VRIOGS 010.7 RevA - Public Transport Victoria

24 VRIOGS 010.7 Revision Aspark gap device connection point on the overhead structure. The Constructorshall then provide the spark gap device and install the cable to connect fromthe spark gap to the rail, which shall be connected to the traction return rail tothe satisfaction of the Signal Engineer.3. An approved crimp lug shall be fitted to the spark gap cable and connection ofthe cable made to the rail and also to the spark gap.4. Where overhead structures are installed or relocated, the Constructor shallsupply and install a spark gap and cable for each structure. Each spark gapshall be connected to the traction return rail by a 95 mm 2 aluminium singlecore cable in accordance with VRIOGS Signalling Cable Specification.5. Spark gap cables and connections are only to be made to the traction returnrail. The spark gap cable shall be laid on ballast level to the verge of the trackformation; and then installed in either rigid orange PVC electrical conduit orheavy duty flexible orange PVC electrical tube, and buried at a minimumdepth of 300mm to the connection point at the overhead structure. All cablesshall be fastened to sleepers as per within this specification6. On single rail track circuits the spark gap shall be connected to the tractionreturn rail.7. On double rail track circuits the spark gap shall be connected to the rail that isclosest to the actual overhead structure being protected by the fitment of thespark gap-except that when audio frequency track circuits are in use and theconnections of subsequent overhead structures must remain on the same rail,and change to the opposite rail at the middle of the track circuit.8. Spark gaps shall not be installed within the tuned loop area of a frequencytype track circuit.9. Connection to the rail shall be in accordance with this specification.10. Cable lugs shall be provided at both ends of the spark gap cable. Lugs shallbe bi-metallic or copper and comply with AS4325.1, e.g. CABAC PartNo. CAL95-12 or approved equivalent. Thick walled glue lined heat shrink(100 mm in length) shall be used to seal where the cable enters the lug.11. The spark gaps shall be supplied in accordance with the "Spark Gap EarthingDevice" Plan No. STD_G0070.12. Where train stabling security gates are in close proximity to steel structuressupporting overhead wiring, consideration must be given to the possiblerequirement for a spark gap protective device and in accordance with EN50122-1:1998 Railway Applications-Fixed Installations-Part 1:ProtectiveProvisions relating to Electrical Safety and Earthing.6.9 Impedance Bonds6.9.1 GeneralThe Constructor shall supply and install all necessary impedance bonds including thereplacement of any existing impedance bonds.1. Negative return traction cabling shall not be installed within the same conduitor cable route as other signal cabling and shall be separated from all othercabling in accordance with VRIOGS 012.2 Signal Supply Construct InstallSpecification.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.