Purchase now: Bonfiglioli BN 71B 6 AC Electric Motor
Purchase now: Atlantechdrives provides you the BN 71B 6 230/400-50 IP55, an exceptionally reliable and robust three-phase asynchronous AC induction motor manufactured by the global power transmission leaders at Bonfiglioli. Designed to comply strictly with IEC international standards, the BN series is universally recognized for its durability in severe industrial applications. This specific model is built on an IEC 71B aluminum frame and features a specialized 6-pole stator winding. Operating at a standard 50Hz frequency, it delivers a synchronous speed of 1000 RPM (typically running around 900-940 RPM under nominal full load). This lower base speed makes it the ideal prime mover for applications requiring higher intrinsic torque without relying entirely on a massive reduction gearbox, such as heavy-duty agitators, slow-moving conveyor belts, and specialized industrial mixers. Enclosed in a highly durable, thermally optimized housing with an IP55 protection rating, it effectively repels factory dust and low-pressure water jets, ensuring maximum uptime.
Technical Specifications of the BN 71B 6 Motor
This motor utilizes premium-grade copper windings and high-quality Class F insulation, ensuring it can withstand significant internal heat generation without electrical breakdown. The dynamically balanced rotor guarantees silent, vibration-free 24/7 operation.
- Part Number: BN 71B 6 230/400-50 IP55
- Motor Type: 3-Phase AC Induction Motor
- Frame Size: IEC 71B (Aluminum construction)
- Number of Poles: 6-Pole (1000 RPM synchronous speed at 50Hz)
- Voltage Requirement: 230V Delta (Δ) / 400V Star (Y)
- Frequency: 50 Hz
- Protection Rating: IP55 (Dust-tight and water jet protected)
- Cooling Method: IC411 (Totally Enclosed Fan Cooled – TEFC)
Expert Installation Advice: 6-Pole Dynamics and Wiring
Understanding the mechanical output of your motor is critical. Expert Tip: Standard industrial motors are typically 4-pole (1500 RPM). Because this is a 6-pole motor (1000 RPM), it provides significantly more torque for the same horsepower rating. When integrating this motor with a gearbox, you must recalculate your final output speed based on this lower 900 RPM base, not the standard 1400 RPM base. Furthermore, the nameplate explicitly states «230/400V». If your factory provides a standard 400V 3-phase power supply, you must arrange the brass terminal links inside the junction box into the «Star» (Y) configuration to safely distribute the voltage. Incorrectly wiring this motor in Delta (Δ) at 400V will melt the copper insulation within seconds.
Maintenance and VFD Compatibility
The BN 71B 6 features robust Class F insulation, making it highly suitable for operation with Variable Frequency Drives (VFDs). However, because it is a TEFC (Totally Enclosed Fan Cooled) motor, the rear plastic fan is directly attached to the rotor shaft. If you use a VFD to run this 6-pole motor at exceptionally low speeds (below 20 Hz), the fan will not push enough air over the cooling fins to dissipate the heat generated by the copper losses. For continuous low-speed operation, consider adding an external forced-ventilation unit to prevent thermal tripping.
Frequently Asked Questions (FAQs)
Q: Can I run this 50Hz motor on a 60Hz power grid?
A: Yes. Most Bonfiglioli 50Hz motors can safely operate on a 60Hz grid. However, the synchronous speed will increase by 20% (up to 1200 RPM), and you must adjust your driven machine’s gearing to compensate for the higher output speed.
Q: Does an IP55 rating mean the motor is waterproof?
A: No. IP55 means it is highly protected against dust ingress and low-pressure water jets from any direction (like a factory washdown). It cannot be fully submerged in water.
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