Technical Description: Bonfiglioli BN 71B 4 AC Motor
The Bonfiglioli BN 71B 4 is a high-quality three-phase asynchronous AC motor designed for general industrial use. Part of the BN series, this motor is a benchmark for reliability and efficiency in standard power transmission. It is engineered to meet the international electrical standards (IEC), making it compatible with a vast range of gearboxes and machinery worldwide.
Core Performance Characteristics
This motor features a 4-pole design, providing a nominal speed of approximately 1400-1450 RPM at a frequency of 50Hz. Rated for 230/400V (Delta/Star connection), it is versatile enough for various industrial power grids. The IP55 protection rating ensures that the motor is protected against dust ingress and low-pressure water jets, making it suitable for standard factory environments.
Key Specifications
- Frame Size: 71B
- Number of Poles: 4
- Voltage: 230/400V AC
- Frequency: 50 Hz
- Protection Class: IP55
- Insulation Class: F (155°C)
- Duty Cycle: S1 (Continuous duty)
- Housing Material: Die-cast Aluminum
Industrial Reliability and Safety
The BN 71B 4 motor is built with high-quality copper windings and precision-balanced rotors to minimize vibration and noise. Its aluminum frame offers excellent thermal conductivity, ensuring the motor stays within safe operating temperatures even during continuous 24/7 operation. It is the perfect pairing for Bonfiglioli VF, W, and A series gearboxes.
| Parameter | Value |
| Rated Power | 0.37 kW (0.5 HP) |
| Mounting Options | B5, B14, or B3 (Ref. specific flange) |
| Efficiency Class | Standard Efficiency |
Maintenance Insights
The motor features permanently lubricated ball bearings, which reduces the need for periodic maintenance. For long-term reliability, ensure that the fan cover remains unobstructed to allow for optimal airflow across the cooling fins.
For applications requiring a lower output in the same IEC 71 frame, the Bonfiglioli BN 71A 4 230/400-50 IP55 offers a compact alternative with identical mounting dimensions.
Do you need more references from this brand? Explore our full catalog of Bonfiglioli here.
