scope:

The scope of this document covers requirements related to Network Rail 750 V rated d.c. controlled switchgear devices suitable for use in d.c. traction systems. Where this document references 750 V equipment, the requirements are equally applicable to lower voltage d.c. traction systems, including those operating at 630 V or 660 V.

These specific requirements, in addition to the general requirements of BS EN 50123, cover the following equipment types used by Network Rail as part of their 750 V d.c. distribution switchgear:

a) Circuit breakers;

b) Switches and disconnectors; and,

c) Short circuit switches and disconnectors.

The scope of this document specifically excludes depot short circuiting devices. The specification follows the requirements identified within the applicable British Standard, BS EN 50123-1:2003 Railway applications - Fixed installations - D.C. switchgear.

Section 5 provides the switchgear specific requirements using the lists of requirements given in the relevant part of BS EN 50123, including any Network Rail specific requirements where they fall within these lists.

Additional Network Rail specific requirements that fall outside the normative standards are outlined in subsequent sections.

Purpose

The purpose of this document is to define the specific requirements for Network Rail's 750 V d.c. switchgear, in accordance with the framework provided by the applicable British Standard BS EN 50123 parts 1 - 4, 6, 7 Railway applications - Fixed installations - D.C. Switchgear.

It will mitigate the risks of:

Unclear requirements leading to difficulties in procuring switchgear components

Increased costs from different Routes and projects working to different sets of requirements

Non-compliance of procured components to BS EN 50123.