Motor torque changes with the speed.
Electric motor rpm formula.
Poles number of poles of your motor.
1 ft lb f 1 356 nm.
Hz frequency or cycles sec.
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.
T ftlb p hp 5252 n 1b.
Note that when an ac motor is loaded the spinning magnetic field in the stator does not change speed.
T inlb p hp 63025 n 1.
50hz is the most common frequency outside the us.
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.
So for example if you have a 4 pole motor on 60 hz then rpm 60 2 4 60 1800 rpm.
50 x 60 x 2 6 000 no load rpm ã number of poles.
Acthree phase induction motorrpmis determined by the formula.
Calculating the rpm resulting from a motor and speed reducer assembly requires only basic mathematical knowledge.
At 1800 rpm a motor develops a 3 lb ft.
Per hp at 575 volts a 3 phase motor draws 1 amp per hp at 460 volts a 3 phase motor draws 1 25 amp per hp at 230 volts a 3 phase motor draws 2 5 amp per hp at 230 volts a single phase motor draws 5 amp per hp.
Since the number of poles of athree phaseinduction motoris established when it is manufactured the only way to change the speed of the motor is to change thefrequency.
Rpm shaft rotation speed or revolutions per minute.
T inlb torque in lb f.
I input dc current.
Here omega ω is equal to 2 x pi x n rpm 60.
V input dc voltage.
Hence motor torque t p ω.
In our example input electrical power of the motor is 0 22 a x 6 v 1 32 w output mechanical power is 1000 rpm x 2 x 3 14 x 0 00126 n m 60 0 132 w.
At no load you have maximum speed and zero torque.
Rpm 120 frequency of poles in the motor.
T ftlb torque lb f ft.
For a 50 hz system the formula would be.
For calculating torque for dc motor.
60hz is the most common frequency in the us.
For dc motor torque formula.
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.
The speed of the motor can be found by using speed measurement devices.
T v x i 2 x pi x n rpm 60 n rpm is the speed of the motor.
Electrical motor power velocity and torque equations.
1750 rpm 1000 rpm 3 5 inches d 2 d 2 6 125 inches.
Check the circle next to the item you are solving for and enter the remain three items in the spaces provided.
Pulley and speed calculator.
Torque in imperial units can be calculated as.
Per hp at 1200 rpm a motor develops a 4 5 lb ft.
P hp horsepower delivered by the electric motor hp.
