VRIOGS 010.7 RevA - Public Transport Victoria

VRIOGS 010.7 Revision A 194. Where the length of the single-rail track circuit region exceeds 200 m, crossbondsmust be placed at either end; provided that no more than one end ofany double-rail track circuit is cross-bonded.5. Single rail track circuits shall be limited to areas covered by points andcrossings.6.4.3 Single Rail Impulse Track Circuits1. Single rail impulse track circuits provide a similar restriction to the tractioncurrent return path as for single rail AC track circuits.2. Cross bonds shall be provided at intervals not exceeding 250 m.3. Single rail track circuits shall be limited to areas covered by points andcrossings.6.4.4 Double Rail Impulse Track Circuits1. On double rail impulse track circuits the cross bonding shall be made atintervals of between 800 m - 1600 m, with 800 m being the optimum distanceand with one clear track circuit between the “tie-in” bonds.6.4.5 Jointless Track Circuits1. Cross bonds shall be provided at 800 m – 1600 m intervals with 800 m beingthe optimum and rated according to the traction current rating of the section.Jointless track circuits require an impedance bond to be providedapproximately at the middle of the track circuit for cross bonding connections.2. The actual cross bonding is connected between the neutral points ofimpedance bonds installed on parallel tracks. Impedance bonds used for“tying-in” shall be rated for the traction rating of the area where they areinstalled.3. The air core inductor in the tuned loop on CSEE track circuits shall not underany circumstances be used for “tying-in”, connection of spark gaps orelectrolysis connection points.6.4.6 Tying-in Non-Track Circuited Tracks1. Where tracks are wired for electric traction but not track circuited, both railsshould be bonded directly together and tied in to the traction return system attheir extremities and at intermediate points, depending on the length of thetrack involved.2. Non-track circuited electrified track shall be cross bonded to track circuitedelectrified track at locations appropriate to the types of track circuit installed.3. Bonding shall be installed in accordance to Plan STD_G0097 Suburban AreaCross Bonding Typical Arrangement.NOTE: 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.