What is the current in an electric motor operating with 85% efficiency and driving a 1.7-hp mechanical load with a supply voltage of 106 volts?
The current in the electric motor is 13.87 A.
Calculating Electric Motor Current
To find the current in the electric motor, we can use the formula: Power = Voltage x Current.
First, let's convert the mechanical load from horsepower to watts. Given 1 horsepower (hp) is equal to 736 watts (W), the mechanical load is:
1.7 hp x 736 W/hp = 1251.2 W.
Next, using the efficiency of the electric motor (85%), we can calculate the input power:
Input Power = Output Power / Efficiency
Output Power = 1251.2 W
Efficiency = 85%
Input Power = 1251.2 W / 0.85 = 1471.06 W.
Now, applying the formula Power = Voltage x Current, where the supply voltage is 106 volts:
1471.06 W = 106 V x Current
Rearranging the equation to find the current:
Current = Power / Voltage
Current = 1471.06 W / 106 V
Current = 13.87 A (approximately).
Therefore, the current in the electric motor is approximately 13.87 A.