Normally open. A type of switch, relay, or contactor contact that does not conduct electricity until it is actuated or energized. When the coil is powered or the button is pressed, the contacts close to complete the circuit. It is the standard configuration for start buttons and interlocks that require active confirmation to proceed.
Heard on the job
Wire the start sequence through the NO contacts on the pressure switch so it only runs when we have air.
Also heard as
- normally open