What does mean no nc relay?

"Mean no NC relay" typically refers to the absence of a normally closed (NC) relay in a circuit or system. In relay terminology, a normally closed relay allows current to pass through when the relay is not energized, whereas a normally open (NO) relay does not conduct until it is activated. Thus, "mean no NC relay" suggests that the system only uses normally open relays, which can impact how the circuit operates, particularly in controlling devices or signals.