1. The Contractor shall design, manufacture and test each 161 kV SF6 dead tank circuit breaker for load and fault current interruption in substation bus applications in accordance with this section and applicable sections of the latest revisions of the following, unless otherwise specified: American National Standards Institute (ANSI) Institute of Electrical and Electronics Engineers (IEEE) National Electrical Manufacturers Association (NEMA) National Electrical Code (NEC) National Electrical Safety Code (NESC) American Society for Testing and Materials (ASTM) 2. The Contractor shall furnish six (6) 161 kV SF6 circuit breakers, each with 18 current transformers, as described in this technical specification. The breaker shall meet and or exceed the technical specifications detail in this section. If there are conflicts among the above, the Contractor will determine which is applicable, and submit in writing to the Engineer for approval, the manner in which the conflict is to be resolved. Each breaker shall be electrically and mechanically trip free, and shall comply with or exceed the following design criteria and ratings: Type: SF6, Dead Tank, Frame Mounted, Outdoor, 3Ø, Single Throw Nominal line-to-line voltage: 161kV, 60Hz System connections: Solidly Grounded Wye Maximum Wind Velocity: 125 mph UBC Seismic Zone: 2A Radial Ice Loading: 13 mm Ambient Temperature: -22˚F to 140˚F Elevation: 1500’ AMSL Rated Maximum Voltage: 169 kV Rated Continuous Current: 2000A Insulation BIL Withstand Test Voltage (Breaker and Bushings): - Low frequency (60 Hz dry for 1 minute): 365 kV - Full wave impulse (1.2 X 50-microsecond waveform): 750 kV - Chopped Wave Voltage Withstand (2µsec): 968 kV - Chopped Wave Voltage Withstand (3µsec): 862 kV Rated short-circuit current at rated maximum voltage: 40 kA 3 second, short time current carrying capability: 40 kA Maximum symmetrical interrupting capability: 40 kA 3 Phase Interrupting Rating: 11,000 MVA Closing and latching capabilities (rms): 64kA Rated interrupting time (Max): 3 Cycles Rated reclosing time (Max): 20 Cycles Reclosing duty cycle (no derating): OCO-15S-CO A.C. Accessory Voltage (1-phase, 3 wire, 60Hz): 120/240 volts D.C. control Voltage: 125 volts Insulating and interrupting media: SF6 Single pressure interrupter not to exceed: 100 psi @ 70˚F 3. The breakers shall be capable of withstanding 1.5 times the phase to ground voltage with the gas pressure equal to 0 psi and with the breaker in the open or closed position. The design shall be such that under impulse voltage, flashover occurs outside of the tank before flashover occurs within the breaker.
