What this coil does in the panel
The ENW21521 is a closing coil for the EasyPact NW range of air circuit breakers. It pulls the breaker main contacts closed when you energize the control circuit. The coil holds at 4.5 W / 4.5 VA once sealed. The electrically operated, maintained control signal type means the coil stays energized to keep the breaker closed — drop the control voltage and the breaker trips (or the undervoltage release, if fitted, takes over). That's the standard scheme for remote-operated switchgear where you want loss-of-control to open the breaker.