GB/T 3906-2020 Active

This standard specifies the technical requirements for AC metal-enclosed switchgear and controlgear with a rated voltage of 3.6 kV to 40.5 kV, including terminology and definitions, operating conditions, rated values, design and structure, type testing, factory testing, and other aspects.
This standard applies to factory-assembled AC metal-enclosed switchgear and controlgear with a rated voltage of 3.6 kV to 40.5 kV, installed indoors or outdoors, and operating at a frequency of 50 Hz or lower. The enclosures of these devices may contain fixed or removable components and may be filled with insulating and/or disconnecting fluids (liquids or gases).
Note 1: This standard primarily targets three-phase systems, but it can also be used for single-phase or two-phase systems.
Based on the following factors, this standard classifies metal-enclosed switchgear and controlgear into several categories:
—— The continuity of grid operation during the maintenance of switchgear and controlgear;
—— The need and convenience of equipment maintenance.
Note 2: The safety of the equipment depends on the design, manufacturing, use, adjustment, coordination, installation, and operation of the product.
For metal-enclosed switchgear and controlgear with inflatable compartments, this standard applies when the design pressure does not exceed 0.3 MPa (relative pressure).
Note 3: Inflatable compartments with a design pressure exceeding 0.3 MPa (relative pressure) should be designed and tested in accordance with GB/T 7674.
Metal-enclosed switchgear and controlgear for special purposes, such as in areas with flammable gases, in mines, or on ships, may require additional technical requirements.
The various components installed in metal-enclosed switchgear and controlgear are designed and tested in accordance with the respective standards. Considering the installation situation of each component in the complete switchgear and controlgear, t