Definitions for "Normally open"
Keywords:  damper, relay, switch, alarm, lawnmower
A term referring to a device such as an electrical switch, that is open in its normal position.
Designation which states that the contacts of a switch or relay are normally open or not connected. When activated the contacts close or become connected.
a circuit or switch in which the contacts are open during normal operation. Shorting or closing the circuit triggers an alarm signal.