# How do you read motor specs?

Contents

## How do you read a motor nameplate?

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).

## What do motor frame numbers mean?

The frame number relates to the “D” dimension (distance from center of shaft to center bottom of mount). For example, in the two-digit 56 frame, the “D” dimension is 31/2”, 56 divided by 16 = 31/2”. For the “D” dimension of a three-digit frame number, consider only the first two digits and use the divisor 4.

## How do you calculate motor specification?

The required torque is calculated by multiplying the sum of load torque and acceleration torque by the safety factor. When the required torque for the motor varies over time, determine if the motor can be used by calculating the effective load torque.

## How can you tell if a motor is VFD?

Three major factors should be considered when determining if a motor is compatible with a VFD: the motor winding insulation, motor bearings and pump operating speed range.

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## Which power is mentioned on a name plate of a motor * 1 point?

Current. Current indicated on the nameplate corresponds to the rated power output together with voltage and frequency. Current may deviate from the nameplate amperes if the phases are unbalanced or if the voltage turns out to be lower than indicated.

## What does SFA mean on motor?

Service Factor Amps, or S.F.A., represents the amount of current the motor will draw when running at the full Service Factor. In the example nameplate, the S.F.A. is eight amps at 230 volts. Continually exceeding the S.F.A.

## What size is a 48 frame motor?

NEMA electrical motor frame dimensions

NEMA Frame Designation Frame Dimensions (inches)
D E
42 2 5/8 1 3/4
42C 2 5/8 1 3/4
48 3 2 1/8

## What are motor frame sizes?

The frame sizes normally associated with fractional horsepower motors are 42, 48, and 56. In this case, each frame size designates a particular shaft height, shaft diameter, and face or base mounting hole pattern. In these motors, specific frame assignments do not relate to horsepower and speed.

## What is a 56 frame motor?

Specifically “Frame” refers to the diameter of the armature in the motor. Although 2 motors may have the same horsepower rating, a 56-Frame motor will be 40% larger. It will also run cooler and last longer.

## How do I calculate RPM?

RPM = a/360 * fz * 60

RPM = Revolutions per minute. Example 1: Drive step resolution is set for 1000 steps per revolution. Example 2: Drive step resolution is set for 500 steps per revolution. With input frequency of 1000hz, .

## How is motor RPM calculated?

How to Calculate Motor RPM. To calculate RPM for an AC induction motor, you multiply the frequency in Hertz (Hz) by 60 — for the number of seconds in a minute — by two for the negative and positive pulses in a cycle. You then divide by the number of poles the motor has: (Hz x 60 x 2) / number of poles = no-load RPM.

## What is motor torque formula?

These equations are for estimation only, friction, windage, and other factors are not taken into consideration. Calculator-1. Known variables: Horse Power and Speed in RPM. Torque is the action of a force producing or tending to produce rotation. Torque = force x distance. 