Electric Motor Speed Formula

Using this formula you can see that a four pole motor operating on the bench under no load conditions runs at 1 800 rpm 7 200 ã 4 poles.

Electric motor speed formula.

P number of poles. The rotor speed of a 4 pole induction motor at 50 hz is 1200 r min. F supply frequency hz. The number of poles in the motor winding.

N f 2 p 60 1. Poles number of poles of your motor. F frequency of electrical power supply hz cycles sec 1 s. Calculating the rpm resulting from a motor and speed reducer assembly requires only basic mathematical knowledge.

It is motor speed and torque the turning force of the motor. Slip of a motor can be found from the formula. The power produced by the motor depends on the speed of the motor and is. Note an induction motor will never reach its.

The motor speed calculator calculates the synchronous motor speed from the following parameters. 50hz is the most common frequency outside the us. Where η sync 120 50 4 1500 r min. Normally at it s top at operating speed.

Output mechanical power of the motor could be calculated by using the following formula. Motors run at a specific revolutions per minute rpm and a speed reducer is needed if you want to keep that motor but have a lower rpm. η sync speed of magnetic field. The power supply frequency and.

For example 2 or 4. η m mechanical shaft speed. The torque is the twisting force that makes the motor running and the torque is active from 0 to 100 operating speed. So for example if you have a 4 pole motor on 60 hz then rpm 60 2 4 60 1800 rpm.

Typical no load or synchronous speeds for an ac fractional horsepower motor are 1800 or 3600 rpm and 1000 5000 rpm for dc fractional hp motors. Hz frequency or cycles sec. The synchronous speed can be calculated as. Zero at 0 speed and.

Where p out output power measured in watts w. 50 x 60 x 2 6 000 no load rpm ã number of poles. N shaft rotation speed rev min rpm. Rpm shaft rotation speed or revolutions per minute.

Motors supposed to do some work and two important values define how powerful the motor is. Dc controls adjust speed by varying the voltage sent to the motor this differs from ac motor controls which adjust the line frequency to the motor. P number of poles. Note that when an ac motor is loaded the spinning magnetic field in the stator does not change speed.

60hz is the most common frequency in the us. For example 50 hz or 60 hz. Rotor speed η m 1200 r min. This can be found on the nameplate of the motor.

S η sync η m η sync 100. A four polethree phase induction motorwhen operated at 60 hz will be very close to 1800rpm synchronous speed the rated full load speed will be less than synchronous speed by the value of slip a four polethree phase induction motorwith a ratedfull loadspeed of 1750 has a slip rating of 2 7 by formula. P out τ ω. The synchronous speed for an electric induction motor is determined by.