VRIOGS 010.7 RevA - Public Transport Victoria

12 VRIOGS 010.7 Revision ASECTION 6.0ELECTRIFIED TRACK AREAS6.1 GeneralAny traction current supply infrastructure installed on electrified track where electrictrains are intended to run shall be designed and maintained to the standards of theelectrical supply infrastructure owner for the benefit of whom the equipment isinstalled.The calculation of traction return resistance is the responsibility of the TractionSystem Engineer; however, the Signal Engineer should be aware that the followingguidelines exist.Number of electrifiedtracksOne trackTwo tracksMultiple tracksNumber of rails required for traction current return2 rails at all times (with exception over points and crossinglayouts)4 rails except for short distances, within interlockings, overpoints where 3 may be acceptableMaintain the ratio for dual track unless specific permission isobtained from the Infrastructure Manager.Table 1 Rails required for traction return currentLong single-rail track circuits should not be used in electrified areas.Where the use of single rail track circuits over long distances is unavoidable the casemust be referred to the Infrastructure Manager for specific approval, as highertraction return resistances adversely affect DC traction current Circuit Breaker(DCCB) settings.6.2 Traction Supply InterfacesThe traction return current rails shall be interfaced with the Traction System NegativeBus bars at each Substation and Tie Station.6.2.1 Substations1. At each substation the connection from the negative busbar to each trackused for traction current return shall be duplicated.2. Cables carrying the traction return current to the negative busbar shall bespecified to carry the full rated traction load i.e. 2000 A per rail.3. Where there is more than one track used for traction current return, they shallbe tied together except where the traction system has provided a separatenegative busbar for each track.4. Where single rail track circuited or non-track circuited track is in use thetraction current return rails shall be bonded directly to the negative bus bar. ItNOTE: This document is controlled only when viewed on the DOT Engineering Standards website.Any other copy of this document is uncontrolled, and the content may not be current.