Product Description:

The PMB33C-20201-02 is a brushless servomotor manufactured by Pacific Scientific as part of the PMB Brushless Servomotors series. It is intended for closed-loop motion axes in packaging, material-handling, and light machine-tool equipment, where it converts commanded electrical energy into regulated rotary torque. The motor interfaces with servo drives that modulate phase current based on feedback, allowing the axis to hold position, accelerate accurately, and settle quickly within automated production sequences. This closed-loop arrangement lets the drive correct for load changes in real time and maintain stable motion through repeated starts and stops.

Its frame conforms to NEMA Size 34, giving a 3.4-inch square mounting face that aligns with standard gearboxes and machinery brackets. The nominal stall current at 240 VAC is limited to 3.8 ARMS, enabling medium-power servo amplifiers to deliver full static torque without excessive heating. Motor power, feedback, and ground conductors emerge as flying leads with MS connectors, which keeps the housing end compact and allows direct connection to matching harnesses. Rotor position information is provided by an internal Hall sensor, giving the drive the rotor sector data needed for proper phase commutation at startup and during low-speed operation. Mechanical power is transmitted through a shaft machined with a square key, which helps prevent rotational slip between the motor and the coupled load.

Thermal protection is supplied by a PTC thermistor, which shows a sharp rise in resistance near its trip point so the drive can reduce current before winding temperatures climb too high. Continuous torque capability is increased by a stack length multiple of 3, providing a longer magnetic path without changing the external mounting envelope. That longer active length helps raise sustained output within the same frame size when installation space is limited. The added thermal monitoring also helps the motor remain within its intended operating range during repeated acceleration, dwell, and indexing cycles.