BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

(6) Requirements for Design and Constructiona. The series gaps shall be so designed that for practical purposes thevarious characteristics will not alter under the change of weather conditionsb. The various parts of the lightning arrester shall be of complete moistureproof construction so that the characteristics shall not be impaired under longterm use. Sealed parts shall be so designed to prevent to ingress of moisture orwater under long term use.c. The operation counter shall be equipped on the lightning arrester in eachphase and consist of a sure current recording and measuring device, such as amagnetic link surge crest ammeter, and counter for the number of discharges ofthe lightning arrester. It shall be located at the position convenient for inspection.d. Creepage distance of bushing shall not be less than 25 mm/ kV of phaseto phase voltage. The glazing colour shall be of brown.e. Unless otherwise specified, tile characteristics and others shall comply withIEC 99-1(7) Dielectric Test Voltagea. Power frequency withstand voltage : (As per relevant IEC) kV for oneb. Lighting impulse withstand voltage :1050 kV (peak)(1.2 / 50 micro sec.)(8) AccessoriesThe following accessories shall be provided for each lightning arrester.a. Nameplatesb. grounding conductor to grounding terminalc. Operating counterd. Grounding terminale. Steel supporting structure with anchor bolts and nutsf. Other necessary accessories, if any6.3 STEEL STRUCTURE (Busbar)6.3.1 TYPEThe steel structure shall be lattice truss construction made of galvanised formedsteel and assembled by bolts and nuts.The component members of steel structure shall have inter-changeability withother identical members. The basis framing of the steel structure shall be identicalon all four (4) faces below the bend line.Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)65