Introduction
The Allen-Bradley MPL-B320P-SJ72AA Servo Motor is part of the MP-Series MPL family of low-inertia brushless servo motors. It is designed for industrial motion systems requiring high-speed operation and precise closed-loop control.
The motor combines a 100 mm frame size with a 50.8 mm magnet stack and a 5000 RPM rated speed. This configuration provides a practical solution for machinery requiring relatively high rotational speed without using an excessively large motor.
One of the defining features of the MPL-B320P-SJ72AA is its single-turn high-resolution encoder feedback. The encoder provides detailed position information to the servo drive, allowing the control system to regulate the motor accurately during acceleration, constant-speed operation, deceleration, and positioning.
The motor uses a keyed shaft extension, making it compatible with mechanical systems designed around conventional keyed couplings and transmission components. Correct alignment between the motor shaft and driven equipment remains important to prevent excessive mechanical loading and premature bearing wear.
Unlike the related MPL-B320P-SJ74AA, the SJ72AA configuration does not include a 24 V DC brake. This makes the SJ72AA a suitable choice for applications where the load does not need to be mechanically held by the motor after servo power is removed.
The SpeedTEC DIN right-angle connector is another useful feature for machine builders. Its 180° rotatable configuration provides additional flexibility when routing motor cables in compact equipment.
The MPL-B320P-SJ72AA is also an engineering replacement for certain earlier MPL-B320P configurations, including the discontinued MPL-B320P-HJ72AA. When selecting a replacement, engineers should verify feedback type, shaft configuration, brake requirements, motor voltage, mounting dimensions, and drive compatibility rather than relying only on the frame size.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Manufacturer | Rockwell Automation |
| Product Family | MP-Series MPL |
| Product Type | Rotary Servo Motor |
| Model | MPL-B320P-SJ72AA |
| Motor Type | Low-Inertia Brushless Servo Motor |
| Voltage Class | 480 VAC |
| Armature Voltage | 460 V |
| Frame Size | 100 mm / Frame 3 |
| Magnet Stack Length | 50.8 mm (2.0 in.) |
| Rated Speed | 5000 RPM |
| Continuous Torque | Approx. 3.05 Nm |
| Peak Torque | Approx. 7.91 Nm |
| Continuous Rated Output | Approx. 1.5 kW |
| Feedback | Single-Turn High-Resolution Encoder |
| Feedback Resolution | Sin/Cos, 1024 cycles/rev |
| Feedback Protocol | Hiperface |
| Shaft Configuration | Keyed Shaft Extension |
| Shaft Seal | No Shaft Seal |
| Brake | No Brake |
| Connector | SpeedTEC DIN Right-Angle Connector |
| Connector Rotation | 180° Rotatable |
| Mounting | IEC Metric |
| Mounting Holes | Free Mounting Holes, Type FF |
| Rotor Inertia | Approx. 7.8 × 10⁻⁵ kg·m² |
| Maximum Operating Temperature | 40°C |
| Dimensions | Not specified in the supplied product data |
| Weight | 3.70 kg (8.16 lb) |
| Lifecycle | Active |
Recommended Related Models
The following MPL-B320P models provide useful alternatives when comparing feedback, shaft, and brake configurations:
- MPL-B320P-SJ74AA – Single-turn high-resolution encoder, keyed shaft, 24 V DC brake
- MPL-B320P-RJ72AA – Resolver feedback, keyed shaft, no brake
- MPL-B320P-RJ74AA – Resolver feedback, keyed shaft, 24 V DC brake
- MPL-B320P-RK72AA – Resolver feedback, keyless shaft, no brake
- MPL-B320P-RK74AA – Resolver feedback, keyless shaft, 24 V DC brake
- MPL-B320P-MK72AA – Multi-turn high-resolution feedback, keyless shaft, no brake
- MPL-B320P-MK74AA – Multi-turn high-resolution feedback, keyless shaft, 24 V DC brake
- MPL-B320P-MJ74AA – Multi-turn high-resolution feedback, keyed shaft, 24 V DC brake
- MPL-B320P-SJ24AA – Single-turn high-resolution encoder, keyed shaft, 24 V DC brake
When selecting between these models, the feedback architecture and brake configuration are especially important because they affect both servo-drive compatibility and machine behavior.
Popular Related Models
For Allen-Bradley MP-Series MPL applications, the following models are commonly compared with the MPL-B320P-SJ72AA:
- Allen-Bradley MPL-B320P-SJ74AA – Single-turn encoder, keyed shaft, 24 V DC brake
- Allen-Bradley MPL-B320P-RJ72AA – Resolver, keyed shaft, no brake
- Allen-Bradley MPL-B320P-RJ74AA – Resolver, keyed shaft, 24 V DC brake
- Allen-Bradley MPL-B320P-RK72AA – Resolver, keyless shaft, no brake
- Allen-Bradley MPL-B320P-RK74AA – Resolver, keyless shaft, 24 V DC brake
- Allen-Bradley MPL-B320P-MK72AA – Multi-turn absolute feedback, keyless shaft, no brake
- Allen-Bradley MPL-B320P-MK74AA – Multi-turn absolute feedback, keyless shaft, 24 V DC brake
- Allen-Bradley MPL-B320P-MJ74AA – Multi-turn absolute feedback, keyed shaft, 24 V DC brake
For replacement applications, verify the 460 V armature rating, 100 mm frame, 50.8 mm stack length, 5000 RPM speed, single-turn encoder, keyed shaft, and no-brake configuration before ordering. These details are more important than frame size alone when determining whether another servo motor is a suitable replacement.
