scope:

This instruction applies to those Network Rail switches which are configured to act as concentrators and are primarily installed to support Network Rail's operational requirements such as Signal Boxes and Electrical Control Room applications.

Electronic PABX switches which are installed to meet a business need, such as offices and ICCs are to be maintained as detailed in NR/WI/TEL/30122 Maintenance of Electronic PABX Business Switches.

The switch installation may, by design, be constructed from a number of remote nodes or shelves. These shall be considered as separate switches and subject to the applicable procedures in the relevant appendix.

The maintenance requirements for the Power Plant and Batteries used to support Electronic PABX switches is detailed in NR/L2/TEL/30081.

The maintenance requirement for Keltek Timeslot Sharing Units (TSSUs) used to support circuits is detailed in NR/L2/TEL30076 Appendix D Service B. The maintenance requirements for Voice Recorders are detailed in NR/L2/TEL/30082.

Purpose

This instruction defines the maintenance requirements for Electronic PABX concentrators used by Network Rail.

The purpose of maintaining and testing operational concentrators is to decrease the incidence of failures through deterioration and to identify potential failures before they become service affecting.