PURPOSE: To provide a ventilating equipment for a tunnel, wherein a manually operable second switch is provided in parallel with a first switch which can be operated at regular intervals of time so that a ventilating fan can be automatically operated at regular continuous intervals of time, and further the ventilating fan can be operated at any time if desired to increase a factor of safety.
CONSTITUTION: When an electromagnetic circuit breaker MCB is closed a timer 2 is started. When contacts of the timer 2 are closed an auxiliary relay X2 is energized, a first switching means X2a is closed, and a relay 52X becomes in an energized condition. Thus an electromagnetic contactor 52 is caused to close and the operation of a ventilating fan is initiated. After a certain period has passed the contactors 2a of the timer 2 are opened to stop the operation of the ventilating fan Br. These actions are repeated to ventilate a tunnel. When the contactors 2a of the timer are opened, and if a push-button switch BS1 or BS2 is pushed, a second switching means X1a is closed, and the ventilating fan Br becomes in an operating condition. If the release of the push-button switch is neglected a third switching means X2b serves to permit the ventilating fan to get back to its normal operation.
INOUE KAZUYUKI
TSUNODA AKIRA
HITACHI LTD