Product Core Brief

• Model: 8MSA3L.E0-31
• Brand: B&R Industrial Automation
• Series: 8MS Slim Natural-Cooled Synchronous Servo Motor Line
• Core Function: Delivers fast closed-loop speed, position and torque control for small-format packaging, electronics assembly and textile axes
• Product Type: 3-Phase Permanent Magnet Synchronous Servo Motor, resolver feedback, no integrated holding brake
• Key Specs: 4500 rpm nominal speed | 2.0Nm rated torque | Analog resolver feedback | Straight fixed circular connectors
• Note: New Original stock; matched ACOPOS P3 / ACOPOSmulti servo drives sold separately

Key Technical Specifications

• Rated Power: 0.94 kW
• Nominal Speed: 4500 rpm; Max Mechanical Speed: 12000 rpm
• Rated Torque: 2.0 Nm; Stall Torque: 2.5 Nm; Peak Torque: 6.2 Nm
• Feedback System: Analog sine/cosine resolver, no absolute position memory without homing
• Cooling Method: Passive natural convection slim frame construction
• Insulation Class: Class F; Continuous operating ambient range -20°C to +60°C
• Enclosure Rating: IP64 shaft and connector end; IP54 rear housing
• Winding Supply: 3×230VAC servo drive supply class
• Mechanical Mount: Standard compact IEC square flange, smooth keyless output shaft
• Connectors: Separate fixed Intercontec circular plugs for power and resolver signal lines
• Rotor Moment of Inertia: 7.4 kg·cm²
• Unit Weight: 3.78 kg (brake-less variant)
• Thermal Time Constant: 11 min natural convection heat dissipation
• Certifications: CE, UL cULus, EAC, RoHS industrial compliance

Product Introduction

This compact frame resolver servo targets high-cycle small automation axes where analog feedback rejects EMI noise from nearby inverter and drive wiring. Fixed straight circular connectors simplify tight cabinet cable routing without rotating joint wear points.

The unit’s fanless cooling eliminates mechanical wear failures, while resolver auto-identification cuts commissioning steps when paired with compatible drive hardware. Absence of an integrated brake shortens overall motor length for narrow machine frame layouts.

QA & Testing SOP (Transparency Building)

1. Incoming Inspection: Cross-reference OEM serial database for genuine hardware validation; inspect output shaft surface for scoring, circular connector pins for bending, and cast aluminum housing for casting voids.
2. Live Testing: Couple the unit to calibrated dynamometer; supply 3×230VAC from matched ACOPOS P3 drive; run 24-hour cyclic load test at 75% rated torque, logging resolver position ripple and steady-state speed error hourly.
3. Electrical Testing: 500V Megger insulation test between stator windings and motor housing; pass threshold >10MΩ isolation resistance.
4. Firmware/Config Backup: Capture resolver winding ID via Automation Studio; photograph power/feedback connector pinout and shaft orientation for replacement matching.
5. Final QC & Packaging: Apply thin anti-corrosion protective film to output shaft; secure inside shock-absorbent ESD crate; attach printed test tag with dynamometer torque curve trace data.

Installation Pitfalls & Guide (Engineer to Engineer)

❗ Digital Encoder Drive Mismatch: Resolver-only hardware cannot connect to drives built exclusively for EnDat digital encoders; pairing triggers persistent feedback NOT OK faults at drive power-up.❗ Shaft Seal Damage During Coupling Fit: Hammer strikes to the motor output shaft crack front IP64 oil seal, allowing cutting fluid ingress that shorts stator windings within weeks of runtime. Use only hydraulic press-fit tooling for couplings.❗ Parallel Cable Routing Noise: Running resolver signal cables alongside high-current motor power wiring creates analog signal distortion, generating ±8 count position jitter during high-speed contouring cycles.❗ Over-tightened Fixed Connector Strain Relief: Excessive clamp force on straight circular cable glands crushes internal twisted shield pairs and degrades resolver signal noise immunity.❗ Unmitigated ESD Exposure: Low-humidity static discharges damage resolver analog signal circuitry; wear grounded anti-static wristbands before mating circular feedback connectors.

4-Step Replacement Guide

1. Pre-install: Full machine power down; photograph power/resolver connector pinouts, coupling gap dimensions, and cable bend routing for exact replication.
2. Removal: Loosen coupling clamping fasteners; disconnect both fixed circular plugs; unbolt flange mounting hardware and extract the unit from machine frame.
3. Install: Secure new unit to flange with OEM specified torque values; press-fit coupling without shaft impact; set cable strain relief to moderate tension before final fastening.
4. Power-on Test: Execute auto motor identification routine in Automation Studio; run low-speed jog cycles; verify stable resolver position readings before full production speed operation.

FAQ (Frequently Asked Questions)

Q: Does the resolver retain absolute position after full power loss?A: No. Resolver only outputs relative analog position data. Every power cycle requires a full homing sequence to re-establish machine zero position, unlike multi-turn absolute encoder motor variants.Q: Can this unit sustain continuous operation at peak 6.2Nm torque?A: No. Peak torque is limited to brief acceleration/deceleration duty cycles (<5% total runtime). Sustained torque above rated 2.0Nm exceeds Class F insulation thermal limits and accelerates winding degradation.Q: Which ACOPOS drive families fully support resolver feedback?A: ACOPOS P3 8EI-series and ACOPOSmulti 8BVI-series drives. Older first-gen ACOPOS 1045/1090 units lack native resolver signal processing logic.Q: Is this brake-less unit safe for vertical Z-axis lifting loads?A: Not for safety-critical vertical axes. This variant has no integrated holding brake; uncontrolled load drop will occur during power loss. Specify D-suffix braked motor models for vertical applications.Q: What ambient temperature triggers continuous torque derating?A: Torque output derates linearly above +45°C cabinet ambient; at max +60°C operating temperature, continuous rated output falls to 75% of nominal 2.0Nm torque.Q: Are generic third-party circular motor cables compatible with fixed straight connectors?A: Physically compatible, but uncertified cables lack full EMC twisted shielding. Field data shows 3.7x higher resolver signal noise with non-B&R cabling during high-speed motion.Q: What warranty coverage applies to surplus stock of the motor?A: Standard 12-month functional warranty covers stator winding and resolver manufacturing defects; damage from coupling impact, coolant ingress, or unshielded wiring-induced signal failure is fully excluded from coverage.