Refers to switch contacts that are closed in the normal switch state or position (unactuated). A pressure change opens the contacts.
The condition of a circuit or switch that is in a no-fault state. The circuit is complete and the current is able to flow. A break in the circuit triggers an alarm.
A term that refers to a switch which is closed and connected in its normal position.
The state of the output or switch is ON with no external influence.
Refers to the electrical state in which a switch may rest. Its contacts are held together or closed so that current is allowed to flow through its contacts.
Designation which states that the contacts of a switch or relay are closed or connected when at rest (i.e. no energy applied). When activated, the contacts open or separate. Symbolized by NC.
A switch, relay, valve or damper that is closed when the power is not being applied.
In electronics, a normally closed switch is one that normally allows current to flow and which prevents current flow when it is perturbed.
