Chapter 16: Power Plant Systems For Telecom Installations - PDF

CHAPTER XVI POWER PLANT SYSTEMS FOR TELECOM INSTALLATIONS 16.1. GENERAL 16.1.1 This chapter discusses the power supply requirements for following Telecommunication Equipments: Train Radio System Public Address System...

CHAPTER XVI POWER PLANT SYSTEMS FOR TELECOM INSTALLATIONS 16.1. GENERAL 16.1.1 This chapter discusses the power supply requirements for following Telecommunication Equipments: Train Radio System Public Address System Network Server Centre Passenger Information Display System Optic Fibre Equipment Video Surveillance System (Close Circuit TeleVision) Multiplexing Equipment Centralised Clock System Telephone Exchanges Datacom Equipment of PRS, FOIS, UTS, SCADA etc. Train Traffic Control Equipment Voice Logging Equipment WiFi equipment Railnet, Video conference equipment 16.1.2 All Telecom Equipments shall be provided with a reliable Power Supply. 16.1.3 Telecom System/Equipments like Public Address System, Passenger Information Display System, Wifi equipment, Video Surveillance System (Close Circuit TeleVision), Centralised Clock System, Voice Logging Equipments, Railnet, Video conference equipment, Datacom Equipment of PRS, FOIS, UTS etc operates on 230 V AC Power Supply. 16.1.4 Telecom System/Equipments like Train Radio System, Optic Fibre Equipment, Multiplexing Equipments, Telephone Exchanges etc operates on 48 V DC Power Supply. 16.1.5 Train Traffic Control Equipment operates on 12/24/48 V DC. VOIP based TTC may work on standard AC power supply ( 230 V AC) too. Datacom Equipment of SCADA operates on 48/110 V DC or 230V AC. 16.1.6 If more than one type of system such as Radio Equipment, OFC system and Train Radio are housed in the same room or adjacent rooms of the same building, only a common power plant shall be used for all such systems. 16.1.7 Power supply in the network server centers are important as they are supposed to be working under all conditions. Network server centers normally host servers and few Telecom equipment. Hence, most reliable 230V AC shall be provisioned in the network server center. Here, the UPS system shall be provided with N+1 redundancy. For telecom equipment inside the network server center, the telecom charger may be connected with the output of UPS without its own 48 V battery backup arrangement. DG supply is also to be extended to the network server center. Indian Railways Telecom Manual - 2021 Page 206 16.2. SOURCE OF AC POWER SUPPLY: (a) In RE area, traction supply from both up and down catenary will be provided through AT Transformer with auto changeover arrangement at all wayside stations and other critical locations. Separate fuse/Circuit breaker arrangement to be provided for telecom equipment when common source of supply is used. (b) Local supply shall be single phase or 3 phase depending upon the load requirement. (c) Three independent sources of power supply should be arranged for all critical telecom installations. Diesel generator/Solar power back up shall be installed wherever local supply is unreliable and both AT supply ( up and down) are not provided. (d) PROVISION OF SOLAR BASED POWER SUPPLY SYSTEMS: Solar based power supply system can be planned where reliable power supply is not available and; (i) Clear and sunny weather is generally available throughout the year. (ii) Sufficient space free from shadow and any other obstruction is available for installation of the solar panels. (iii) Proper cleaning of dust particles, tree leaves or any other foreign material from the surface of solar panels is ensured. (iv) Adequate provision is made for storage of power for at least five continuous sunless days. (v) Anti theft arrangement shall be provided at all vulnerable locations. 16.3. DIESEL GENERATOR SUPPLY 16.3.1 Diesel Generator Capacity: The capacity of the generators shall be calculated based on the present load requirements plus the anticipated increase of load, if any, in the next five years period. Load requirements for all the equipment including aviation lights & emergency lighting of equipment room shall be included. Operation of the air conditioners at all critical telecom locations shall be done from dedicated/standalone diesel generators also only in exceptional circumstances on temporary basis. Normally it should be planned with all other sources of power supply available with Railways. 16.3.2 Installation of Diesel Generator Set : (a) Diesel Generators: Silent DG sets (with acoustic enclosure) only shall be used. It shall be equipped with an auto start/stop mechanism. The diesel generators shall be installed as per the manufacturer’s instructions. All Indian Railways Telecom Manual - 2021 Page 207  mountings shall be rugged, durable and sufficiently strong to withstand vibrations occurring in the area of the site. Anti-vibration cushion should be provided between the floor of the DG Room/shed and the DG set. Diesel Generator should be earthed as per manufacturer’s specifications. (b) Exhaust Gas: Exhaust gas shall be thrown outside the building through suitable exhaust pipes properly fitted & mounted. The exhaust pipes must be wrapped with heat insulation to protect staff from burn injury in case of accidental touch. All flexible pipe connections shall be screwed or flanged. A suitable silencer shall be fixed at the end of the exhaust pipe, if required. (c) Type of cooling: All diesel generators shall be air cooled type. (d) Fuel Tanks: The capacity of the tank shall be adequate to store fuels for at least 24 hours of operation at full load. (e) Wiring and Cabling: The cables and wires from the generators shall be drawn through rigid conduits or enclosed in proper channels. 16.3.3 Control System of Diesel Generator Sets: (a) The control system of the diesel generator sets shall broadly have following capabilities: (i) Detection of AC mains failure. (ii) Detection of deviation of the mains supply voltage and frequency beyond prescribed limits (230 V ± 5%, 50Hz±2Hz). (iii) Detection of overheating of engines. (iv) Detection of high/low output voltage and frequency from the generator. (v) Detection of restoration of AC mains supply. (vi) Detection of low lubricant oil pressure (vii) Detection of V belt failure. (viii) Hour meter: To monitor the total operative time of DG Set. (b) The control system shall generate alarm condition in case of fault conditions such as: - High engine temperature - Low oil pressure - Generator overload - Generator output voltage beyond limits. (c) Remote alarm monitoring / remote operating features should preferably be provided. In case of fault conditions, the control system shall shut down the diesel generator and lock it out of service until the same is manually reset by the maintenance personnel. (d) The control system shall incorporate manual controls to permit: Testing of generator sets. Indian Railways Telecom Manual - 2021 Page 208  Bypass the automatic control systems and connect the generator output to the load. 16.4 AC POWER SUPPLY DISTRIBUTION ARRANGEMENTS 16.4.1 Notwithstanding this Clause all existing installations shall continue with existing arrangement of AC Power Supply Distribution for Telecom Equipments. However new installation shall follow the guidelines stipulated herein. 16.4.2 Incoming AC Power Supply from AT Transformer (through Automatic Changeover), Local Power Supply, Diesel Generator Power Supply, Solar Panel Power Supply shall be terminated in an AC Distribution Board. 16.4.3 This AC Distribution Board shall have facility of changeover from one incoming source to other. 16.4.4 Incoming AC Power Supply on AC Distribution Board shall be terminated through MCCBs & MCBs of adequate capacity. 16.4.5 Outgoing Single Phase AC Power Supply for individual Telecom Equipment from AC Distribution Board shall be through MCBs of adequate capacity. 16.4.6 Integrated Surge & Transient Protection Devices shall be provided in AC Distribution Rack for sensitive Telecom Equipments. Surge & Transient Protection shall be as per guidelines/specifications issued by RDSO. 16.4.7 AC Distribution Board shall have sufficient spare capacity to accommodate anticipated future expansion. AC Distribution Board can be “wall mounted metallic enclosure” or “floor mounted cubicle”. 16.5 DC POWER PLANT SYSTEM 16.5.1 Battery Chargers and Voltage Stabilizers: All Telecom installations shall be provided with float cum boost charger of adequate capacity in N+1 or N+2 as per latest RDSO specification. Charger Capacity should be minimum C/10 + load where C is the AH of the battery. Single Phase 48 V DC Power Plant are categorized as below depending upon Stability of Incoming Power Source; (i) Suitable for incoming power supply range from 165 V AC to 260 V AC. (ii) Suitable for incoming power supply range from 90 V AC to 300 V AC. 16.5.2 Number of Battery Banks & Mode of Operation: One set of battery on float mode working should normally be planned. At stations prone to lightning, two sets of battery banks shall be planned either with manning or with charger having feature to work automatically in charge-discharge mode of operation. 16.5.3 Type and Capacity of Battery: In a controlled environment where temperature is not very high or where batteries can be accommodated in temperature controlled equipment room area, VRLA batteries can be used. Where temperature is normally on the higher side, low maintenance secondary cells Indian Railways Telecom Manual - 2021 Page 209  should be provided. The batteries shall be of adequate capacities to deliver the full load for a period of at least 12 hours duration throughout its useful life, considering future requirement. 16.5.4 Load requirement: The load requirement shall be calculated based on the present load plus the anticipated increase of the load, if any, in the next five years period. 16.5.5 SMPS Based Telecom Integrated Power Supply: It is used in Auto Float Rectifier-cum Float-charger (FR-FC) and/or Float Rectifier cum Boost Charger (FR-BC) mode as a regulated DC power source; DC-DC Converters are for various DC power supply requirements of Telecom equipment at Railway Stations such as 25W VHF Set, VF Repeater, Gate Telephone, Way Station Control Telephone, Magneto Telephone, STM1/4 OFC Equipment, PD MUX, Router, Switches etc. 16.6 DC POWER SUPPLY DISTRIBUTION ARRANGEMENT 16.6.1 Incoming DC Power Supply shall be terminated in a DC Distribution Board. DC Distribution Board can be “wall mounted metallic enclosure” or “floor mounted cubicle”. 16.6.2 Incoming DC Power Supply on DC Distribution Board shall be terminated through DC MCB of adequate capacity. 16.6.3 Outgoing DC Power Supply for individual Telecom Equipment from DC Distribution Board shall be through DC MCBs of adequate capacity. 16.6.4 DC Distribution Board shall have sufficient spare capacity to accommodate anticipated future expansion. 16.7 REQUIREMENT OF POWER SUPPLY ROOM(S): 16.7.1 Wherever secondary batteries are used, the stabilisers, chargers, distribution boards and the changeover switches shall be installed in a separate room adjacent to the battery room. 16.7.2 Wherever VRLA batteries are used, the stabilizers, chargers, distribution boards and the changeover switches may be kept in the same room as VRLA Batteries. 16.7.3 Power Supply Room(s) shall be dry, cool, well lighted and well ventilated. Exhaust fans shall be provided to remove fumes in all Power Supply Rooms where secondary batteries are installed. 16.7.4 It is desirable that the window glasses shall be frosted or painted wherever necessary to prevent direct sun rays falling on the cells. 16.7.5 The Power Supply Room(s) shall have a water sink and universal (5A & 15A) electric power plug for connection to the hand lamp. Indian Railways Telecom Manual - 2021 Page 210 16.7.6 The Power Supply Room(s) where secondary batteries are installed shall be provided with acid resistant tiles on floor and the walls up to 1.5 M. 16.7.7 A thermometer to measure the room temperature should also be kept in the battery room. 16.7.8 All cable entry points should be rodent proof. 16.8 REMOTE MONITORING AND CONTROL SYSTEM: 16.8.1 The arrangement shall be approved by PCSTE of the Railway. It shall have the following features. (a) All OFC Communication System shall have the facility of remote monitoring and control of the power plant systems. (b) The control system of the power plant shall provide following vital alarms to the remote monitoring system through NMS / Data Logger/ Mobile app/software using mobile communication facilities etc. - Mains failure - Diesel Generator failure - Battery set failure - Charger failure - Low level of fuel tank - Low Voltage - Monitoring of voltages wherever feasible (c) The control system shall be capable of accepting and reacting to following vital commands from the remote monitoring centre. - Start diesel generator - Switch off the diesel generator set - Changeover from charger no. 1 to charger no. 2 or vice versa. - Changeover from battery set 1 to battery set 2 or vice versa 16.9 MAINTENANCE 16.9.1 Maintenance of Diesel Generator Set: i.Fuel tank shall be cleaned periodically. Fuel shall be filled through a removable wire gauze filter which shall form part of fuel tank. Before filling up, unused fuel shall be decanted/replaced if the DG set has been idle for a considerable time. ii.Level of lubricating oil shall be checked (before every engine start by using a suitable dip stick, provided with the engine, wherever manual start is in vogue) and proper care shall be taken to maintain Indian Railways Telecom Manual - 2021 Page 211  desired / recommended level. Lubricating oil shall be changed periodically as per manufacturers’ data for engine hour run. iii.Diesel generator sets shall be overhauled in accordance with manufacturer’s recommendation. Checking and cleaning of parts shall be done once in every three months or as the situation warrants. It is preferable to have them overhauled by the manufacturer or his authorised representative. iv.Automatic Starting Device shall be tested periodically for effective starting during power failures and low voltage conditions. v.The no-load and on-load voltages of the alternator shall be maintained within limits and the Governor adjusted during periodic maintenance to the RPM specified and a steady output of 50Hz. The DG set shall run for 5-10 minutes on load to verify its proper working during periodic maintenance check. vi.A log book shall be maintained at every location which shall bear the history of performance and maintenance of Diesel Generator Set together with the signatures of the maintainers and SSE(Telecom). vii. Wherever auto start is not reliable, the same shall be disconnected and steps taken for manual start during power failure and also to stop the engine as soon as power supply resumes. Steps should be taken to rectify the auto start as early as possible. viii. The log book shall be maintained as per proforma given in APPENDIX-I. 16.9.2 Maintenance Of Power Supply system (a) The working of battery charger shall be checked for proper working of switches, fuses etc. (b) The power equipment shall be cleaned by a blower or any other device to remove dust. (c) Wiring shall be checked to ensure that they are in good condition and connections are properly tightened up. (d) Record of voltage and load current of all power equipment shall be maintained. 16.9.2.1 Maintenance Of Secondary Cells: (a) Cable to connect battery terminals and load should use proper colour code of wires. Red and blue wire should be used to connect positive and negative terminals. Indian Railways Telecom Manual - 2021 Page 212  (b) The battery room shall be kept well ventilated, free from water, oil and dust. Surroundings of batteries shall be kept clean. Acid proof reusable hand gloves and Hydrometer to be provided and Hydrometer Should be kept on a Wall Mounted Stand in the Battery Room. (c) Connecting cables shall be flexible and sufficiently long to prevent strain on the battery terminals. Connecting lugs shall be fitted to battery posts / terminals by using suitable nuts/bolts & tightened by using flat and spring / serrated washers. Lugs at the end of conductors, utilized for making connections, shall be crimped and/or brazed. (d) The electrical connections shall always be kept tight. Check nuts should also be used to maintain firm connections. (e) The terminals and connections of battery cells shall be coated with pure vaseline or petroleum jelly to prevent corrosion. Grease shall not be used. (f) In LMLA Battery sets, the electrolyte shall be maintained at the correct level by topping up with only distilled water as and when necessary. Electrolyte loss due to spillage shall be replenished with proper amount of electrolyte of the same specific gravity as that of remaining electrolyte in the cell. Electrolyte of proper specific gravity prepared by using industrial grade acid and distilled water shall only be added with cells in fully charged condition and after sufficient time has been allowed to cool down the cells to room temperature. Electrolyte to a cell shall be added gradually in minimum quantity so as to attain the same specific gravity as that of other cells in the battery bank after a few cycles of charge/ discharge. Electrolyte shall not be added under any other circumstances. Each cell shall be tested as per maintenance schedule so that its voltage and specific gravity are within specified limits. Test results shall be recorded in the battery history card as per APPENDIX-II. 16.9.3 Periodic maintenance schedule of Power Supply Equipments is given in Appendix-III. 16.9.4 Records And Reports: The inspector in-charge of Telecom Installation and remote control centre shall arrange to maintain: (a) The record of interruptions of main power supply and utilisation of the DG set with details of each duration. (b) Record of supply and utilisation of diesel fuel. Indian Railways Telecom Manual - 2021 Page 213  (c) Prepare monthly interruption reports of mains supply/upkeep/utilisation of DG set and send to Sr.DSTE/Dy.CSTE(Tele). 16.9.5 Records And Reports By Sr.DSTE/Dy.CSTE(Tele): Sr.DSTE/Dy.CSTE(Tele) shall analyse the monthly report and take follow up action with concerned divisional officers as to minimise the interruption of the main power supply. Consistent long duration interruptions of the main supply and the follow up action taken should be brought to the notice of Chief Communication Engineer through special reports. He will also take follow up action to overcome the other problems in order to improve the performance of telecom system to the required level of efficiency. Indian Railways Telecom Manual - 2021 Page 214  APPENDIX I _____________Railway ___________Division FUEL CONSUMPTION LOG BOOK 1. Name of Station 2. Date of Commissioning 3. Location 4. Description of Generator (Make, Capacity in KVA, Voltage, Power Factor, Speed in RPM, Frequency, No. of Phases, Type of Excitation etc.) 5. Description of Engine (Make, BHP, Speed in RPM, No. of Cylinders, Capacity of Fuel Tank, Fuel, Standard Rate of Consumption, Type of start) Date Time of Time of Close Hours Fuel filled in Signature Start worked litres Indian Railways Telecom Manual - 2021 Page 215  APPENDIX II SECONDARY BATTERY ( LMLA) HISTORY CARD ________Railway __________ Division Section _________ Battery Particulars No. of cells Installation date Capacity (AH) Circuit reference Battery set No. Charging current Battery set voltage Charger make Battery make Charger capacity Specific Gravity as Cell Voltage as per per Manufacturer’s Manufacturer’s recommendation recommendation Battery Measurement & Maintenance Cell Number Work Signature done & &Designat remarks ion Date Parameter 1 2 3 4 5 2 2 2 2 3 4 Cell Voltage Specific Gravity Cell Voltage Specific Gravity Cell Voltage Specific Gravity Cell Voltage Specific Gravity Cell Voltage Specific Gravity Cell Voltage Specific Gravity Cell Voltage Specific Gravity Indian Railways Telecom Manual - 2021 Page 216  APPENDIX III MAINTENANCE SCHEDULE FOR POWER SUPPLY SYSTEM EQUIPMENT ITEM TELECOM JUNIOR SR.SECTION TECHNICIAN ENGINEER ENGINEER Battery Cleaning of all Fortnightly - - Chargers connections Tightening of all connections Monthly - - Checking of working Weekly Monthly Quarterly Measurement of voltages & Weekly Monthly Quarterly load current Batteries Cleaning & Fortnightly - - tightening of all connections Measurement Fortnightly Monthly Quarterly of voltages and gravity MAINTENANCE SCHEDULE OF THE DG SET QUIPMENT ITEM TELECOM JUNIOR SR.SECTION TECHNICIAN ENGINEER ENGINEER Generator Measurement Fortnightly Monthly Quarterly of voltage on load/OFF load Load current -do- -do- -do- Checking of -do- -do- -do- lubricant Checking of -do- -do- -do- self-start battery Indian Railways Telecom Manual - 2021 Page 217  MAINTENANCE OF SOLAR PANEL EQUIPMENT ITEM TELECOM JUNIOR SR.SECTION TECHNICIAN ENGINEER ENGINEER Solar cell Cleaning of fortnightly - - Solar panel Measurement fortnightly Monthly Quarterly of terminal voltage of solar panel Measurement -do- -do- -do- of current of solar panel -x-x-x- Indian Railways Telecom Manual - 2021 Page 218