Introduction
The Allen-Bradley MPL-B320P-RJ74AA is an MP-Series MPL low-inertia brushless rotary servo motor designed for industrial automation systems requiring controlled speed, accurate positioning, and reliable feedback.
The motor uses a 460 V motor class, 100 mm Frame 3 housing, and 50.8 mm magnet stack. With a 5000 RPM rated speed, it provides a practical combination of high-speed operation and torque capability for demanding machine axes.
The low-inertia design allows the motor to respond quickly to changes in speed and position commands. This characteristic is particularly valuable in machinery that repeatedly accelerates, decelerates, stops, and reverses direction.
The MPL-B320P-RJ74AA uses a 2-pole resolver for feedback. Resolver feedback provides rotor-position information to the servo control system and is well suited to industrial environments. When replacing an existing motor, the feedback technology must be verified carefully because resolver and encoder configurations require compatible drive hardware and configuration.
The motor also incorporates a 24 V DC holding brake. The brake can help mechanically hold the shaft when the servo system is disabled or when the application requires additional holding capability. Brake operation should be coordinated correctly with the servo drive and machine-control sequence.
A keyed shaft extension is provided for mechanical transmission. This configuration is useful when connecting the motor to couplings, gears, pulleys, or other driven machine components designed for keyed shafts.
The motor uses a SpeedTEC DIN right-angle connector with a 180° rotatable configuration. This provides installation flexibility and can simplify cable routing in machine enclosures.
The 100 mm Frame 3 and 50.8 mm magnet stack make the MPL-B320P-RJ74AA suitable for applications requiring more motor capacity than smaller MPL configurations. Its low-inertia construction also supports responsive motion control in applications involving frequent speed changes.
For replacement and retrofit projects, the complete catalog number should always be checked. Frame size alone is not sufficient for selecting a compatible servo motor. Voltage class, feedback type, brake configuration, shaft style, stack length, connector arrangement, and servo-drive compatibility should all be confirmed before installation.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Manufacturer | Rockwell Automation |
| Model | MPL-B320P-RJ74AA |
| Product Family | MP-Series MPL |
| Product Type | 480V AC Rotary Servo Motor |
| Motor Design | Low-Inertia Brushless Servo Motor |
| Voltage Class | 460 V AC |
| Frame Size | 100 mm |
| Frame Designation | Frame 3 |
| Magnet Stack Length | 50.8 mm (2.0 in.) |
| Stack Designation | Stack Length 20 |
| Rated Speed | 5000 RPM |
| Feedback Type | 2-Pole Resolver |
| Continuous Torque | Approximately 3.05 Nm |
| Shaft Type | Keyed Shaft Extension |
| Shaft Seal | No Shaft Seal |
| Connector | SpeedTEC DIN Right-Angle Connector |
| Connector Rotation | 180° Rotatable |
| Brake | 24 V DC Holding Brake |
| Mounting | IEC Metric, Free Mounting Holes Type FF |
| Enclosure | IP50 standard |
| Dimensions | Not specified in the supplied data |
| Weight | 3.70 kg (8.16 lb) |
| Application | Industrial Servo Motion Control |
Recommended Related Models
- Allen-Bradley MPL-B320P-RJ72AA — 100 mm Frame 3 servo motor with resolver feedback and no brake.
- Allen-Bradley MPL-B320P-MK74AA — 100 mm Frame 3 servo motor with multi-turn high-resolution absolute feedback, keyed shaft, and 24 V DC brake.
- Allen-Bradley MPL-B320P-MJ74AA — 100 mm Frame 3 servo motor with multi-turn high-resolution absolute feedback and 24 V DC brake.
- Allen-Bradley MPL-B320P-SJ74AA — 100 mm Frame 3 servo motor with single-turn high-resolution encoder and 24 V DC brake.
- Allen-Bradley MPL-B320P-RK74AA — 100 mm Frame 3 resolver-feedback motor with keyless shaft and 24 V DC brake.
Popular Related Models
- Allen-Bradley MPL-B320P-RJ72AA — Resolver-feedback version without the integrated 24 V DC brake.
- Allen-Bradley MPL-B320P-MK74AA — Multi-turn absolute-feedback version with keyed shaft and brake.
- Allen-Bradley MPL-B320P-MK72AA — Multi-turn absolute-feedback version with keyed shaft and no brake.
- Allen-Bradley MPL-B320P-SJ74AA — Single-turn high-resolution encoder version with keyed shaft and brake.
- Allen-Bradley MPL-B320P-SJ72AA — Single-turn high-resolution encoder version without brake.
- Allen-Bradley MPL-B320P-RK74AA — Resolver-feedback version using a keyless shaft and 24 V DC brake.
