Product Description:

The S21GNNA-RNNM-00 is a brushless servo motor produced by Pacific Scientific for the S Brushless Motors series. This unit is a 6-pole brushless servo motor with neodymium magnets, intended to deliver closed-loop torque and velocity control in industrial automation axes such as pick-and-place slides, packaging spindles, or small conveyor drives. When paired with a compatible drive, it converts electrical energy into precisely metered mechanical rotation.

It is rated for a continuous stall torque of 0.5 Nm; that is the steady load the motor can hold without overheating. During acceleration or brief load spikes, the actuator delivers a peak torque of 1.36 Nm, allowing rapid indexing. The electromagnetic conversion efficiency is indicated by its torque constant of 0.3 Nm/ARMS, so each ampere of sinusoidal phase current produces that amount of torque. The back-EMF coefficient of 0.19 VRMS/rad/sec helps determine the amplifier voltage margin required at the target speed. A winding resistance of 12.0 Ohms limits current draw at low speeds, influencing both thermal rise and current-loop response. Together, these electrical values affect the motor's dynamic response and thermal behavior.

The motor follows the NEMA 23 mounting envelope, so it can bolt directly to standardized gearheads or machine plates. Its single-stack construction keeps the length short, while the rotor inertia of 0.042 kgm² x10⁻³ supports fast reversals without excessive drive effort. A weight of 1.4 kg eases installation on lightweight axes. Electrical power and resolver conductors exit through a motor-mounted MS connector, and the primary feedback is a size 21 frameless resolver that delivers continuous position data to the controller. The motor has no integrated brake and no shaft seal. A line-to-line inductance of 14.4 mH smooths current transitions and can reduce acoustic noise when used with high-frequency PWM drives.