BS EN 50532:2010

This European Standard specifies the service conditions, rated characteristics, general structural requirements and test methods of the prefabricated assembly of the main electrical functional units of a HV/LV Distribution Substation, duly interconnected, for alternating current of rated operating voltages above 1 kV and up to and including 52 kV on the HV side, service frequency 50 Hz. This assembly is to be cable-connected to the network.

This Compact Equipment Assembly for Distribution Substation (CEADS) as defined in this standard is designed and tested to be a single product with a single serial number and one set of documentation. Such equipment is delivered as single transport unit. For practical reasons manufacturer and user can agree to transport the unit dismantled if transport or installation of the complete CEADS is not possible. In that case suitable verification tests shall be carried out at the installation site.

Note 1: Where the functional units are independent each functional unit will also have its own serial number.

A CEADS is not a Distribution Substation, either prefabricated (covered by EN 62271-202) or not (covered by EN 61936-1). However CEADS is intended to become part of a Distribution Substation assembling the HV equipment, the power transformer and the LV equipment duly interconnected (see Annex C, which also explains the origin and types of CEADS).

The functions of a CEADS are:

• switching and control for the operation of the HV side and protection of the HV/LV transformer functional unit;

• HV/LV transformation;

• switching and control for the operation and protection of the LV feeders.

However relevant provisions of this standard are also applicable to designs where not all of these functions exist (e.g. equipment comprising only HV/LV transformation and switching and control for the operation and protection of the LV feeder functions).

For public distribution networks, CEADS are intended for installation within an indoor or outdoor closed electrical operating area (see Definition 1.3.3) forming part of a Distribution Substation.

For industrial applications, such as factories, installation of CEADS outside a closed electrical operating area may be allowed provided that safety regulations are fulfilled by additional measures adopted at the installation site under the responsibility of the designer of the installation.

This standard considers the potential interaction between the individual functions when closely installed and interconnected to form a type tested assembly and defines ratings, particular design and construction requirements and test procedures for this assembly.

NOTE 2 Interaction is the influence of one functional units of the equipment on another (i.e. electrical mechanical and thermal stresses).

NOTE 3 For the purpose of this standard a self-protected transformer is considered not as a CEADS, but as a functional unit, designed and type tested to its own product standard EN 60076-13.