B&R 8MSA4M.E3-86 Size 4 Synchronous Servo Motor

Description

Key Technical Specifications

Specification warning: Public sources for this exact model contain contradictory technical data. Wake Industrial describes the motor as a self-cooled 8MS size-4 unit with a 64-minute thermal time constant, approximately 5.6 kg weight, IP65 protection, and maximum speed around 12,000 RPM. Radwell’s exact-model catalog instead identifies 8MSA4M.E3-86 as a 6,000 RPM EnDat multi-turn, 32-line servo motor and confirms that the model is discontinued.

For that reason, values such as rated current, rated torque, rated power, encoder resolution, shaft dimensions, and brake configuration should not be copied from another 8MSA4M variant. Verify them against the motor nameplate and the original B&R motor data before drive replacement or parameter entry.

Product Introduction

The B&R 8MSA4M.E3-86 is a size-4 three-phase synchronous servo motor from the B&R 8MS family. It is intended for closed-loop motion systems using B&R servo drives, with exact-model references identifying an EnDat multi-turn feedback configuration and 6,000 RPM classification.

The motor uses self-cooling and integrated winding temperature monitoring. Its 8MS architecture is suited to machine axes requiring controlled speed, position, and torque. Because this exact model is discontinued, replacement work should focus on matching the complete electrical and mechanical configuration rather than selecting a motor solely by frame size.

8MSA4M.E3-86

8MSA4M.E3-86

Installation & Configuration Guide

Stage 1 — Pre-Installation

Estimated time: 30–60 minutes

1. Place the machine in a controlled maintenance state and notify operations personnel.
2. Apply LOTO to the servo power supply.
3. Verify that the drive DC bus has discharged before touching motor wiring.
4. Record the existing motor’s complete nameplate information.
5. Photograph the motor connector, shaft coupling, mounting position, and cable routing.
6. Back up the machine project and relevant ACOPOS axis parameters.
7. Confirm that the replacement is specifically 8MSA4M.E3-86, not merely another 8MSA4M motor.

⚠️ Do not assume that an apparently identical 8MS motor has the same winding, feedback, speed rating, or brake configuration.

Stage 2 — Remove the Existing Motor

Estimated time: 30–60 minutes

1. Verify electrical isolation with the appropriate test equipment.
2. Disconnect the motor power and feedback connectors.
3. Label the cables if the installation documentation is incomplete.
4. Release the coupling, belt, gearbox, or other mechanical transmission.
5. Support the motor before removing its mounting bolts.
6. Remove the motor without applying impact or bending loads to the shaft.

Retain the original motor until commissioning of the replacement is complete. The old unit provides a useful physical reference for connector orientation, shaft dimensions, and mounting geometry.

Stage 3 — Install the 8MSA4M.E3-86

Estimated time: 45–90 minutes

1. Compare the replacement nameplate with the removed motor.
2. Verify the EnDat feedback configuration before connecting the feedback cable.
3. Confirm the flange, shaft, coupling, and mounting arrangement.
4. Position the motor without forcing the shaft into the coupling.
5. Align the motor and driven machine according to the equipment manufacturer’s tolerances.
6. Tighten mounting hardware to the machine manufacturer’s specified torque.
7. Connect the motor power cable and feedback cable.
8. Verify shielding, grounding, strain relief, and cable bend radius.
9. Confirm that the shaft is free from unintended axial or radial loading.

⚠️ Do not substitute an R0 resolver motor or another encoder variant without checking the ACOPOS configuration. Feedback compatibility is an electrical system requirement, not simply a connector issue.

Stage 4 — Power-On and Testing

Estimated time: 30–90 minutes

1. Verify the ACOPOS drive’s motor configuration before enabling the power stage.
2. Confirm that the feedback device is detected correctly.
3. Check the reported motor position while stationary.
4. Perform a controlled low-speed jog with the machine unloaded where practical.
5. Verify actual direction against commanded direction.
6. Monitor following error, motor current, feedback diagnostics, and drive alarms.
7. Increase speed gradually while checking vibration and mechanical noise.
8. Run the axis through a representative production cycle.
9. Monitor winding temperature during the initial extended run.

The exact-model Wake Industrial record identifies an integrated thermistor for winding temperature monitoring and a 64-minute thermal time constant.

FAQ

Is the B&R 8MSA4M.E3-86 still manufactured?

Available industrial distributor records identify the exact model as discontinued by the manufacturer. It is therefore primarily a legacy replacement, surplus, or repair item.

What feedback does the 8MSA4M.E3-86 use?

Radwell’s exact-model listing identifies it as an EnDat multi-turn, 32-line servo motor. Because public records conflict on some other specifications, the physical nameplate and original machine documentation should be checked before commissioning.

What is the maximum speed?

Radwell identifies the exact model as a 6,000 RPM servo motor. Another distributor page reports approximately 12,000 RPM for this model, demonstrating why the exact nameplate and OEM documentation should be used for final speed limits.

Can I replace it with another B&R 8MSA4M motor?

Not automatically. The replacement must match the winding, feedback technology, speed rating, mechanical dimensions, shaft configuration, brake arrangement, connector configuration, and ACOPOS drive parameters.

Does the motor contain thermal protection?

Yes. Published information for this exact model describes an integrated thermistor in the winding for temperature monitoring.

Does replacing the motor require changing the PLC program?

A direct replacement with the same motor configuration normally does not require rewriting the machine sequence. However, the ACOPOS axis configuration, motor identification, feedback parameters, scaling, direction, and tuning should be verified before production.

What should procurement verify before ordering?

Provide the supplier with the complete 8MSA4M.E3-86 part number, motor nameplate photograph, machine application, existing feedback type, brake requirements, shaft/coupling details, and required condition. For a discontinued motor, request serial/traceability information and functional-test documentation where available.