Product Description:

The S33NRYY-LDN-NS-00 synchronous step motor is produced by Pacific Scientific as part of the Powersync Synchronous Motors series. In motion-control systems, this NEMA 34 class unit converts commanded step sequences from a drive into precise low-speed rotation for indexing conveyors, rotary tables, or packaging axes. By stepping through discrete pole detents rather than relying on slip, the motor holds position without encoder feedback, making it suitable for applications where open-loop torque margin is acceptable.

Electrical performance centers on a single-phase stator winding that accepts an input of 120 Vac at the standard 60 Hz line frequency through a 3-lead configuration. The winding presents a resistance of 32 Ohms and an inductance of 362 mH, which influence current rise time and step response. At 80% of pull-out torque, the motor draws 0.78 Arms/phase, while full pull-out torque reaches 1015 oz-in before synchronism is lost. When operated at its synchronous speed of 72 RPM, the shaft can deliver continuous output without lost steps. Thermal energy moves from the copper to the frame across a 1.6 °C/W path, and the three stacked rotors limit reflected inertia to 0.53 oz-in-s² so drive current is not spent accelerating unnecessary mass.

Mechanically, the motor uses a NEMA 34 square frame measuring 3.38 inches on each side, with a single output shaft for direct coupling. Rated torque capability is 690 oz-in, which leaves margin above the 54 oz-in detent holding torque during position holding and startup. The low rotor inertia of 0.0567 oz-in-s² improves start-stop responsiveness, which is useful when the system must index rapidly between positions. Overall device mass is 11.9 lb, and the compact housing dissipates heat through the aluminum enclosure without auxiliary cooling. A three-stack rotor core works with the magnetic detents to stabilize position during power-off, and the 3.38-inch profile fits common motor mounts used in automation equipment.