Bonfiglioli BN-BE-BX Series Motor Selection Guide

Bonfiglioli BN-BE-BX Series Three phase Asynchronous Motor: Selection, Configuration, and Braking System

In the field of industrial transmission, the selection of three-phase asynchronous motors as the core power execution components directly determines the efficiency and reliability of the entire production line. Bonfiglioli's BN, BE, BX series motors cover all efficiency levels from IE1 to IE4, providing a wide range of power options for general industrial applications such as pumps, fans, compressors, and material conveying. However, faced with a multitude of machine base numbers, pole numbers, voltage combinations, and braking options, engineers often need to make a large number of detailed decisions during the selection stage. This article will be based on the technical documents of the BN-BE-BX-BY series, and provide you with a complete selection approach from understanding energy efficiency standards to implementing specific models.

Evolution of Energy Efficiency Grades and Interpretation of Standards

To understand the essential differences between the BN, BE, and BX series, it is first necessary to clarify the evolution of global motor energy efficiency standards.

1. Definition from IE1 to IE4

The International Electrotechnical Commission (IEC) defines the International Energy Efficiency (IE) rating for motors through the standard IEC 60034-30-1:2014. The manual clearly lists the level codes on pages 5-6:

IE1 (Standard Efficiency): Standard Energy Efficiency, corresponding to the BN series

IE2 (High Efficiency): High efficiency, corresponding to the BE series (and compact ME series)

IE3 (Premium Efficiency): Ultra high energy efficiency, corresponding to BX series (as well as compact MX series)

IE4 (Super Premium Efficiency): Ultra premium energy efficiency, covering some specific models

This grading system has been adopted by the EU ERP Directive (2009/125/EC) and EU Regulation 2019/1781. Starting from July 2023, the European market has mandated that motors within a specific power range must have an energy efficiency rating not lower than IE3. Therefore, when choosing motors, if the target market is Europe, choosing BX (IE3) or higher directly is a wise move to avoid compliance risks.

2. Special considerations for frequency converter power supply

For variable frequency drive (VSD) applications, traditional IE rating standards are not fully applicable. On page 6 of the manual, it is stated that IEC TS 60034-30-2:2016 specifically defines the energy efficiency level (IE code) for variable frequency motors. In addition, the IEC 61800-9 standard introduces the Extended Product Approach to evaluate the energy efficiency (IES level) of the entire system consisting of a frequency converter, motor, and load. This means that if the motor needs to operate in variable frequency mode for a long time, in addition to focusing on the efficiency of the motor itself, it is also necessary to comprehensively consider the loss matching of the driver.

Decoding Motor Naming Rules: Understanding Configuration from Model

Bonfiglioli's motor models follow a rigorous coding logic (pages 9-11 of the manual). Understanding this encoding is the first step in precise selection.

Taking model BX 132SB 4 230/400-50 IP55 CLF B5 W FD 7.5 R AA SB as an example:

Series code: BX represents IE3 efficiency level; BE is IE2; BN is IE1.

Machine base number and iron core length: 132SB represents a machine base height of 132mm, and SB is the code for iron core length (different lengths correspond to different powers). The correlation table (F64) on page 54 of the manual lists the correspondence between the machine base and power, for example, the rated power of BX 132SB 4 at 50Hz is 5.5kW.

Pole number: 4 represents a 4-pole motor (synchronous speed of approximately 1500rpm @ 50Hz). The BN/BE/BX series covers 2, 4, and 6 poles (some have 8 poles), and the different number of poles determines the speed torque characteristics of the motor.

Voltage and Frequency: 230/400-50 represents a voltage of 230V △/400VY and a frequency of 50Hz. Pages 20-21 of the manual provide detailed voltage combinations for different certification versions, such as CUS (North American Certification) version which is typically 265/460-60Hz.

Protection level and insulation level: IP55 is standard protection, CLF is F-level insulation (temperature rise limit of 105K). Optional CLH (H-class insulation) for higher temperature environments.

Installation method: B5 is flange installation (with flange); B3 is for horizontal foot installation; B14 is for small flange installation. On page 15 of the manual, it is stated that B3 can be combined with B5 or B14 to form B35 or B34.

Brake information: W represents the standard position of the junction box; FD stands for DC spring brake; 7.5 is the braking torque (Nm); R is the manual release lever (automatic reset); AA is the release lever orientation; SB is a rectifier type (overexcitation type).

Selection and Performance Parameters of FD Brake

The selection of brake motor is crucial for situations that require quick stopping or safe maintenance, such as lifting and hoisting equipment.