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: �20μΩ 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 Items Value Rated voltage 12KV Rated current 1250A Rated frequency 50Hz Rated power frequency withstand voltage 42kV Rated lightning impulse withstand voltage 75kV 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 20000 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 �20μΩ Storage life 20 years Limiting abrasion of contacts 3mm  Mechanical requiements of vacuum circuit breaker Items Value 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
