# Frequent question: How can you tell the size of an electric motor?

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## How do I know what size electric motor I have?

Divide the motor speed by the required speed and round down to get a starting gear ratio. Then divide the required torque by the gear ratio to find the newly required torque. This will help you narrow the choices down to a few select motors.

## How do you read a motor size?

A motor size is based on the stator size (diameter and height).. For example if a motor is sized as 2207, it means that the stator is 22mm in width and has 07mm in stator height.

## How do you identify motor power?

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.

## What three factors are used to determine the size of a motor?

In order to determine the performance you’ll need from the motor, there are three factors to calculate; Moment of Inertia, Torque and Speed.

## What is sizing of motor?

Motor Sizing Motor sizing refers to the process of picking the correct motor for a given load. … If a motor is too small for an application it may not have sufficient torque to start the load and run it up to the correct speed.

## How do I know what motor is right for me?

Consider an application’s purpose and which current it uses to select the appropriate type of motor. An application’s specifications such as voltage, current, torque, and velocity will determine which motor is most appropriate so be sure to pay attention to its requirements.

## What do the numbers mean on RC electric motors?

The number of turns indicates how much wire is wrapped inside the motor. A higher turn number means more wire and thus more resistance, resulting in a slower motor. So turns with a lower number means a faster motor. The turn rating is inversely proportional to the power generated by the motor.

## What do the numbers on a motor mean?

Generally, the first two numbers indicate the diameter of the entire can of the motor OR the diameter of the stator (the inner part of the motor) only. … Similarly, the second pair of numbers can indicate either the height of the entire motor, or only the height of the stator.

## What Kv means?

Answer: “Kv” refers to the constant velocity of a motor (not to be confused with “kV,” the abbreviation for kilovolt). It is measured by the number of revolutions per minute (rpm) that a motor turns when 1V (one volt) is applied with no load attached to that motor.

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## How do you read motor specs?

The RPM listed on the nameplate is the shaft speed for the motor. The speed of the motor is directly related to the frequency of the line voltage and the number of poles in the motor. At 60 Hz, a 4 pole motor will rotate at approximately 1800 RPM (7200/4 poles).

## How do you measure a motor?

Basic mechanical power measurements

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.

## How do I find my motor details without nameplate?

Use a strobe tachometer to determine motor RPM and then set up a generic motor in the database for that RPM. If loading cannot be provided by the operator use the acquired data and RPM to approximate loading. You can view the power factor for a value around 88 to 92 to approximate full load.

## How do you size an electric motor for a pump?

The power required to drive the pump at the rated design condition should always be less than the nameplate horsepower rating of the motor. So if the pump will require 4.5 HP at the design condition, at a minimum, the motor should be sized for 5 HP – the next nominal size above 4.5 HP.

## What is the code for sizing the conductors for a single motor?

Branch-circuit conductors that serve a single motor must have an ampacity of not less than 125% of the motor’s FLC as listed in Tables 430.147 through 430.150 [430.6(A)]. You must select the conductor size from Table 310.16 according to the terminal temperature rating (60°C or 75°C) of the equipment [110.14(C)].

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## What are the factors on which the sizing of electric motors for electric vehicle depends?

Basically, you need to determine the most demanding requirements of your vehicle as well as evaluate how various road conditions will impact performance of the powertrain:

1. Vehicle characteristics. …
2. Driving cycles. …
3. Vehicle configuration (electric, hybrid) …
4. Maximal speed. …
5. Maximal torque. …
6. Maximal power. …
7. Battery Capacity.