (P)-- W

Apparent Power (S)-- VA

Reactive Power (Q)-- VAR

Phase Angle (φ)-- °

Power (hp)	Speed (rpm)	Unloaded	1/4 Load	1/2 Load	3/4 Load	Full Load
0 - 5	1800	0.15 - 0.20	0.5 - 0.6	0.72	0.82	0.84
5 - 20	1800	0.15 - 0.20	0.5 - 0.6	0.72	0.74	0.84
20 - 100	1800	0.15 - 0.20	0.5 - 0.6	0.72	0.79	0.86
100 - 300	1800	0.15 - 0.20	0.5 - 0.6	0.72	0.81	0.88

Power Factor	1.0	0.9	0.8	0.7	0.6	0.5	0.4	0.3
Cross-Section Factor	1	1.2	1.6	2.04	2.8	4.0	6.3	11.1

Industry	Power Factor (%)
Brewery	75 - 80
Cement	75 - 80
Chemical	65 - 75
Electro-chemical	65 - 75
Foundry	75 - 80
Forging	70 - 80
Hospital	75 - 80
Manufacturing, machines	60 - 65
Manufacturing, paint	65 - 70
Metalworking	65 - 70
Mine, coal	65 - 80
Office	80 - 90
Oil pumping	40 - 60
Plastic production	75 - 80
Stamping	60 - 70
Steel works	65 - 80
Textiles	35 - 60