By taking the voltage and multiplying it by the associated current, the power can be determined. A watt (W) is a unit of power defined as one Joule per second. For a DC source the calculation is simply the voltage times the current: W = V x A.

## How do you calculate the mechanical power of a motor?

Mechanical power is typically defined as kilowatts or horsepower, with one W equaling 1 Joule/sec or 1 Nm/sec. Figure 9: Mechanical power measurements in watts are defined as **two times Pi times the rotating speed (rpm) divided by 60 times the torque (Newton-Meter)**. Horsepower is the work done per unit of time.

## What is the power output of an electric motor?

Most electric motors are designed to run at **50% to 100% of rated load**. Maximum efficiency is usually near 75% of rated load. Thus, a 10-horsepower (hp) motor has an acceptable load range of 5 to 10 hp; peak efficiency is at 7.5 hp. A motor’s efficiency tends to decrease dramatically below about 50% load.

## What is the efficiency formula?

Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula **r=P/C**, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.

## What is the output power?

In physics, power is the amount of energy transferred or converted per unit time. … The output power of a motor is **the product of the torque that the motor generates and the angular velocity of its output shaft**.

## What is the output of a motor?

In an electric motor, the mechanical power is defined as **the speed times the torque**. Mechanical power is typically defined as kilowatts (kW) or horsepower (hp) with one watt equaling one joule per second or one Newton-Meter per second. Horsepower is the work done per unit of time.

## Do electric motors have horsepower?

Electric Motors

An electric motor’s output is measured in kilowatts. Companies that build electric cars continue to talk about horsepower because consumers are still more familiar with that type of unit. The equation is as simple as **hp = kW x 1.369**, so a 100-kW motor produces 136 horsepower.