scope:

This standard specifies the following:

a) The requirements for identification and colours to be adopted for the signalling power supply distribution cables in new installations; and

b) How to interface new colour identification system with old colour identification schemes when making alterations to old signalling power systems and assets.

NOTE Conductors cores identified in accordance with BS 7671:2001+A2:2004 (and subsequent versions) are referred to as 'new colours', and conductors identified to versions of BS 7671 prior to 2004 is referred to as 'old colours'.

This standard applies to all Network Rail staff and contractors designing or working on new signalling power installations or alterations to existing ones.

This standard does not cover cable colours and identification for d.c. distribution systems, e.g. battery supplies or uninterruptible power supplies etc., which should follow NR/L2/SIG/11201 and BS 376-2, or BS 7671, as appropriate.

Purpose

This standard specifies the cable identification requirements for signalling power supply distribution cables. This reduces the risk of cables being mis-identified during installation, isolations and incorrect connections leading to potential mal operation of signalling systems.