# How do you calculate motor output?

Contents

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 find the output of a motor?

Calculations

1. I = V / R. where I – current, measured in amperes (A); …
2. Pin = I * V. where Pin – input power, measured in watts (W); …
3. Pout = τ * ω where Pout – output power, measured in watts (W); …
4. ω = rpm * 2π / 60. …
5. E = Pout / Pin. …
6. Pout = Pin * E. …
7. τ * ω = I * V * E.
8. τ * rpm * 2π / 60 = I * V * E.

## How is electric motor output measured?

Multiply the number of volts by the amperes to calculate the number of watts of the motor. For example, the number of watts of a power screwdriver with a rated voltage of 120 volts and 4 amperes is 480 watts (120 volts x 4.0 amps = 480 watts).

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## How do you calculate motor output speed?

Calculating Output Speed Using Pulley Diameters and Input Speed

1. RPM Output/RPM Input = Multiplication Factor. On a belt-driven fan the two primary speeds required are the RPM of the Motor and the RPM of the fan. …
2. Formula. RPM Input/RPM Output = Diameter Out/Diameter In.
3. Formula. …
4. RPM Out = 1,002.13.

## What is the formula for output power?

To calculate the power output, you should multiply the Load/Amperage by the Line Voltage.

## How do you calculate motor load capacity?

When calculating motor loads, you need to know how to convert a motor’s current rating (given in amps) to a VA rating. To do this, multiply the motor’s nameplate amperage by the supply voltage.

## How do you calculate motor current from kW?

Single Phase AC – kW to amps

For any single-phase AC circuit, Current, I = 1000 x kW / (Vac x P.F.) Therefore, amps can be calculated from AC – kW by dividing kW by the product of the RMS value of applied AC voltage and power factor and multiplying it by 1000.

## How do you calculate the output power of a DC motor?

Power. The power of a motor is the product of its speed and torque. The power output is greatest at about half way between the unloaded speed (maximum speed, no torque) and the stalled state (maximum torque, no speed). The output power in watts is about (torque) x (rpm) / 9.57.

## How is motor horsepower calculated?

Use this formula to estimate motor horsepower. Horsepower(hp)= Voltage x Amperage x % EFF x power factor x 1.73/746.

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

1-phase motor

1. In = rated demand (in amps)
2. Pn = nominal power (in kW)
3. U = voltage between phases for 3-phase motors and voltage between the terminals for single-phase motors (in volts). …
4. η = per-unit efficiency, i.e. output kW / input kW.
5. cos φ = power factor, i.e. kW input / kVA input.
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## How do you determine the output RPM of a gearbox motor?

Write down the ratio of the speed reducer; for example, 12:5. Calculate the reduction by dividing 12 by 5, which equals 2.4. The RPM of the assembly is the RPM motor divided by the reduction. In our example, it would be 5000 RPM/2.4 = 2083 RPM.

## How do you calculate power output watts?

In other words, watt=amp X volt. Sometimes you will see this formula written as W=A X V. For example, if the current is 3 amps (3A) and the voltage is 110V, you multiply 3 by 110, to get 330W (watts). The formula is P=3A X 110V = 330 W (with P standing for power).

## How do you calculate the power of a 3 phase motor?

Calculate three-phase motor power consumption by multiplying amps by volts by the square root of three (W = AV(sqrt 3). For example, if the motor is drawing 30 amps at 250 volts, you have 30 x 250 x sqrt 3 (about 1.73) = 12,975 watts).

## How do I calculate wattage?

The formula for calculating wattage is: W (joules per second) = V (joules per coulomb) x A (coulombs per second) where W is watts, V is volts, and A is amperes of current. In practical terms, wattage is the power produced or used per second. For example, a 60-watt light bulb uses 60 joules per second.