What is the difference between NO and NC for different switches?
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What do NO and NC mean for temperature, pressure, and level switches? For example, with pressure switches, NC means that the switch is not installed, which is the condition when the pressure is 0? Is it still the normal pressure level when the pressure has not reached the set value of the switch?
Normal open – NO: Under normal circumstances, it is in an open state; that is, the contacts are open when the coil is not powered, or when there is no movement. Such contacts are referred to as normal open contacts. Normal closed – NC (normal close): It is in a closed state under normal circumstances; that is, it remains closed when the coil is not powered, or when the contacts are closed in a static state (with no movement). Such contacts are called normally closed. Simply put: Normally open contact: a contact that closes when the device \"operates\", and is open in its natural state (normal condition); Normally closed contact: a contact that opens when the device \"operates\", and is closed in its natural state (normal condition). For a pressure switch, NC means that the switch is closed when the pressure has not reached the set point.