Introduction
The Allen-Bradley MPL-B320P-SJ74AA Servo Motor is an MP-Series MPL low-inertia brushless servo motor designed for demanding industrial motion applications. Its configuration combines a 100 mm Frame 3, 50.8 mm magnet stack, 5000 RPM speed rating, single-turn high-resolution encoder feedback, keyed shaft, and 24 V DC brake.
The motor is specified with a 460 V armature voltage and belongs to the 480 VAC-class MPL motor family. It provides approximately 3.05 Nm of continuous torque and approximately 7.91 Nm of peak torque, with a continuous rated output of approximately 1.5 kW.
One of the key characteristics of the MPL-B320P-SJ74AA is its single-turn high-resolution encoder. The encoder uses Sin/Cos feedback with 1024 cycles per revolution and Hiperface protocol. This provides the servo control system with detailed rotor-position information for accurate velocity and position control.
The keyed shaft extension provides a conventional mechanical interface for compatible couplings, pulleys, gears, and other transmission components. During installation, shaft alignment and allowable radial and axial loads should be considered carefully to protect the motor bearings and maintain stable servo performance.
The integrated 24 V DC brake makes the SJ74AA especially useful for vertical and gravity-loaded axes. The brake is primarily intended to hold the motor shaft when the servo is de-energized rather than to serve as the normal dynamic stopping mechanism. The complete machine safety and stopping strategy should therefore be designed separately.
The motor uses a SpeedTEC DIN right-angle connector that can rotate through 180°. This feature allows cable routing to be adapted to the machine structure and can be particularly useful where space around the motor is limited.
The MPL-B320P-SJ74AA is an active product configuration and is also identified as an engineering replacement for certain older MPL-B320P motor configurations. When selecting a replacement, engineers should verify the complete catalog number, feedback type, shaft arrangement, brake option, voltage, mounting configuration, and drive compatibility.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Allen-Bradley |
| Manufacturer | Rockwell Automation |
| Product Family | MP-Series MPL |
| Product Type | Rotary Servo Motor |
| Model | MPL-B320P-SJ74AA |
| 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 |
| Maximum 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 | 24 V DC Brake |
| Connector | SpeedTEC DIN Right-Angle Connector |
| Connector Rotation | 180° Rotatable |
| Mounting | IEC Metric |
| Mounting Holes | Free Mounting Holes, Type FF |
| Rotor Inertia | Approx. 9.2 × 10⁻⁵ kg·m² |
| Operating Temperature | Up to 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 are useful when comparing feedback, shaft, and brake configurations:
- MPL-B320P-SJ72AA – Single-turn high-resolution encoder, keyed shaft, no brake
- MPL-B320P-SJ24AA – 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
The MPL-B320P-SJ72AA is one of the closest configuration comparisons because it uses the same single-turn encoder and keyed shaft but does not include the 24 V DC brake.
Popular Related Models
For Allen-Bradley MP-Series MPL servo applications, the following models are commonly compared with the MPL-B320P-SJ74AA:
- Allen-Bradley MPL-B320P-SJ72AA – Single-turn encoder, keyed shaft, no 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 high-resolution feedback, keyless shaft, no brake
- Allen-Bradley MPL-B320P-MK74AA – Multi-turn high-resolution feedback, keyless shaft, 24 V DC brake
- Allen-Bradley MPL-B320P-MJ74AA – Multi-turn high-resolution feedback, keyed shaft, 24 V DC brake
For replacement applications, verify the 460 V armature voltage, 100 mm frame, 50.8 mm magnet stack, 5000 RPM rating, single-turn encoder, keyed shaft, 24 V DC brake, and SpeedTEC DIN connector configuration before selecting an alternative motor.
