scope:

The contents of this Handbook apply to all EBI Track 200 audio frequency track circuits. The more general requirements can be found in NR/L2/SIG/11752. Safety issues specific to EBI Track 200 applications are included directly or through reference to the generic EBI Track 200 documentation; general safety issues are contained in NR/L2/SIG/11752 and other relevant Network Rail standards.

The information provided in this Specification, either directly or through reference to the generic EBI Track 200 documentation, applies under normal levels of traction current only. It does not apply to fault currents. Traction current conditions shall be as specified in NR/L2/SIG/11752.

Purpose

This Handbook mandates Network Rail best practice in respect of EBI Track 200 audio frequency track circuit, previously known as TI21. In order to achieve the requirements of NR/L2/SIG/11752