# What is the Power of Stepper Motor?

When purchasing a stepper motor, we will find that there is no power item in the specifications of the stepper motor. When selecting, the selection is based on the torque at the corresponding speed instead of power.

The reason why the power (W) is not marked is because the stepper motor does not have the concept of "rated speed".

What we usually call the power (W) of AC motors and servo motors refers to the power (W) of the motor when running at "rated speed", that is, "rated power". Stepper motors are generally used for speed regulation in a wide range, and their power changes. The power (W) calculated by substituting different speeds will also be different. Therefore, stepper motors do not use power, and generally only torque is used. to measure.

If you wish to select a stepper motor based on output power, the torque and power estimation formula is as follows:

P=ω·T

ω=2·π·n/60

P=2·π·n·T/60=0.1047×n×T

P--Power, unit: Watt (W);

ω--Angular velocity, unit: radians per second (rad/s);

n--Rotation speed per minute, unit: (r/min);

T--Torque, unit: Newton·meter (N·m).

Take the stepper motor 34HS31-6004S as an example, as shown below,

According to the torque curve diagram, it can be seen that when the rotation speed is 300RPM, the torque is 1.25Nm. Put this into the formula:

P=0.1047×n×T=0.1047×300×1.25=39.26W (no safety factor added)

That is, when using the driver DM860T, the driving voltage is 24VDC, the driving current is 6.0A, and the subdivision setting

Set to 2000 pulses/revolution, the mechanical output power of the stepper motor 34HS31-6004S at 300RPM is 39.26W.

The reason why the power (W) is not marked is because the stepper motor does not have the concept of "rated speed".

What we usually call the power (W) of AC motors and servo motors refers to the power (W) of the motor when running at "rated speed", that is, "rated power". Stepper motors are generally used for speed regulation in a wide range, and their power changes. The power (W) calculated by substituting different speeds will also be different. Therefore, stepper motors do not use power, and generally only torque is used. to measure.

If you wish to select a stepper motor based on output power, the torque and power estimation formula is as follows:

P=ω·T

ω=2·π·n/60

P=2·π·n·T/60=0.1047×n×T

P--Power, unit: Watt (W);

ω--Angular velocity, unit: radians per second (rad/s);

n--Rotation speed per minute, unit: (r/min);

T--Torque, unit: Newton·meter (N·m).

Take the stepper motor 34HS31-6004S as an example, as shown below,

According to the torque curve diagram, it can be seen that when the rotation speed is 300RPM, the torque is 1.25Nm. Put this into the formula:

P=0.1047×n×T=0.1047×300×1.25=39.26W (no safety factor added)

That is, when using the driver DM860T, the driving voltage is 24VDC, the driving current is 6.0A, and the subdivision setting

Set to 2000 pulses/revolution, the mechanical output power of the stepper motor 34HS31-6004S at 300RPM is 39.26W.

Updated on: 26/04/2024

Thank you!