EARTHING AND LIGHTNING SYSTEM MAINT

Earth pit checking — "Job scope includes but not limited to the following only:a) Removal of chamber cover.b) Cleaning of earth pit area and removal of unwanted material.c) Disconnection of all the earth strips connected to earth pit.d) Measurement of earth resistance of earth pit by an earth resistance meter with valid calibration certificate.e) Connection of disconnected earth strip with washers & tightening of bolts.f) Replacement of corroded/ broken/ not available Nuts / bolts with SS 304 Nuts & SS 304 bolts along with SS 304 spring washers.g) Application of grease over nut/bolts.h) Installation of chamber cover back on earth pit.i) Stenciling of pit identification number, date of measurement, earth resistance value in ohms and next due date on chamber cover and earth pit marker.j) Stenciling shall be done on yellow base paint in black colour or on the marker as per the instruction of engineer-in- charge.k) All required material/ man power/tools is in vendor's scope."

Earthing Terminal checking — "Earth resistance and continuity measurement of earthing terminals of an equipment (i.e. motor, etc. all earthing connected), including stenciling, job scope includes but not limited to the following only:Each motor earthing consists of motor self earthings (min. 2) - motor base and junction boxes along with its field switches (Push button station) etc.b) For motors located on towers, continuity of earth circuit to be checked up to the earth bus.c) Disconnect earthing conductor (strip or wire) from the equipment (static, motor, transformer, capacitor, panel, etc.d) Measurement of earth resistance of earthing conductor by an earth resistance meter with valid calibration certificate.e) Connect the conductor back on the equipment.f) Replacement of corroded/ broken/ not available Nuts / bolts with SS Nuts & SS 304 bolts along with SS 304 spring washers. Supply of required hardware is in vendor's scope.g) Apply grease on the nut/ bolt.h) Stenciling of the date, earth resistance and next due date on the equipment (wherever available)i) Stenciling shall be done on yellow base paint in black colour. Supply of paint is in vendor's scope.j)All required material/manpower/tools are in vendor's scope."

Sign Board Installation — Job scope includes material and manpower required for grouting of sign board installation. This excludes the cost of sign board with angle which is to be claimed separately against relevant line item.

GI earth pit construction — "a) Construction of a new earth pit complete in all respects, as per the enclosed drawing and in compliance with IS 3043:2018. The work includes dismantling the existing damaged earth pit, including removal of brickwork, concrete, CI/RCC covers or frames, electrodes, etc., as applicable. It also includes excavation of the pit, supply and installation of a Class B (Medium) GI earth electrode (65 mm NB and minimum 3.2 mm wall thickness, 3m long, hot-dip galvanized with cap) along with GI clamp (as per drawing) and filling the pit with compound materials such as charcoal, salt, GI funnel/cap, and other required items. All materials are to be included in the quoted rate; no separate payment will be admissible.b) Backfilling and proper compaction of the pit is to be carried out after electrode installation. An RCC chamber of M30 grade is to be constructed around the electrode, and a mild steel or cast iron cover (thickness >6 mm) with handle is to be provided, both inclusive in the quoted rate. All required earthing connections using appropriate welding, SS 304 bolts, and necessary tools are to be completed.c) If a painted signboard is required, the cost for supply and installation shall be claimed separately under the relevant line item. Testing of the earth pit and submission of test certificates are also part of the job.d) The quoted rates shall be all inclusive covering RCC structure, CI cover, earth electrode, earthing compound, welding materials, manpower, tools, painting, and any other required components. No separate payment will be made for any of these items."

RCC structure construction — Providing and laying Cast in-situ Reinforced Cement Concrete structure around the earth electrode with M30 Grade Job includes formworks/shuttering, reinforcement steel and curing of the structure.

Earth strip laying — Laying and installation of GI Earth Strip inclusive of clamp ing at earth pit end.

Earth cable laying — Earthing cable laying all sizes

Earth strip termination — Termination of GI earth strip of all sizes on metal structure of plants. Termination will be done with nut bolts / clamps or welding. Bitumin shall be applied at t he point of joint/ termination to avoid oxidation.

"Earthing & Bonding using studS- 6000-Mumbai Refinery — Functional & protective bonding of pipes / protective bonding circuit / Functional bonding & terminal connection / earth or ground cable trays & ladders / lightning protection / any other earthing & bonding application using fully threaded studs of HILTI make like S-BT-EF M10 HL with integrated chloroprene rubber washer (resistant to UV, salt water, water, ozone. Oils, etc.) on structural steel without welding. Threaded studs should be made up of Carbon Steel 1038 & should have electroplating (Zn-Alloy) with a topcoat for chemical resistance (duplex coated). The stud should have a nut, lock washer, and conductivity disc (if required). The studs & nuts should be suitable for use in corrosion categories C1, C2 and C3 according to the standard EN ISO 9223. Fixing includes pilot drilling with a step drill bit and driving studs using stud holder, installation, and torquing of the threaded stud with integrated neoprene/ chloroprene washer using cordless, variable speed & torque, battery operated HILTI SBT 6-22 tool. The product shall be approved as per UL File Listing E257069 as earthing & bonding equipment.

Test joint for down conductor — Preparation of test joint on down conductor at man height fr om the ground. Test joint shall be strip to strip. Three nu m bers of nut bults at distance of 40mm each. Length of strip overlap shall be 180mm