loadingMM74直流灭磁开关
英国R.R.(Rolls-Royce)公司 型号：MM74 ，双断口 额定电压3200V 最大弧压6400V 额定电流6000A 最大开断电流50kA 带常闭放电触头。
MM74 MM74 High Speed DC Circuit Breaker
The MM74 high-speed DC circuit breaker has been
designed specifically to meet the system requirements of the DC substation switchgear for controlling the power supplies to heavy rail transit systems, and complies with requirements of ANSI C37.14-1992 and C37.16-1980. lt is also suited to the special applications of other fields as follows:-
Generator main field circuit breaker duty
Thyristor convertor-controlled motors Rolling units in steelworks Electrolytic plants Mine winders
This truck-type withdrawable circuit breaker has been developed from our long established panel and pedestal-mounted circuit breakers which have been in service since 1936.
Main Features ? ? ? ? ? Up to 12000A rating Fully interlocked Metalciad construction Top or bottom cable entry Over 50 years experience in DC switchgear
Rated voltage Rated normal currents
800, 1600, 3200V 4000, 6000, 8000, 12000A
Short circuit interruption rating 800V up to 250kA,1600V up to 150kA,3200V up to 50kA