The adjustable-height PoleStar rotates the motor shaft at constant speeds (ranging from 0 to 1,000 RPM) for faster, hands-free operation and to measure the Back Electro-motive Force (BEMF).

Included: Make quick connections with the 6 pc. L-JAW HUB Kit or 1 pc. 3-JAW CHUCK .

What is Back Electro-motive Force (BEMF)?

Back EMF is the voltage generated when a permanent magnet motor is rotated. This "kick-back" or counterforce is called Back Electro-motive Force or Back-EMF (BEMF).

Why Measure the Back EMF at 1000 RPM?

Measure the Back Electro-motive Force to check the rotor's magnetic strength and winding condition.

1. Connect the motor to PoleStar with a coupling
2. Make sure it is level so that the motor is not damaged
3. Set PoleStar to 1000 RPMs
4. While the motor is running, measure UVW phase-to-phase