How To Build A High Mast Power Plant

Transcription

1 Technical Specification HIGH MAST SYSTEM Height of mast : 20 Meter No. of sections : Two Material construction : S 355 grade as per BS-EN Base dia. and top diameter (A/F) : Top : 150 mm, Bottom : 460 mm Plate thickness & section Length : Top : 4 mm, Bottom : 5 mm Cross section of Mast : 20 side polygon. Standard for of galvanization : As per BS EN ISO 1461 Size of opening and door at base : 1200 x 250 mm Diameter of base plate : 670 mm Thickness of base plate : 25 mm Lightning protection finial : G.I single spike of length 1200 mm Max.wind speed : 62.5 m/s Number of foundation bolts : 8 nos. PCD of foundation bolts : 590 mm Type / diameter / length of foundation bolts : TS 600 / 32 mm dia / 850 mm long LUMINAIRES CARRIAGE Material of construction : 50 NB ERW Class B - M. S. Pipe Diameter of carriage ring (mm) : 710 mm (ID) Construction : 6 Arm, Welded, 2 sections Load carrying capacity : 12 Luminaire TRAILING CABLE Conductor Insulation No. of circuits per mast WINCH/ POWER TOOL Type / SWL of winch Method of operation Motor capacity No of speeds Torque limitor : Copper, 5 core, 4 sq mm : EPR insulated PCP sheathed : One : Double drum, SWL 750 Kg : Flame Proof Integral Motor : 1.5 HP : 6 Pole, Single speed : With mechanical tripping facility STAINLESS STEEL WIRE ROPE Grade / construction : AISI 316, 7/19 construction Number of ropes : Two continuous Diameter (mm) : 6 mm Braking load capacity : 2350 kg x 2 Control panel will be of Flame proof type Page 1 of 10

2 EQUIPMENT SPECIFICATION HIGH MAST LIGHTING HIGHMAST GENERAL: The scope of this specification also covers the manufacture, transport, installation, testing and commissioning of the complete lighting system, using Raising and Lowering type of High mast Towers, including the Civil Foundation Works. HPCL will only provide the supply point. However, all items required for the safe and efficient operation and maintenance of the lighting system including the high mast, whether explicitly stated in the following pages or not shall be included by the Contractor. STRUCTURE: The High mast shall be of continuously tapered, polygonal cross section, at least 20 sided. Presenting a good and pleasing appearance and shall be based on proven In Tension design conforming to the standards specified, to give an assured performance, and reliable service. The mast shall be with decorative type umbrella and suitable for wind loading as per IS 875 Part CONSTRUCTION: The mast shall be fabricated from steel plates, cut and folded to form a polygonal section, welded and shall be telescopically jointed by welding/stress fit method. The procedural weld geometry and the workmanship shall be exhaustively tested on the completed welds. Mast can be fabricated in multiple sections of length approximately 10 metres. Thus a 20 M shall be delivered in two sections. No site welding or bolted joint shall be done on the mast. The minimum Overlap distance shall be 1.5 times the diameter at penetration. The mast shall be provided with fully penetrated flange, which shall be free from any lamination or incursion. The welded connection of the base-flange shall be fully developed to the strength of the entire section. The base flange shall be provided with supplementary gussets between the bolt holes to ensure elimination of helical stress concentration. For the environmental protection of the mast, the entire fabricated mast shall be hot dip galvanized, internally and externally. The thickness of galvanizing shall be a minimum of 85 microns. DOOR OPENING: An adequate door opening shall be provided at the base of the mast and the opening shall be such that it permits clear access to equipment like winches, cables, plug and socket etc. and also facilitate easy removal of the winch. The door opening shall be complete with a close fitting, vandal resistant, weatherproof door provided with a heavy duty internal lock with special paddle key. The door opening shall be carefully designed and reinforced with welded steel section, so that the mast section at the base shall be unaffected and undue buckling of the cut portion is prevented. Size of door opening shall Page 2 of 10

3 be around 1200 x 250 mm and shall be strengthened, if required to avoid buckling of the mast section under heavy wind conditions. DYNAMIC LOADING FOR THE MAST: The mast structure shall be suitable to sustain an assumed maximum reaction arising from a wind speed as per IS 875 and shall be measured at a height of 10 metres above ground level. The design life of the mast shall be a minimum of 25 years. LANTERN CARRIAGE: a) Fabrication A fabricated Lantern Carriage shall be provided for fixing and holding the flood light fittings and control gearboxes. The Lantern Carriage shall be of special design and shall be of steel tube construction. The tubes acting as conduits for wires, with holes fully protected by grommets. The Lantern Carriage shall be so designed and fabricated to hold the required number of flood light fittings and the control gearboxes, and also have a perfect self-balance. The Lantern Carriage can be fabricated in two/three sections and joined by bolted flanges with stainless steel bolts and nylon type stainless steel nuts to enable easy installation or removal from the erected mast. The inner lining of the carriage shall be provided with suitable protective arrangement, so that no damage is caused to the surface of the mast during the raising and lowering operation of the carriage. The entire Lantern Carriage shall be hot dip galvanized after fabrication. The design shall provide a perfect balance for the lantern carriage during raising and to lowering also. b) Junction Box Weather proof junction box, made of Cast Aluminium shall be provided on the Carriage Assembly as required from which the inter-connections to the designed number of the flood light luminaires and associated control gears fixed on the carriage shall be made. c) Raising and lowering mechanism For installation and maintenance of luminaries and lamps, it will be necessary to lower and raise the Lantern Carriage Assembly. To enable this, a suitable Winch Arrangement shall be provided, with the winch fixed at the base of the mast and the specially designed head frame assembly at the top. Suitable end limit switches shall be provided to trip the winch motor at both top & bottom ends of the designed travel. Suitable thermal relay shall be provided to trip the mechanism in case of overload. d) Winch The winch shall be of completely self-sustaining type, without the need for brake shoe, springs or clutches. Individual drum also should be operated for fine adjustment of lantern carriage. The capacity, operating speed, safe working load, recommended lubrication and serial number of the winch shall be clearly marked on each winch. The winch shall be self-lubricating type by means of an oil bath and the oil shall be readily available grades of reputed producers. The winch drums Page 3 of 10

4 shall be grooved to ensure perfect seat for stable and tidy rope lay, with no chances of rope slippage. The rope termination in the winch shall be such that distortion or twisting is eliminated and at least 5 to 6 turns of rope remains on the drum even then the lantern carriage is fully lowered and rested on the rest pads. It should be possible to operate the winch manually by a suitable handle and by an integral/ external power tool. It shall be possible to remove the double drum after dismantling through the door opening provided at the base of the mast. Also, a winch gearbox for simultaneous and reversible operation of the double drum winch shall be provided as part of the contract. The winch shall be type tested in presence of a reputed Institution and the test certificates shall be furnished before supply of materials. A test certificate shall be furnished by the Contractor form the original equipment manufacturer, for each winch in support of the maximum load operated by the winch. e) Head Frame The head frame, which is to be designed as a capping unit of the mast, shall be of welded steel construction, galvanized both internally and externally. The top pulley shall be of appropriate diameter, large enough to accommodate the stainless steel wire ropes and the multi-core electric cable. The pulley block shall be made of non-corrodable material, like diecast Aluminium Alloy (LM-6). Self-lubricating bearings and stainless steel shaft shall be provided to facilitate smooth and maintenance free operation for a long period. The pulley assembly shall be fully protected by a canopy galvanized internally and externally. Close fitting guides and sleeves shall be provided to ensure that the ropes and cables do not dislodged from their respective positions in the grooves. The head frame shall be provided with guides and stops with PVC buffer for docking the lantern carriage. f) Stainless Steel Wire Ropes The suspension system shall essentially be without any intermediate joint and shall consist of only non-corrodable stainless steel of AISI 316 or better grade. The stainless steel wire ropes shall be of multi strand construction, the central core being of the same material. The overall diameter of the rope shall not be less than 6 mm. The breaking load of each rope shall have factor of safety of over 5 for the system at full load. The end Constructions of rope to the winch drum shall be fitted with talurit. The thimbles shall be secured on ropes by compression splices. Two continuous lengths of stainless steel wire ropes shall be used in the system and no intermediate joints are acceptable in view of the required safety. No intermediate joints / terminations, either bolted or else, shall be provided on the wire ropes between winch and lantern carriage. ELECTRICAL SYSTEM, CABLE AND CABLE CONNECTIONS A suitable terminal box shall be provided as part of the contract at the base compartment of the high mast for terminating the incoming cable. Supply of Incoming cable from the substation/ supply point to the highmast comes under the scope of the party. All necessary items shall be supplied by the party for drawing power from the Page 4 of 10

5 dummy feeder at the substation. Cable laying in the trench, sand filling & brick laying comes under the scope of the contractor. The electrical connections from the bottom to the top shall be made by special trailing cable. The cable shall have enough flexibility and endurance, and have copper conductors. The cable shall be of reputed make. At the top there shall be weather proof junction box(es) to terminate the trailing cable. Connections from the top junction box to the individual luminaries shall be made by using 3 core flexible PVC cables of adequate size. The system shall have in-built facilities for testing the luminaries while in lowered position. Also, suitable provision shall be made at the base compartment of the mast to facilitate the operation of externally mounted, electrically operated power tool for raising and lowering of the lantern carriage assembly. The trailing cables of the lantern carriage rings shall be terminated by means of specially designed, metal clad. Multi-pin plug and socket provided in the base compartment to enable easy disconnection when required. A distribution board with suitably rated 3-phase incomer MCB and separate MCB's controlled folders for lighting and power tool shall also be supplied. The board shall Incorporate timer for control of lighting and control circuit for winch operation with all necessary contactors etc. The board shall have IP 55 protection with rainwater protections canopy and epoxy powder coated suitable for outdoor mounting in coastal area. The work shall also include necessary foundation cable glands,etc. complete as required. POWER TOOL FOR THE WINCH A suitable, high-powered, electrically driven internally mounted power tool, with manual over ride shall be supplied for the raising and lowering of the lantern carriage for maintenance purposes. The speed of the power tool shall suit the system. The power tool shall be single speed provided with a motor of the required rating. The power tool shall be supplied complete with push button type remote control switch, together with 5/6 metres of power cable, so that the operations can be carried out from a safe distance of 5 (five) metres. The capacity and speed of the electric motor used in the power tool shall be suitable for the lifting of the design load installed on the lantern carriage. The power tool mounting shall be so designed that it will be not only self-supporting but also aligns the power tool perfectly with respect to the winch spindle during the operations. Also, a handle for the manual operation of the winches in case of problems with the electricityoperated tool, shall be provided and shall incorporate a torque-limiting device. There shall be a separate torque-limiting device to protect the wire ropes from over stretching. It shall be mechanism with suitable load adjusting device. The torque limiter shall trip the load when it exceeds the adjusted limits. There shall be suitable provision for warning the operator once the load is tripped off. The torque limiter is a requirement as per the relevant standards in view of the overall safety of the system. High mast shall have its own power tool motor. LIGHTNING FINIAL One number heavy duty hot dip galvanized lightning finial shall be provided for the mast. The lightning finial shall be minimum 1.2 M in length or as required so that the lantern carriage also comes within the safety zone and shall be provided at the centre of the head frame. It shall be bolted solidly to the head frame to get a direct conducting path to the earth through the mast. The lightning finial shall not be provided on the lantern carriage under any circumstances in view of safety of the system. Page 5 of 10

6 AVIATION OBSTRUCTION LIGHTS Approved LED type Single dome Aviation Obstruction Lights of reliable design and reputed manufacturer shall be provided on top of each mast. EARTHING TERMINALS Suitable earth terminal using 12 mm diameter stainless steel bolts shall be provided at a convenient location on the base of the Mast, for lightning and electrical earthing of the mast. The mast shall be provided with duplicate earthing including necessary earth pits as per IS. FOUNDATION FOR HIGH MAST The scope also includes supplying all materials and casting of RCC foundation along with necessary Anchor bolts etc. The detailed drawing for the foundation should be submitted and got approved by HPCL before starting of the work. FEEDER PILLAR DISTRIBUTION BOARDS DESIGN CRITERIA: The feeder pillar distribution boards shall be sheet steel enclosed, outdoor type having suitable canopy for rain water protection, pedestal type, FLP type conforming to IP: 55 suitable for use on 415V, 50 Hz., 3 phase, 4 wire AC system. The board shall have TPN / DP isolator / switch fuse unit / MCB as incoming and TPN / SP MCB as outgoing feeders. These boards are meant for lighting the High Masts. These shall be factory built standardized boards or fabricated based on specification and approved drawing. The feeder pillar box shall be approved by CCOE. The feeder pillar box shall have required interface for remote control PB station through cable for raising and lowering of lantern carriage. The feeder pillar box shall be mounted on a raised concrete platform above ground level at min height of 1 meter. The light fittings provided on the light mast shall have individual switch controls in the feeder pillar box to have the flexibility to put the selected light fittings ON / OFF. Three phase supply to be equally distributed to the 12 light fittings alternatively (eg: light Fittings 1,4,7,10 to R-phase; 2,5,8,11 to Y-Phase; 3,6,9,12 to B-Phase ) to ensure equal light coverage in all directions even if one phase supply is available. One Feeder pillar at VDS requires separate provision for outgoing supply through 4 core cable to the feeder pillar of second highmast. CONSTRUCTIONAL DETAILS: a) The lighting distribution boards shall be pedestal mounted type made of minimum 1.6 mm thick sheet steel totally enclosed rain, dust and vermin proof construction having separate chambers for incoming and outgoing feeders. b) The board shall conform to IP: 55 class of protection as per IS: 2147and suitable canopy for rain water protection. c) The board shall be fabricated using high quality CRCA sheet steel. Suitable neoprene gaskets shall be provided for all doors and covers for making the board dust proof. Page 6 of 10

7 d) The operating handle of the incoming switch fuse unit shall be accessible from the front side.operating handle shall be suitably interlocked mechanically with the door of the incomer chamber so that the door can be opened or closed only when the switch is in 'OFF' position. A manual interlock defeat shall also be provided. e) The outgoing MCB's shall be housed in a separate chamber. The operating knobs of the MCB's shall be accessible through front door. The outgoings chamber shall be covered completely with FRP sheet. The 4mm thick FRP sheet provided shall effectively shroud all the live parts against accidental contact. The door shall have pad looking facility. f) Bus bars shall be of Tinned copper. Bus bars shall be shrouded. Phase & neutral Busbars shall have the same cross sections. The earth bus shall have the same size as the Neutral bus. g) The incoming compartment door shall have 3 Nos. (for 3 phase) 1 No. (for single phase) Neon indicating lamps (red colour). h) Safety clearances as per IE rules shall be provided for components of the board. i) Board shall have continuous earth bus of size same as that of neutral. j) Link between neutral and earth shall be provided. PAINTING : The final painting of all boards shall be light siemens grey RAL 7032 IS: 5 unless otherwise specified. TESTING : All the distribution boards shall be tested as per IS:8623 at factory site. FLOOD LIGHT LUMINAIRE (SUITABLE FOR HPSV/MH T LAMPS) The flood light fitting shall be integral or non-integral type, complete with suitable weatherproof control gearbox. The fitting shall consist of a lamp compartment housing a reflector made of spun aluminium electrochemically brightened and anodized. Flat toughened front glass suitable to withstand the high temperature and humid conditions shall be fixed to the housing using neoprene gasket. Focusing knob to help in adjusting the lamp center shall be provided. Mild steel cradle shall be mounted on the control gear. The control gear shall consist of heavy-duty polyester filled copper choke suitable for lamp wattage specified p.f. improvement condensers. The minimum power factor required is 0.9 for all light fixtures connectors and fittings duly wired with provision of cable entry provided. The provision for relamping is to be made in such a way that aiming angles not disturbed. The chokes shall be manufactured from high quality silicon laminations with tapping at 200/220/240V; this shall conform to IS Holders shall be made out of porcelain and shall have brass contacts. These shall be rated for 240V. The tip of the holder shall be spring-loaded. Capacitors shall be of 250 V rating. This shall have fiberglass covered wire of suitable cross section to withstand high temperature generated in the control gear/lamp holder. The main supply shall be connected to the terminal book made out of porcelain/ bakelite of suitable quality. The terminal block housing shall have flexible conduit for taking the main supply leads. The control gear and lamp holder housing shall be provided with a sufficient number of vertical fins to dissipate heat produced. A protractor plate with degrees marked on it shall be provided to enable the fitting to be tilted to any required angle. Rotating of the fitting shall be limited to 360-degree horizontal and 180- degree vertical and locking arrangement shall be provided for both vertical and Page 7 of 10

8 horizontal position. All hardware shall be made of mild steel and passivated. The fitting shall be complete and suitable for taking HPSV lamp, provided with gaskets to make the unit weatherproof. All the cast aluminium parts shall be finished in epoxy powder coating, 3 x 2.5 sq.mm PVC cable, copper conductor shall connect the terminals of the luminaries with sub circuit at 240 V via the control gear unit, 1 no. earthing terminal shall be provided. Both the luminaries and the control gearbox shall conform to IP 54 or better and suitable for outdoor application. The control gearbox shall have the required electronic igniter for starting of the lamp. FLOOD LIGHT LUMINAIRE (SUITABLE FOR LED LAMPS) The flood light fitting shall be integral or non-integral type, complete with suitable weatherproof control gearbox. The fitting shall consist of a lamp compartment housing a reflector made of spun aluminium electrochemically brightened and anodized. Flat toughened front glass suitable to withstand the high temperature and humid conditions shall be fixed to the housing using neoprene gasket. The minimum power factor required is 0.9 for all light fixtures connectors and fittings duly wired with provision of cable entry provided. The control gear and lamp holder housing shall be provided with a sufficient number of vertical fins to dissipate heat produced. All the cast aluminium parts shall be finished in epoxy powder coating, 3 x 2.5 sq.mm PVC cable, copper conductor shall connect the terminals of the luminaries with sub circuit at 240 V via the control gear unit, 1 no. earthing terminal shall be provided. Both the luminaries and the control gearbox shall conform to IP 54 or better and suitable for outdoor application. Proper Surge and over current protections to be provided for the lumaire. The luminaire shall be approved by Site-engineer/ project incharge of HPCL. TIMER Timer (Time switch) shall be accurate & quartz driven. The timer shall have a built-in chargeable Ni-Cd cells for 150 hours continuous operation in the event of power failure. The timer shall be suitable for switching ON/OFF highmast etc. at predetermined time. The timer shall be supplied with enclosure or panel mounted as required. CONTROL PANEL HOUSING, CONTROL CKT S A suitable control panel housing for control circuits shall be provided for safe & efficient Operation of the highmast. It should also consist suitable control for the power tool motor with Contactors. LAMP SODIUM VAPOUR LAMP : The lamps shall be suitable for universal burning position and shall be colour corrected and shall have caps E-40 with ES/GES threads. All the lamps shall be suitable for external igniter. Lamps shall be ovoid or tubular type as specified. The approved makes of lamps is limited to the following only. 1.) Philips 2.) Crompton Page 8 of 10

9 3.) Bajaj HIGH POWER LED LAMP : LED luminary shall be a High power LED type and of 200W rating. LED inside the lamp shall be of Philips/Osram make with proper surge and over current protection. The lamp shall be approved by Site-engineer/ project incharge of HPCL. EARTHING Earthing shall confirm to IS MATERIAL REQUIRED FOR AN EARTH PIT a) 65 mm diameter, Gl pipe, 3.00 meters long in one single piece with (40 x 6)/ (25 x 6) mm GI flat of required length welded to the pipe on top and 12 mm holes made on all sides of the pipe at 150 mm apart upto height of minimum 2.5 meters from bottom... 1 No. b) Bolts, nuts, washers and sockets for earthing connection... 1 set. c) Charcoal of not less than 12 mm size d) Salt granular. e) 80 mm long funnel having suitable diameter with wire mesh welded at top and GI nut welded at bottom (to fit the GI pipe electrode). f) RCC cover for earth pit chamber 1 no. METHOD OF ERECTION a) The pit for an earth electrode will be dug with its center normally at minimum 2.5 meters away from the edge of any building/ masonry work. b) The GI pipe will be erected vertically at the center of the pit, with top of the pipe minimum 200 mm below ground level. c) Alternate layers of charcoal and salt each 150 mm, will be put into the pit beginning from the bottom of pit, around the pipe to cover the same upto minimum 3.0 meters length from bottom. Alternately charcoal and salt shall be thoroughly mixed at site and poured into earth pit. d) The space above the salt / charcoal layers will be filled with loose sandy soil, upto a level of 550 mm from ground level. e) A cement concrete chamber of inner dimension 350 x 350 mm will be erected around the top of the earth pipe so that top surface of the chamber is flushed with the outside finished ground level. f) A GI earthing strip (40 x 6) I (25 x 6) mm, of required length size will be tightly connected to the electrode GI plate by means of GI bolt. nuts and washers. End of this GI strip will be welded to the earthing ring GI wires / strip. In areas of rocky terrain, where it is not possible to vertically drive the electrode, horizontally installed electrode at a minimum depth of 1000 mm may be provided as per the instruction offsite engineer. Alternately bentorite or chemical treatment to obtain ohmic value-as required shall be done. Page 9 of 10

10 EARTHING RING MAIN The earthing ring shall be made by GI strip/ insulated single core cable of specified size. The ring shall be laid in the cable trench along with lighting cable and connected to all the earthing pits. EARTHING OF FEEDER PILLAR DISTRIBUTION BOARDS The distribution board shall be provided with two separate earth terminals. An earth busbar of appropriate cross section shall be provided inside the lighting board and connected to the earth terminals provided on either side of the board. Adequate number of holes/ terminals shall be provided on earth bus with suitable provision for terminating the earth wire. GI strip/ GI wire insulated single core cable of suitable size shall be used for earthing the lighting board, by connecting the two earth terminals separately to the earthing main in the shop/earth pit. EARTHING OF LIGHT FIXTURES The single core PVC insulated wire/ bare copper wire or 14 SWG GI wire and the third core of the flexible wiring cable shall be used for earthing the light fixtures. EARTHING OF METAL BOXES & BRACKETS Not less than 14 SWG Gl wire or suitable size PVC insulated copper wire shall be used for earthing a U metal boxes and brackets. Page 10 of 10