AC120V Coil — What That Means for the Panel
The Mitsubishi Electric S-N21CX-AC120V is a magnetic contactor with a 120 V AC coil — that is the control voltage that pulls the main contacts in. If your control transformer or PLC output card delivers 120 VAC, this coil matches without an interposing relay. Rated for continuous duty at the coil voltage; the contactor stays closed as long as the 120 VAC signal is present. No DC hold-in module needed — the AC coil hums at line frequency, which is normal for this class.