GB/T 22764 consists of the following parts, under the general title:
— Part 1: Generic Specification;
— Part 2: Series of Dimensions;
— Part 3: Environment and Climate;
— Part 4: Electrical Safety Requirements;
— Part 5: Basic Test Methods.
This part is Part 4 of GB/T 22764. This part shall be used in conjunction with other parts.
Cabinets for Low-voltage Switchgear — Part 4: Electrical Safety Requirements
1 Scope
This part specifies the design, requirements, electrical continuity of the protective circuit and degrees of protection provided by enclosure (IP code) of cabinets for low-voltage switchgear.
This part is applicable to cabinet products for low-voltage switchgear (hereinafter referred to as “products”).
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this part of GB/T 22764. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB 7251.1 Low-voltage Switchgear and Controlgear Assemblies — Part 1: Type-tested and Partially Type-tested Assemblies (GB 7251.1-2005, idt IEC 60439-1:1999)
GB 4208 Degrees of Protection Provided by Enclosure (IP Code) (GB 4208-2008, IEC 60529:2001, IDT)
3 Design
3.1 General
Electrical safety is designed primarily to protect against two types of hazards:
— electric shock.
— possible burns, fires and other harmful effects due to excessive temperature.
Therefore, the basic principle of safety protection is electric shock protection and thermal effect protection. Electric shock protection can be applied to the whole product, but also can be applied to a part of the product or a device.
Foreword II
1 Scope
2 Normative References
3 Design
4 Requirements
5 Electrical Continuity of Protective Circuit
6 Degrees of Protection Provided by Enclosure (IP code)
