GB 7251.5-2008 Low-voltage switchgear and controlgear assemblies - Part 5:Particular requirements for assemblies for power distribution in public networks
Substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs) for power distribution in public networks shall comply with all the requirements of GB 7251.1-2005 and shall also comply with the particular requirements contained in this part.
This part gives supplementary requirements for substation cable distribution boards (SCDBs) and cable distribution cabinets (CDCs), which are stationary, type-tested assemblies (TTA).They are used for the distribution of electrical energy in three-phase systems. Open-type ASSEMBLY are not covered by this part.
Individual components, such as fuses and switching devices that comply with other standards, shall also comply with the supplementary requirements of this standard.
The object of this standard is to state the definitions and to specify the service conditions, construction requirements, technical performances and tests for SCDBs and CDCs.
Higher performance and test levels may be required for particular networks, for example, those with meshed connections.
NOTE 1: If a CDC is equipped with additional equipment (for example meters), in such a way that the main function is changed considerably, then other standards may also apply as agreed between user and manufacturer (see 7.6).
NOTE 2: Where local regulations and practices permit, an SCDB or CDC according to this standard may be used in other than public networks.
SCDBs are suitable for installation in places where only skilled persons have access for their use; however, outdoor types may be installed in situations which may be accessible to the public.
SCDBs are connected to the low voltage terminals of distribution transformers by means of connecting bars, rods or cables.
CDCs are for outdoor installation in places which are accessible to the public, and where only skilled persons have access for their use.
