Motor Efficiency and Power Factor Formulas

Опубликовано: 26 Октябрь 2024
на канале: AAA Mechanical Inc.

164

Efficiency and/or Power Factor are not known Formulas:
This is important because you can’t just use Watts = E X I out of ohms law then divide by 746 Watts to figure out horsepower and expect accurate results. Motors are not 100% efficient.

Existing Motor Information:
Single Phase Voltage is 230 Volts.
Full Load Amps 20.72.
Service Factor is 1.15.
Horsepower 5
Power Factor is .91
Percent Efficiency .86

Single Phase Motor Eff% = (HP x 746 Watts)/(PF x E x I)

Step 1: Single Phase Motor Eff% Unkown = (5 HP x 746 Watts)/(.91 x 230 x 20.72)

Step 2: Single Phase Motor Eff% Unknown = 3,730/4,336.696

Step 3: Single Phase Motor Eff% Unknown = .86 or 86% Efficiency

Single Phase Motor PF Unkown∶ PF= (HP x 746 Watts)/(Eff% x E x I)

Step 1: Single Phase Motor PF Unkown = (5 HP x 746 Watts)/(.86 x 230 x 20.72)

Step 2: Single Phase Motor PF Unknown = 3,730/4,098.416

Step 3: Single Phase Motor PF Unknown = .91 or 91% for a Power Factor

Single Phase Motor PF and Eff% Unkown∶ Combination Factor= (HP x 746 Watts)/( E x I)

Step 1: Combination Factor for %Eff and PF = (5 HP x 746 Watts)/(230 x 20.72)

Step 2: Combination Factor for %Eff and PF = 3,730/4,765.6

Step 3: Combination Factor for %Eff and PF = 0.782692

Step 4: .91 Power Factor x .86% Eff= 0.7826 which basically= Combination Factor Above