Chapter 21: Relay & Electronic Interlocking PDF

21.6.2 Specific tests for Electronic interlocking (a) Maintenance of Electronic Interlocking system shall be done as per approved system maintenance manuals. A general maintenance schedule for Electronic interlocking is provided for guidance at Annexure: 21-MS3 in...

21.6.2 Specific tests for Electronic interlocking (a) Maintenance of Electronic Interlocking system shall be done as per approved system maintenance manuals. A general maintenance schedule for Electronic interlocking is provided for guidance at Annexure: 21-MS3 in Appendix I. Note: At stations having dense traffic and high speed, the Railways may prescribe more frequent inspections, if considered necessary. (b) Maintenance Terminal of Electronic Interlocking system shall be provided in the Signal Technician Duty room. (c) Latest E.I station database files (application logic, Control Terminal database, etc.) shall be kept updated in centralized server as specified. (d) Periodic testing of redundant systems shall be carried out. Checksums shall be verified during periodic inspections. (e) Additional References for Electronic Interlocking. (i) Relevant International Standards (or equivalent standards) with latest revisions are also applicable to development and implementation of safety related railway signalling systems and projects including Electronic Interlocking. IEC stands for “International Electro technical Commission” and CENELEC stands for “European Committee for Electro technical Standardization”. (ii) RDSO Specifications and Technical Advisory Notes (TAN) with latest amendments are applicable for design, installation, testing and maintenance of Electronic System. Section 7: Lightning & Surge Protection for Signalling Equipments 21.7.1 Lightning-General: Lightning and surge protection shall be provided to protect Electrical & electronic signalling equipments from lightning & surges. (a) S&T equipment shall be protected as per National Building Code 2016 (NBC 2016) and IEC 62305. S&T equipment, including those given below, are to be grounded and protected from lightning surges. Code of Practices, Technical Advisory Notes, Guidelines issued by RDSO on the subject shall be taken into consideration. (i) Electronic Interlocking Installations including Object Controllers. (ii) BPAC Systems, Axle Counter Systems, Integrated Power Supply Systems. (b) Equi-potential bonding to be provided for all the equipment for effective lightning and surge protection in Signal Equipment Rooms. (c) External Lightning Protection and Class/Type I, II & III devices are to be provided at Chapter 21: Relay & Electronic Interlocking Page 462 of 530  (i) External Lightning Protection on Top of Buildings housing S&T equipment. (ii) Class B/Type-I devices at the Input of Power Supply Equipment. (iii) Class C/Type-II devices at Output of Power Supply Equipment. (iv) Class D/Type-III devices at Indoor and Field Equipment. 21.7.2 Earthing for Electronic Interlocking (a) Earthing shall be provided as per approved specifications, drawings and code of practice. (b) To the extent possible, perimeter earth shall be provided around the Electronic Interlocking room. (c) Earth value shall be less than one ohm and shall be measured annually during dry season. (d) Copper tape (Bonding ring conductor) as per drawing mounted on insulated stand-off is provided to cover the maximum area in the Relay room and the connection to equipment shall be made at the nearest point. (e) Earth wire from Surge protection device to main earth terminal inside the room should be as straight and short as possible to provide a low impedance path for discharge of surge energies. (f) Earthing wires from electronic interlocking subsystems to main earth terminal shall be of distinctive color. Green or Green Yellow (GNYE) color is recommended for quick identification of a loose or disconnected earth wire. (g) All earth wires shall be as straight as possible and shall never be coiled. All Earth wires should be made of copper of adequate current carrying capacity and should never be less than 4 Sq.mm cross section. Chapter 21: Relay & Electronic Interlocking Page 463 of 530