ELECTRICAL APPARATUS INCLUDING INTERLOCKING CIRCUIT FOR SHORT-TIME DELAY AND LONG-TIME DELAY TRIPPING

摘要

47,372ELECTRICAL APPARATUS INCLUDINGINTERLOCKING CIRCUIT FOR SHORT-TIMEDELAY AND LONG-TIME DELAY TRIPPINGABSTRACT OF THE DISCLOSUREA circuit breaker of the type having short delayand long delay tripping modules. Separate signals areprovided as external outputs from the latter modules.Furthermore, inputs are provided to the latter modules fordisabling the normal operation thereof. The above-mentionedbreaker also includes an instantaneous tripping circuit. Ifthe amount of overload current is sufficiently high, aninstantaneous tripping operation takes place. If the over-load current is relatively lower than that which wouldnecessitate instantaneous tripping, short delay or longdelay tripping will take place. If the current then con-tinues to increase to a sufficiently high value, the circuitbreaker will operate through the instantaneous trippingcircuit. One of the above-mentioned circuit breaker appar-atus can be interconnected with others so that one circuitbreaker in an electrical line to be protected will open andprovide output signals which will prevent the short delayand long delay of other circuit breakers in the system fromoperating thus saving some of the protected system fromshut-down.