BANGLADESH POWER DEVELOPMENT BOARD TENDER ... - BPDB

6. 230 kV OUTDOOR SWITCHGEAR, EQUIPMENT6.1 GENERALThe contractor shall furnish the 230 kV outdoor switchyard equipment which shallcomply with as listed below or relevant IEC standard and the 230 kV equipmentshall be arranged in the outdoor as shown on the attached drawings or asdirected by the Board.6.1.1 DESIGN EQUIPMENT(1) System VoltageThe system shall be as follows:- Nominal system voltage : 230 kV- Highest system voltage : 275 kV(2) Insulation levelThe insulation level of the switchgear, equipment shall be as follows:Lighting impulse withstand test: 1050 kV(Peak)Voltage (1.2 / 50 micro sec.)- Power frequency insulation level(for 1 mm.) : relevant IEC kV(3) Outdoor Conductor Clearance- Phase to phase, standard :3000 mm- Phase to phase, minimum :2100 mm- Phase to ground, Standard :1900 mm- Phase to ground, Standard :1200 mm(4) Design ConditionsSwitchgear equipment shall be designed to avoid local corona formation anddischarge likely to cause radio interface, and to endure short circuit currentwithout thermal and mechanical failure for one (1) second. All cubicles andenclosures shall be vermin proof, dust resistance and weatherproof.6.2 230 kV SWITCHGEAR, EQUIPMENT6.2.1 230 kV CIRCUIT BREAKERS(1) TypeThree (3) pole, dead Tank type, high speed, outdoor, trip free in any position,hydraulic & spring operated SF 6 gas puffer, single flow type complete withhydraulic pump, tank, piping, conduit, wiring, and all other necessary accessories.(2) UseFor paralleling, control and protection.(3) Ratingsa. Rated voltage : 230 kVb. Rated insulation level-Lighting impulse withstand test voltage(1.2/50 micro sec.): 1050 kV (peak)Ghorasal 200 MW to 300 MW Gas Turbine Peaking Power Plant Project (Vol-2 of 3)57