Overview
The Allen-Bradley MPL-B420P-MJ72AA is an MP-Series low-inertia rotary servo motor designed for high-precision motion control applications. Part of the Kinetix family, this 460V AC servo motor delivers 1.9 kW continuous power at 5000 RPM with excellent torque density and minimal rotor inertia, making it ideal for dynamic positioning and speed-critical applications in industrial automation systems.
Key Features
- Low-Inertia Design: Rotor inertia of 0.00026 kg·m² enables rapid acceleration and precise positioning control
- Multi-Turn Encoder: High-resolution feedback with on-board Smart Motor Technology for automatic system identification and reduced commissioning time
- Compact Frame Size: Frame 4 with 115 mm (4.53 in.) housing and keyed shaft for space-constrained applications
- High Torque Density: Peak stall torque of 13.5 Nm, continuous stall torque of 4.74 Nm delivers responsive motion control
- SpeedTEC Connector: Circular DIN connector with 180° rotatable right-angle orientation for flexible cable routing
- Industrial-Grade Construction: Brushless AC synchronous design with improved winding insulation for enhanced thermal performance
Technical Specifications
Motor Performance:
- Catalog Number: MPL-B420P-MJ72AA
- Series: Kinetix MP (MP-Series Low-Inertia Servo)
- Input Voltage: 460V AC three-phase
- Rated Speed: 5000 RPM
- Rated Output Power: 1.9 kW
- Peak Stall Torque: 13.5 Nm (120 lb-in)
- Continuous Stall Torque: 4.74 Nm (42 lb-in)
- Peak Stall Current: 22.0 A
- Continuous Stall Current: 6.4 A
- Rotor Inertia: 0.00026 kg·m²
Physical & Electrical:
- Frame Size: 4 (115 mm / 4.53 in. outer diameter)
- Magnet Stack Length: 50.8 mm (2.0 in.)
- Shaft: Keyed extension, IEC metric standard
- Mounting: IEC metric, Free Mounting Holes (Type FF)
- Connector: Circular SpeedTEC DIN, right angle, 180° rotatable
- Feedback: Multi-turn high-resolution encoder
- Brake: Not included (optional external brake available)
- Operating Temperature: 0°C to 40°C
Typical Applications
The MPL-B420P-MJ72AA excels in applications requiring fast response and precise positioning:
- Automated assembly machinery and pick-and-place systems
- Packaging and labeling equipment with high throughput demands
- Printing systems and graphic arts machinery
- Robotics and precision XY table control
- Spindle and tool-changer drives in machine tools
- Process control systems requiring synchronized multi-axis motion
Compatibility & Replacements
Compatible With
- Allen-Bradley Kinetix 2000, 6000, and 7000 drive families
- Ultra 3000 servo amplifier systems
- EtherNet/IP motion control networks
- Studio 5000 logix programming environment
- IEC-flange mounted industrial servo drive systems with SpeedTEC connectors
Replaces / Drop-In Replacement For
This motor maintains dimensional and electrical compatibility with earlier versions of the MPL-B420P frame. Verify specific revision and magnet stack requirements with your system integrator before ordering, as suffix codes (-MJ72AA) indicate specific encoder and connector configurations.
Works With
- Rockwell Automation Studio 5000 / Allen-Bradley Logix controllers
- FactoryTalk Motion diagnostics software
- EtherNet/IP protocol for networked motion control
- Safe Torque Off (STO) compatible drive systems
- PROFINET-enabled Kinetix drives with gateway modules




