What is the efficiency of a 10 hp DC motor that draws 31 amps at 300 volts?

To determine the efficiency of the 10 hp DC motor, it's essential to calculate both its input and output power.

First, we convert the horsepower to watts since electrical power is measured in watts. 1 horsepower is equivalent to approximately 746 watts. Therefore, a 10 hp motor has an output power of:

10 hp * 746 W/hp = 7460 watts.

Next, we need to calculate the input power. The input power can be determined using the formula:

Input Power (P_in) = Voltage (V) × Current (I).

Here, the voltage is 300 volts, and the current drawn is 31 amps. Thus, the input power is:

P_in = 300 V × 31 A = 9300 watts.

Now, we can calculate the efficiency using the formula:

Efficiency (%) = (Output Power / Input Power) × 100.

Plugging in the values we calculated:

Efficiency = (7460 W / 9300 W) × 100 = 80%.

This shows that the motor operates at an efficiency of 80%, which means that 80% of the electrical power is effectively converted into mechanical power, while the remaining 20% is lost primarily to heat and other