Outdoor vacuum circuit-breakers of series BP35NSM fitted with organosilicon and air insulation of poles (without transformer oil) and spring drive are designed for switching HV electrical circuits in normal and emergency modes in three-phase alternating current networks with ungrounded or partially grounded neutral of 50 (60) Hz frequency and 35 kV rated voltage.
Circuit-breakers series BP35NSM with spring drive are used in 35 kV outdoor switchgears of modular transformer substations types KTPBR-220/35/10(6), KTPBR-150/35/10(6), KTPBR-110/35/10(6), KTPBR-М-35/10(6) and blocks of complete switchgears in railway traction substations as well as for extension of existing substations and replacement of outdated air and oil circuit-breakers at them.
Specifications:
- Rated voltage (kV): 35
- Rated current (A): 1600
- Rated breaking capacity (kA): 20
- Peak withstand current (kA): 52
- Mechanical lifetime: 30,000 CO cycles
- Electrical lifetime at rated currents: 30000 CO cycles
- Electrical lifetime at rated breaking currents: 55 CO cycles
Design
Circuit-breakers series BP35NSM consist of four main parts, namely:
- a pole consisting of insulating envelopes with organosilicon insulation and vacuum interrupters
- a frame housing shafts, adjusted tie-rods, opening spring and buffer
- a cubicle with spring drive
- a supporting frame with four mounting holes
The pole of BP35NSM circuit-breaker consists of vacuum interrupter, supporting covers, insulating tie-rod, upper and lower terminals, fasteners and parts for sealing the pole. Upper and lower parts of the pole are made of fibreglass pipe externally covered with finned organosilicon insulation.