REPAIR/ MAINTENANCE OF HT DISTRIBUTION SYSTEM INCLUDING REPAIRS /REWINDING TO TRANSFORMERS, GODs, LAs, EARTHING AND ALLIED WORKS AT 2 MW SOLAR PLANT AND ADJOINING AREA UNDER AGE E/M NO II OF GE (UTILITY) SECUNDERABAD

Amount

Excavation in trenches not exceeding 1.5m wide and not exceeding 1.5m in depth and getting out in hard/ dense soil for foundation of poles, structures, stay rods, laying of underground cable etc complete all as directed.

Returning, filling in soils including spreading, leveling, watering and well ramming in layers each not exceeding 25cm thick complete all as directed .

Removing excavated soil to a distance not exceeding 50m and depositing where directed at a level not exceeding 1.5m above the starting point complete all as directed.

M&L filling sand/Stone dust in trenches for sand cushioning of laying of cables to the full width of excavated trench 8 cm thick before laying the cable and 15 cm above the cable, gently punned down complete all as specified and directed. Note :- Thickness of sand cushion after punning down (i.e 18 cm) shall be measured for payment.

M&L in repairs for laying un-reinforced precast concrete cable cover, class HV , type 1 with , size 300 mmX180mmX 40mm complete all as directed .

Supply, lay in replacement of GI tubing 100 mm dia, light grade for cable protection at road crossing / on poles and tubing sealed at both ends after laying the cables complete all as directed

Supply & Fixing in replacement of Disc insulator, 33 kV grade, porcelain vitreous, nominal diameter 255 mm, unit spacing 146 mm, creepage ≥ 295–320 mm, with galvanized cap & pin, conforming to IS 731 complete all as directed .

Supply & fixing in replacement pin type insulator 33 KV grade porcelain vitreous brown or green insulator including one galvanised iron washer and one nut, 150 mm high and 150 mm dia including taking out old unserviceable one, complete all as directed

Supply and fixing in replacement of post-top porcelain insulator, 33 kV grade, vitreous brown glazed type, conforming to IS:2544, complete with galvanized iron clamp, nuts, bolts, and washers, suitable for outdoor installation, including removal of unserviceable insulator, disconnection and reconnection of electrical supply, and restoration of service, complete all as directed

M&L for earthing complete with GI earth plate electrode of size 60cm x 60cm x 6 mm thick burried directly in ground (earth pit not less than 2.25 m deep below ground level) with top edge of the plate not less than 1.5m below the normal ground level connected with GI strip 32 x 6mm by means of bolts, nuts, check nuts & washers of galvanished iron steel including necessary excavation and earth work in any type of soil, removing surplus soil to a distance not exc 50m, with and including PCC chamber in PCC (1:2:4), type B1,using (20mm graded stone aggregate),"mild steel angle iron frame" made out of MS angle iron of size 40x40x6mm thick duly painted with two coats of synthetic enamel paint over one coat of red oxide zinc chrome primer hinged with and including 6mm thick CI cover with handle, watering arrangement with funnel internally secured with wire mesh with 20mm dia medium grade pipe for watering 40mm dia light grade, GI pipe for lead protection in and including alternate layers of charcoal dust and common salt complete all as shown in electrical "plate No '3' and connected to earthing test point all as specified and indicated including testing on completion including retrieving old GI earth plate, CI cover, GI pipes, angle iron frame from existing earthing complete all as specified and directed.

Dismantling and taking out old UNSV GI Strip and Supply,fix earth continuity conductor or main earthing lead fixed to wall on batten or fixed to pole GI strip 32 x 6 mm complete with S&F of suitable fixing arrangement, nuts, bolts and washers etc all as specified and directed.

Dismantling and taking out old unserviceable lightning arrester and supplying, fixing, connecting, and testing 30 KV/ 10 KA station class-II heavy duty, self-supporting outdoor lightning arrester suitable for 33 kV system, having rated voltage 33 kV (RMS), maximum continuous operating voltage (MCOV) not less than 30 kV (RMS), discharge current 10 kA, with highly non-linear ceramic ZnO resistors hermetically sealed, complete with metal base, base insulator, terminals for ground connection, pressure relief arrangement, and fixing with suitable nuts, bolts, and washers, complete all as specified and as directed by the Engineer-in-Charge, conforming to IS 3070 (Part 1 & 2).

M&L of cross arms i.e bracing supporting clamps back plates, nuts, bolts and washers complete including one under coat and one finishing coat with synthetic enamel paint over a coat of red oxide primer & including taking down old unserviceable complete all as directed .

Material and labour for supplying and fixing ACSR jumpers inreplacement of defective one for 33 kV overhead line, matching the size of the existing conductor, including galvanized binding wire, nuts, bolts, and washers, complete in all respects as directed, conforming to IS 398 (Part 1 & 2) for ACSR conductors and IS 5613 for line fittings.

Dismantling and taking out old UNSV danger notice board and M&L of danger notice plate of 1.6mm thick mild steel sheet vitreous enameled white, with letters, figures Supply and fixing of conventional ‘Skull and Bones’ danger plate in signal red color, size 25 × 20 cm, for 33 kV overhead/high-tension line, complete with mild steel clamps, bolts, and nuts of approved size, as specified and directed, conforming to IS:2551-1982

Material and labour in repairs for supplying and fixing ACSR (Aluminium Conductor Steel Reinforced) conductors for 33 kV overhead line on poles, including stretching and tightening of conductors, installation of insulators, binding with suitable galvanized wire, and removal of old/unserviceable ACSR conductors. Complete in all respects as specified and directed, conforming to IS 398 (Part 1 & 2) for ACSR conductors and IS 5613 for fittings.

material and labour in repairs Top cover gasket and gaskets set fo conservator tank etc complete of for 79-1250 KVA capacity transformer as per site requirement.

Supply and fixing in repairs of temperature gauge, 0–100 °C, suitable for 33/0.433 kV distribution transformer, with 6″ stem, complete with mounting and connection, as specified and directed.

Supply and fixing in repairs of porcelain transformer HT bushing, 33 kV class, suitable for indoor/outdoor oil-immersed transformer up to 1250 kVA, complete with brass set stems, conical bush/gasket, as specified and directed.

material and labour in repairs LT rod / studs for any make of transformer rating up to 1250 KVA mounted on pole/plinth, made of brass with nut, cup and washers and fittings etc as per size and shape of original complete including taking down old u/s one complete all as directed.

Supply and Fixing in repairs in renewal silca jel breather assembly with vent pipe for indoor/outdoor transformer of 1250 KVA of size 500g capacity including silicagel complete all as directed.

Supply and filling in replacement / top up of transformer oil as per IS :335 with 70KV di-electric strength complete in transformer plinth / pole mounted including testing insulation and vescocity of oil all as specified and directed

M&L for Dehydration including filtration cleaning of transformer oil , testing of di-electric strength of transformer oil of indoor/Outdoor type transformer 11KV/433 volt. Filtration of transformer Oil by passing through filtration Machine/Plant to remove moisture , impurities and for improving di-electric strength to above 70 Kv for 2mm gap and machine having minimum Capacity 1000 to 30000 Ltr/hrs. Testing of insulation and vescocity of Oil before and after dehydration to be carried out site. Note to be added : Contractor Carryout the filtration at site by on line machine with giving printouts of di-electric strength shall cost quoted in unit rate only.

M&L for cleaning/Painting of 4 pole structure /2 Pole structure/single Pole structure of any type/size/length and removing existing painting by using wire brush using with emery paper and cleaning with chemical agents, after cleaning the poles two coats of red oxide primer and two coats of synthetic aluminium painting satisfactorily by Engr-in'Charge and Painting work carryout at any height and including marking of pole numbers as directed and safety eqpts & tools will be own arrangement and marking and colour washing of pole coping all as specified and directed of the following.

Two poles with cross Arms

Four Poles with cross Arms

Single HT 13 mtr Pole with cross Arms

Inspection of defective 33kv HT cable(laid in UG/trench/tunnel/wall/surface) to locate the fault using cable fault Locator machine(by surge generators mounted on Van) (fault either by Short/Moisture/earth fault or any type) including complete all as directed.

Inspection of defective LT cable (laid in UG/trench/tunnel/wall/surface) to locate the fault using cable fault Locator machine(by surge generators mounted on Van) (fault either by Short/Moisture/earth fault or any type) including complete all as directed.

M&L for Spray painting of upto 1250 KVA transformer pole mounted / plinth mounted at site and applying two coat of synthetic enameled Smoke grey paint after removing all dust & rust and paint including marking or transformer capacity with stencil letter with black or white paint and Font and Size of letter shall be directed complete all as specified and directed.

Maintaining a minimum clearance of 15 m on either side of the 33 kV overhead line by cutting, trimming, and removing tree branches and vegetation, taking proper line clearance, removing branches falling directly on the OH line, and carrying out restringing of conductors if required, with restoration of supply after completion of work; all activities shall be carried out strictly in compliance with safety protocols including obtaining prior shutdown and line clearance from competent authority, use of approved PPE such as safety helmets, gloves, insulating shoes, face shields and safety harnesses, deployment of insulated tools and equipment suitable for 33 kV operations, proper earthing and discharge of lines before commencement, engagement of certified linemen and supervisors trained in high-voltage line maintenance, and ensuring immediate safe restoration of supply after testing, all safety measures deemed to be included in the quoted rate. Note: Restringing will be measured and paid under relevant items of schedule

Restreching/Restringing, tightening and repair to overhead line ACSR conductor of any size on HT/LT poles including necessary Aluminium binding wire connectors PVC sleeves for jumper, fixing of insulators and prunning of tree complete all as specified and directed.

Material and Labour in replacement Anti-climbing device; spikes type fabricated out of M.S. bars (round, square and flat) including nuts, bolts, washers and welding in two halves made to shape to suit the cross section of the pole complete all as specified and directed.

Inspection, functional testing, systematic diagnosis, repair or replacement of defective accessories and critical components of the 2 MW Solar Power Plant to restore the plant to its rated performance, operational safety, and long-term reliability to ensure that all inverter subsystems, power electronics, protection devices, control circuits, and monitoring interfaces function seamlessly and withstand the environmental and electrical stresses associated with large-scale PV operation.

IGBT modules conforming to IEC 60747-9 standards, rated for 1200 V and 75–150 A. to perform high-speed switching operations to convert direct current (DC) power of SPV modules into alternating current (AC) suitable for grid integration or local distribution.

Reverse polarity protection diodes conforming to IEC 60747-2, with a voltage rating of 1000 VDC and current handling capacity of 50–100 A.

DC terminal blocks conforming to IEC 60947-7-1 standards, rated for 1000 VDC and 40 A to serve as critical connection interfaces between incoming PV string cables and the DC bus of the combiner box/inverter, ensuring safe, reliable, and maintainable electrical connectivity in the solar plant’s DC distribution system.

DC Surge Protection Devices (SPDs) conforming to IEC 61643-31 .The SPD shall be Type 2, rated for 1000 VDC with a discharge current capacity of 40 kA, to protect solar photovoltaic systems against lightning-induced surges and switching transients.

Cooling fans conforming to IEC 60730-2-14 rated for 24 VDC or 48 VDC, 1–2 A, for maintaining safe thermal operating conditions in solar inverters, DC combiner boxes, and power electronic assemblies.

Temperature sensors conforming to IEC 60751 (Industrial platinum resistance thermometers and platinum temperature sensors) with Negative Temperature Coefficient (NTC) thermistors or PT100 resistance temperature detectors (RTDs),for continuous monitoring of heatsink and semiconductor module temperatures in solar inverters. Operating range: –40 °C to +125 °C.

Main Control Printed Circuit Board (PCB), in compliance with IEC 61508 for central control unit of the inverter, running critical algorithms and safety functions

Voltage sensor circuit IEC 60688 rated for 0–1000 VDC (PV side) and 0–400 VAC (grid side) for inverters.

Hall Effect-based current sensors conforming to IEC 61800-5-1 rated for 0–100 A, in solar inverter systems for monitoring, control of AC and DC Currents and protective functions.

Communication module to provide reliable data exchange between the inverter control system and the plant data monitoring / SCADA system. 5V or 12V DC supply and supports RS485 serial communication (Modbus RTU protocol) as well as Ethernet (IEEE 802.3) connectivity for local and remote monitoring.

Relay boards conforming to IEC 61810 (Electromechanical elementary relays). 24 VDC control supply.

Fuse holders conforming to IEC 60269-2 rated up to 32 A to mount and secure PV string protection fuses

High Rupturing Capacity (HRC) fuses rated at 32 A afor PV string protection

Industrial-grade solar data logger system, complete with an integrated 24 VDC UPS backup system, protective relay circuits, RS485 communication terminals for MODBUS/SCADA connectivity, and Type 2 DC Surge Protection Device (SPD) in compliance with IEC 61643.

Pyranometer, designed for accurate measurement of global solar irradiance at the Earth’s surface. It shall support continuous monitoring of performance ratio (PR) and index measurements of the PV plant, with compatibility for integration into the existing data monitoring system. The scope includes mounting accessories, cabling and all terminations as required at site, for solar resource measurement.

Weather monitoring system, capable of accurately recording and transmitting critical meteorological parameters for solar plant performance analysis. The system shall include sensors for ambient temperature, module surface temperature, relative humidity, wind speed, wind direction, and rainfall, along with provision for solar radiation input from pyranometer(s). The equipment shall be designed for continuous outdoor operation, with UV-resistant housing, IP65/IP67 protection class, and low temperature coefficient sensors to ensure reliable measurements under varying environmental conditions. The weather monitoring unit shall support data logging, real-time communication via RS485/MODBUS/Ethernet, and seamless integration with the central SCADA/data acquisition system. The scope shall also include mounting on existing structures, cabling, terminations, surge protection devices, and calibration certificates, ensuring compliance with IEC 61724.

ESE Lightning Arrester to safeguard solar plant structures and equipment. The arrester shall conform to IEC 62305 / NFC 17-102 standards, and the scope shall include all accessories such as down conductors, earthing electrodes, surge protection devices, connectors, clamps, and civil foundation work as required at site for complete and reliable installation.

6 sqmm single-core, solar-grade, XLPO insulated, UV-resistant, flame-retardant DC cable rated for 1000 VDC (Positive& negative polarity), including termination with suitable MC4 connectors and accessories as required at site includung earth work .

Three-phase 33 kV ICOG VCB panel, protection relays, and IGBT modules include replacing faulty contacts and IGBT units, repairing associated wiring and cooling systems, and conducting functional tests with relay software complete. C&S model No CSENEX-250 or equivalent in Schneider and L&T

Material and labour for repair and maintenance of the DC string cabling from PV panels to inverter INV7S1, including tracing and isolating defective/damaged cables, dismantling unserviceable portions, and laying of new solar-grade XLPO insulated, UV-resistant, flame-retardant DC cable rated for 1000/1500 VDC of suitable cross-section through approved HDPE/PVC/GI conduit including necessary excavation, backfilling, and reinstatement of surfaces as required. The scope also includes supply and fixing of conduit accessories, proper terminations using MC4 connectors/lugs, polarity checks, insulation resistance testing, and torque-tightening of connections to ensure secure and safe operation. On completion, the contractor shall carry out continuity, polarity, and performance testing of the string and restoring reliable power transfer from the PV panels to the inverter.

Same as Item No 32 above but from PV modules to PCU7S8 inverter string,

Same as Item No 32 above but from DC string cabling from PV panels to PCU10S5 inverter string

Same as Item No 32 above but from DC string cabling from PV panel to Semiconductor 14S5 inverter string,

Same as Item No 32 above but from DC string cabling from PV modules to PCU8S1 inverter string,

supply and laying, including jointing and termination, of 25 mm × 3 mm copper earth strip, manufactured from high-conductivity, annealed copper. The strip shall be of high ductility, corrosion-resistant, and bare type with radiused edges for safe handling, suitable for use in earthing and lightning protection systems.

Supply in replacement of unserviceable spare parts for VCB

Opening/Closing push button Assly

Limit Switch Assly including connected control wiring etc

TNC Switch

Closing Coil

Auxiliary Switch with link

Tripping Coil

Thermostat

Spring return latch Assy

Strip heater 230V, 80 Watt

Indicating Lamps LED Type

Support insulator

Healthiness test of whole HT 11 KV installation such as VCB by injecting artifical HT supply complete all as specified and directed.

M&L in repairs for ACB panel thorough cleaning of the surface to remove all dirt, loose deposits, rust, and deteriorated paint by wire brushing, scraping, or sanding, followed by the application of rust remover/convertor wherever necessary. After proper surface preparation, one coat of approved epoxy-based zinc chromate primer or equivalent anti-corrosive primer shall be applied, followed by two coats of industrial-grade anti-corrosive enamel/epoxy paint of approved make and shade, suitable for outdoor service conditions. During painting, all instruments, nameplates, meters, semaphore indicators, and operating handles shall be properly masked and protected, and on completion, all identification markings, panel numbers, and safety labels shall be restored to their original condition.

M & L for XLPE insulated, screened, PVC bedded, galvanised steel strip or wire armoured, electric power cables (heavyduty) with aluminium conductor, 11000 volts Earthed, grade cross sectional area sq. 300mm 3 core complete all as specified and directed.

Supplying and laying synthetic Rubber insulated mats 3 mm thick for voltage upto 33 kv for electrical purpose as per IS 15652-2006, (superseding IS 5424) suitable for electrical shock safety of sizes 2m x 1m.

M&L for Cable jointing kit for 33 KV (earthed) grade cable for outdoor end termination heat shrink type joint complete with jointing material and accessories suitable for 3 core XLPE armoured aluminium conductor cable of size 300 Sqmm including taking out old u/s one complete all as directed

M&L for Cable jointing kit for 33 KV (earthed) grade cable for indoor termination heat shrink type joint complete with jointing material and accessories suitable for 3 core XLPE armoured aluminium conductor cable of size 300 Sqmm including taking out old u/s one complete all as directed

Cutting anxious green growth / vegetation growth for cleaning out the area around transformer installations and four pole structure yards at ground level by cutting out roots, un wanted plants bushes and removal of the same by surface excavation not exceeding 30 cm deep average 15 cm complete.

Srinivasa Consructions (BID ID -3474132)

M. Laxman Rao and sons (BID ID -3470499)

DPS sales and services india (BID ID -3480520)

LEOENTERPRISES (BID ID -3474573)

L and S ENTERPRISES (BID ID -3473551)