GB/T 14711-2025 “General Safety Requirements for Small and Medium-sized Rotating Electrical Machines” was released on May 30, 2025, and will come into effect on December 1. This standard replaces GB/T 14711—2013 “General Safety Requirements for Small and Medium-sized Rotating Electrical Machines”. Compared with the 2013 version, it has undergone significant adjustments in multiple core technical dimensions, making it more suitable for the current development of motor technology and safety assurance needs.
This standard has removed the clause that “for small power motors produced in accordance with GB/T 5171, GB/T 12350 can also be used as the assessment basis”, and at the same time, has added relevant marking and description requirements for motor service factor, variable frequency speed control motors, etc., making the assessment standards for motors more unified and the key parameter identification clearer.
In terms of wiring and grounding, it has supplemented the requirements for wiring boxes and wiring devices of various special motors such as AC/DC dual-purpose motors and AC motors above 750V. It has also added a method for measuring the grounding resistance of small power motors, solving the problem of the absence of test current stipulations in the previous version.
In terms of wiring and materials, it adjusted the internal wiring provisions, clarified the minimum cross-sectional area and rated voltage requirements for motor leads, changed the temperature limits for supporting energized components and insulating bushings, and added the “200 (N)” thermal classification to accommodate the application of new materials.
In terms of electrical insulation and structure, this standard has improved the performance indicators, test methods and sample requirements for the motor’s resistance to high-frequency pulses. It has also added requirements for the identification tests of type I and type II insulation structures. Type I needs to pass the partial discharge test, while type II must meet the impulse voltage level and must indicate the IVIC insulation grade. This significantly enhances the reliability of the insulation system.
In terms of the test requirements, not only new assessment rules for motors with brake coils and variable frequency speed control motors in the heat generation test have been added, but also several parameters such as the DC voltage range for insulation resistance measurement, the tripping current value of the overcurrent relay in the high-voltage transformer in the power frequency withstand voltage test, and the relevant assessment values for the static pressure test of the power supply soft cable clamping device have been adjusted. At the same time, the assessment values for the static pressure test of the power supply soft cable clamping device have been modified to make the test more in line with actual safety requirements.
In addition, the standard adds new clauses regarding the overall structure of the integrated motor drive system for drive and control, which need to comply with the relevant requirements of GB/T 4208. It also supplements the constant humidity and heat test method and clearly stipulates that after the humidity and heat test, contact current measurement and safety confirmation assessment need to be carried out. This is to adapt to the development trend of motor integration and enhance the safety performance of the motor in special environments.
Post time: Nov-29-2025