| 摘要 |
PURPOSE:To prevent the building from being damaged by a method wherein a charging blower or an exhaust blower is brought automatically to stoppage before excess positive or negative ventilating pressure in the building exceeds the allowable ventilating pressure value of the building in the ventilating equipment of an atomic power plant or the like. CONSTITUTION:In case that blowers are brought into independent operation due to some causes or misoperations during automatic or manual operation, and when the positive or negative ventilating pressure in the building of an atomic power plant or the like reaches the set value of a differential pressure switch 15, an output contact 16, which is actuated by excess positive ventilating pressure, or an output contact 17, which is actuated by excess negative ventilating pressure is closed in order to output a stop signal relay 18 into operation for self-holding. The contact 19a of said stop signals relay 18 is transmitted to circuit breakers 21 and 22, resulting in closing an (a) contact 19a and opening a (b) contact 19b in order to automatically stop the blowers 3 and 4, which are operated independently. |
