Product Core Brief

• Model: 8MSA4M.E3-86
• Brand: B&R Industrial Automation
• Series: 8MS Frame 4 Natural-Cooled Synchronous Servo Motor Line
• Core Function: Delivers precise high-dynamic closed-loop speed, position and torque control for mid-load CNC cutting, filling, and high-speed packaging axes
• Product Type: 3-Phase Permanent Magnet Synchronous Servo Motor, EnDat multi-turn absolute encoder, no integrated holding brake
• Key Specs: 4000 rpm nominal speed | 2.9kW rated power | 400V winding class | Reinforced front bearing assembly
• Note: New Original inventory; matched ACOPOS P3 / ACOPOSmulti 400V servo drives sold separately

Key Technical Specifications

• Rated Power: 2.9 kW
• Nominal Speed: 4000 rpm; Max Mechanical Speed: 6000 rpm
• Rated Torque: 6.5 Nm; Peak Torque: 19.5 Nm (3x overload, <5% duty cycle)
• Feedback System: EnDat 2.2 multi-turn absolute encoder, battery-free position retention
• Cooling Method: Passive natural convection, no auxiliary cooling fans
• Insulation Class: Class F; Continuous operating ambient range -15°C to +40°C; torque derating above +40°C
• Enclosure Rating: IP65 shaft and connector end; IP54 rear housing
• Winding Supply: 3×400VAC high-voltage servo drive supply class
• Mechanical Mount: Standard IEC square flange, smooth keyless output shaft
• Bearing Spec: Reinforced front bearing, max radial load 700 N, max axial load 350 N
• Connectors: Separate angled swivel Intercontec circular plugs for power and encoder signals
• Rotor Moment of Inertia: 18.3 kg·cm²
• Unit Weight: 5.6 kg (brake-less variant)
• Thermal Time Constant: 15 min natural convection heat dissipation
• Certifications: CE, UL cULus, EAC, RoHS industrial compliance

Product Introduction

This medium-frame high-voltage absolute encoder servo targets mid-load continuous motion axes where battery-free multi-turn tracking eliminates periodic encoder cell replacement downtime. Swivel angled connectors simplify tight cabinet cable routing without sharp bend-induced signal attenuation.

The reinforced front bearing extends service life on axes with heavy radial cutting or forming loads, while passive cooling removes fan clogging failure points common in dusty production environments. Absolute position data removes mandatory homing cycles after every machine power cycle.

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 3×400VAC from matched ACOPOS P3 drive; run 24-hour cyclic load test at 75% rated torque, logging EnDat position repeatability 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 encoder serial 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)

❗ Low-Voltage Drive Mismatch: This motor requires 400V-class ACOPOS drives; pairing with 230V low-voltage servo units creates insufficient torque output and consistent speed oscillation at full production load.❗ Shaft Seal Damage During Coupling Fit: Hammer strikes to the motor output shaft crack front IP65 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 EnDat encoder signal cables alongside high-current motor power wiring creates digital signal distortion, generating ±12 count position jitter during high-speed contouring cycles.❗ Unlocked Swivel Connector Housings: Loose angled connector bodies vibrate free under machine oscillation, breaking EnDat signal continuity and triggering uncontrolled axis coasting.❗ Unmitigated ESD Exposure: Low-humidity static discharges damage onboard EnDat encoder 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/encoder connector pinouts, coupling gap dimensions, and cable bend routing for exact replication.
2. Removal: Loosen coupling clamping fasteners; disconnect both circular swivel 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; lock swivel connector housings fully before cable strain relief mounting.
4. Power-on Test: Execute auto motor identification routine in Automation Studio; run low-speed jog cycles; verify stable absolute encoder position readings before full production speed operation.

FAQ (Frequently Asked Questions)

Q: Does the EnDat multi-turn encoder require a backup lithium battery for position tracking?A: No. This unit uses Wiegand energy harvesting for multi-turn position storage. No periodic battery replacement is needed, eliminating unplanned downtime from dead encoder cells.Q: Can this motor sustain continuous operation at peak 19.5Nm torque?A: No. Peak torque is limited to brief acceleration/deceleration duty cycles (<5% total runtime). Sustained torque above rated 6.5Nm exceeds Class F insulation thermal limits and accelerates winding degradation.Q: Which ACOPOS drive families fully support the 400V winding and EnDat absolute feedback?A: ACOPOS P3 8EI40-series and ACOPOSmulti 8BVI40-series high-voltage servo drives. Older 230V low-voltage drive variants lack native 400V winding parameter sets.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 +40°C cabinet ambient; at max +60°C operating temperature, continuous rated output falls to 76% of nominal 6.5Nm torque.Q: Are generic third-party circular motor cables compatible with the swivel connectors?A: Physically compatible, but uncertified cables lack full EMC twisted shielding. Field data shows 4.1x higher EnDat communication 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, encoder, and bearing manufacturing defects; damage from coupling impact, coolant ingress, or unshielded wiring-induced signal failure is fully excluded from coverage.