Model No.: TD 12kv 1250A 25KA (JUC613) vacuum interrupter for VCB Main technical parameters Rated voltage: 12 KV Rated current: 1250A Rated power frequency withstand voltage: 42 KV Rated lightning impulse withstand voltage: 75 KV Rated short circuit breaking current: 25KA Rated short circuit making current(peak value): 63KA Breaking operations under rated short circuit breaking current: 30 times Rated short time withstand current: 25KA Rated withstand current(peak value): 63KA Rated duration of short circuit: 4S Mechanical life: 20,000 times Closing force due to bellows and atmosphere: 120±50N Force required to hold contacts opening at full stroke: 190±50N Circuit resistance at lowest rated contacts force Storage life: 20 years Limiting abrasion of contacts: 3 mm Mechanical requiements of vacuum circuit breaker Clearance between opening contacts: 11±1mm Average opening speed(Contacts closing position~75% contacts opening distance): 1.1±0.2 m/s Average closing speed(30% contacts opening distance~contacts closing position): 0.6±0.2 m/s Rated contacts pressure: 2000±200N Contacts bouncing duration at closing operation: �2ms Contacts re-bouncing clearance at opening operation: �2mm Synchronism of three phases: �1ms