Product Description:

The S21HNAA-RNNE-00 brushless servo motor is built by Pacific Scientific and belongs to the S Brushless Motors series. As a 6-pole neodymium magnet brushless servo unit, it provides closed-loop speed and position control for machinery axes in industrial automation. The motor integrates directly into NEMA-compatible mounts, allowing it to fit standardized frames while maintaining high torque density for its size. Its resolver feedback and DC holding brake support precise positioning and load-holding functions in pick-and-place, packaging, and small conveyor stations.

At the core of the unit is a continuous stall capability of 0.5 Nm, which is the torque it can supply indefinitely without overheating. For short-duration demands, it produces a peak value of 1.36 Nm, letting the axis overcome inertial loads during acceleration. The electromagnetic circuit presents a line-to-line inductance of 3.7 mH; this limits current ripple and shapes the current loop bandwidth in the drive. A line-to-line resistance of 3.0 Ω establishes the steady-state current draw at a given bus voltage and contributes to copper losses. Torque is generated in proportion to current by a constant of 0.2 Nm/ARMS, giving the drive predictable scaling from commanded amperes to delivered mechanical output.

With a mass of 1.4 kg, the motor adds minimal load to linear stages and supports rapid indexing. The housing follows the NEMA 23 footprint in the NEMA frame standard, so it pairs with widely available gearboxes and brackets. Rotor inertia is 0.042 kg m² × 10⁻³, enabling high acceleration without excessive drive effort, and the back-EMF constant is 0.13 VRMS/rad/sec, which helps the controller estimate speed from voltage feedback. A 24 V DC brake secures the shaft at rest, the size 21 frameless resolver supplies primary position data, and Interconnectron connectors complete the wiring. The motor has no shaft seal or secondary feedback. It has a stack length of one, and winding code H indicates the copper fill.