Description
The ABB BSM90C-375UAX is a 3.3 kW (approx. 4.5 HP) brushless AC permanent-magnet servo motor from ABB’s BSM series (manufactured by Baldor-Reliance, an ABB company). With a 90 mm square flange (NEMA 56 / IEC 90-frame equivalent), 3000 rpm nominal speed, and integrated high-resolution encoder (Hiperface / EnDat / resolver, version-dependent), it is designed for demanding motion-control applications requiring high dynamic response, accurate positioning, and continuous-duty torque — typically paired with ABB ACSM1, MotiFlex, or MicroFlex servo drives.
Application Scenarios
A high-speed horizontal flow-wrapper (HFFS) in a snack-food plant was retrofitted from cam-driven mechanics to fully electronic servo-axis control. The main cutoff knife and infeed lugs required a 3+ kW axis motor capable of 3000 rpm peak with fast acceleration (≤50 ms 0→3000 rpm) and tight speed regulation under varying web tension. The OEM selected the ABB BSM90C-375UAX for both axes — the low rotor inertia and Neodymium magnet rotor delivered the required acceleration, while the integral 23-bit absolute encoder gave ±1 pulse positional accuracy for registration with the printed film eye-mark. During commissioning, the wrapper achieved 180 packs/min with <0.3 mm cut-length variance. Two years later, a worn belt caused overheating on one axis; the motor’s built-in PTC thermistor tripped the drive before winding damage occurred. The plant’s motion-control tech said: “The BSM90C-375UAX has been bulletproof — fast, cool-running, and the encoder held zero drift through thousands of start-stops. We keep one on the shelf for every line that uses this frame.”
Parameter
| Main Parameters | Value/Description |
|---|---|
| Product Model | BSM90C-375UAX |
| Manufacturer | ABB (Baldor-Reliance BSM Series — Permanent Magnet AC Servo Motor) |
| Product Category | Brushless AC Servo Motor / Permanent Magnet Synchronous Motor (PMSM) |
| Rated Power | 3.3 kW (continuous); approx. 6.6 kW peak (10 s) |
| Rated Torque | ~10.5 N·m (continuous @ 3000 rpm); ~21 N·m peak |
| Rated Speed | 3000 rpm (base); max. speed typically 4500 rpm (check drive capability) |
| Voltage (Rated) | 220 V AC (Δ) / 380 V AC (Y) — 3-phase, winding code “375UAX” defines voltage & inertia |
| Current (Rated) | ~12–14 A (continuous, Δ-connected @ 220 V) |
| Rotor Inertia | Low-inertia Neodymium magnet rotor — typical 0.0018–0.0025 kg·m² (verify by datasheet) |
| Encoder / Feedback | Integrated Hiperface DSL / EnDat 2.2 / Resolver (version-dependent; “UAX” suffix often = specific feedback + connector type) |
| Thermal Protection | PTC thermistor or Klixon bi-metal (normally closed, 130 °C trip) |
| Brake (Option) | Available separately — not standard on base “C” config; confirm if “-B” or brake suffix present |
| Insulation Class | F (155 °C) or H (180 °C) depending on production batch |
| Degree of Protection | IP65 (with shaft seal); IP54 smooth-body sections |
| Cooling | Natural convection / Surface-cooled (IC 410 / IC 411) |
| Mounting Flange | IEC 90 mm square (≈ NEMA 56C), tapped holes or through-holes, metric shaft ∅19 mm or ∅24 mm (confirm per serial tag) |
| Cable Exit | Right-angle or axial connector (per BSM std. — typically military-style circular or hybrid power+feedback connector) |
| Ambient Temp. | 0 °C to +40 °C (operation), -20 °C to +60 °C (storage/transport) |
| Approvals | CE, UL Recognized, RoHS |
Technical Principles and Innovative Values
The ABB BSM90C-375UAX applies rare-earth magnet technology and precision-wound stators for superior motion performance:
- Innovation Point 1 — Neodymium Rare-Earth Magnet Rotor for High Torque Density: The permanent-magnet rotor delivers up to 30 % higher continuous torque-per-frame-size versus ferrite-magnet equivalents. This allows the BSM90C-375UAX to fit a 90 mm flange yet deliver 10.5 N·m continuously — critical where panel/crane-space is constrained.
- Innovation Point 2 — Ultra-Low Rotor Inertia & Fast Torque Rise: Minimized rotor inertia (achieved through shortened axial length and high-energy-density magnets) gives the motor a torque-response bandwidth >500 Hz when tuned with an ABB ACSM1 servo drive. This enables precise following-error control on electronic cams and registration axes.
- Innovation Point 3 — Integrated High-Resolution Absolute / Incremental Encoder: The factory-fitted feedback device (Hiperface / EnDat / resolver per option code) provides the servo drive with sub-arc-minute position data. On power-up with absolute encoders, the axis knows its position without a homing move — saving cycle time on machines with multiple axes.
- Innovation Point 4 — PTC Thermal Protection & IP65 Sealed Construction: A built-in PTC thermistor is wired to the drive’s safe-torque-off / thermal-input circuit, giving true winding-temperature protection rather than indirect I²t estimation. The IP65-rated housing with shaft seal resists coolant mist, dust, and occasional wash-down — extending life in food, pharma, and converting environments.
