B&R 8MSA2S.R0-K4 Servo Motor 6000 RPM Resolver

Description

Product Introduction & Engineering Value

The B&R 8MSA2S.R0-K4 is a compact 8MS series synchronous servo motor designed for fast-response motion applications where installation space is limited. The motor uses permanent magnet technology, resolver feedback, and ACOPOS drive compatibility for precise closed-loop positioning.

Small servo motors often control the most demanding machine movements. A failure in an indexing, feeder, or positioning axis can stop an entire production sequence. Matching the exact motor configuration, feedback type, and mechanical dimensions is critical when replacing an installed unit.

 

Technical Specifications

Specification	Details
Manufacturer	B&R Industrial Automation
Model Number	8MSA2S.R0-K4
Motor Series	8MS
Motor Type	Three-phase permanent magnet synchronous servo motor
Frame Size	2
Length Code	S (Short)
Rated Speed	6000 rpm
Maximum Speed	12000 rpm
Rated Torque	0.18 Nm
Stall Torque	0.20 Nm
Peak Torque	0.80 Nm
Feedback System	Resolver
Cooling Method	Self-cooled
Mounting	Flange mounting
Flange Size	60 × 60 mm
Shaft Diameter	14 mm
Recommended Drive Family	B&R ACOPOS servo drives

 

Field Application & The “Trench” Experience

A semiconductor equipment manufacturer experienced repeated positioning alarms on a small indexing mechanism. The machine cycle depended on a compact servo axis moving a lightweight carrier with high repeatability.

Maintenance engineers first checked the mechanical slide assembly because the error appeared only during rapid acceleration. The mechanical components were within tolerance.

Further inspection showed unstable resolver feedback from the aging servo motor. The original motor was replaced with a tested B&R 8MSA2S.R0-K4, followed by ACOPOS parameter verification and motion testing. The axis returned to stable operation.

The field lesson: small servo motors are easy to underestimate. A low-power axis can still be production-critical.

Typical application scenarios:

• Electronic component placement equipment
• Compact packaging indexing stations
• Precision feeder mechanisms
• Laboratory automation systems
• Small robotic positioning axes

Transparency SOP: QA & Testing

Servo motor inventory requires more than a visual inspection.

Qualification process:

1. Model Verification

• Confirm B&R identification label.
• Verify complete order code: 8MSA2S.R0-K4.
• Check feedback and connector configuration.

2. Mechanical Inspection

• Inspect shaft condition.
• Check flange mounting surface.
• Verify bearing movement.
• Examine housing for impact damage.

3. Electrical Testing

• Measure winding resistance.
• Check insulation resistance.
• Verify phase balance.
• Test temperature sensor circuit.

4. Resolver Validation

• Confirm resolver excitation.
• Verify feedback signal quality.
• Check position response.

5. Drive Test

• Connect to compatible ACOPOS system.
• Perform motor recognition.
• Verify rotation direction.
• Confirm speed response.

6. Inventory Release

Documentation includes:

• Serial number
• Test measurements
• Condition grading
• Warranty status

Available conditions:

• New Surplus
• Refurbished
• Tested Used

 

The Veteran’s Tech Trap Guide

⚠️ Trap #1: Ordering by Frame Size Only

The 8MS family contains multiple motor variants.

Confirm:

• Length code
• Resolver/encoder option
• Torque rating
• Brake configuration

A size 2 motor is not automatically interchangeable with another size 2 unit.

⚠️ Trap #2: Ignoring Resolver Compatibility

The 8MSA2S.R0-K4 uses resolver feedback.

Before installation, verify:

• ACOPOS drive feedback interface
• Existing motor parameters
• Axis commissioning data

PRO TIP: Save the original drive configuration before removing the failed motor.

⚠️ Trap #3: Incorrect Mechanical Assumptions

Compact servo motors often fit into tight assemblies.

Check:

• Shaft length
• Coupling type
• Mounting orientation
• Cable routing

A replacement motor can be electrically correct but mechanically unsuitable.

 

Dynamic FAQ

Q1. What is the B&R 8MSA2S.R0-K4 used for?

The B&R 8MSA2S.R0-K4 is a compact synchronous servo motor used for precision motion control applications with B&R ACOPOS servo systems.

Q2. What are the main ratings of the 8MSA2S.R0-K4?

Typical ratings for the 8MSA2S motor family include:

• Rated speed: 6000 rpm
• Rated torque: approximately 0.18 Nm
• Peak torque: approximately 0.80 Nm
• Maximum speed: 12000 rpm

Q3. What feedback system does this motor use?

The 8MSA2S.R0-K4 uses resolver feedback for closed-loop speed and position control.

Q4. Which drive system is compatible with this motor?

This motor is designed for use with B&R ACOPOS servo drives. Drive selection depends on motor current requirements and application load profile.

Q5. What should buyers verify before purchasing a New Surplus 8MSA2S.R0-K4?

Recommended verification points:

• Exact B&R part number
• Resolver compatibility
• ACOPOS drive matching
• Shaft dimensions
• Motor winding test results
• Mechanical condition
• Warranty coverage

Q6. Can a refurbished 8MSA2S.R0-K4 be used in production machinery?

Yes. A refurbished unit should pass insulation testing, resolver verification, mechanical inspection, and operational testing before being installed on production equipment.