Manual Call Point is a manually operated switches which purpose is to provide means of manual initiation of fire alarm by operator. Manual Call Point is simple electrical switch that requires manual activation and set in open position during normal operation to prevent spurious alarm. There are several operation mechanisms of manual call point:
Break Glass Type
A box with a breakable window at the front. Inside there is a switch, usually held in the open position by means of a spring-steel arm positioned against the window. When the window is broken the spring switch mechanism is released and the contacts close, initiating an alarm.
Lift Flap and Push
This type uses a guarded pushbutton. Some types require an operator to lift a spring-loaded cover to access a pushbutton (or pull-button). This action closes the contact, initiating an alarm.