The NC7 series AC contactor (hereinafter referred to as
“contractor”) is mainly used in the circuit with an alternating
 current of 50Hz (or 60Hz), rated operational voltage up to
 690V, and rated operational current up to 620A under the
 usage category of AC-3/400V; this contact is mainly used for
 remotely closing and breaking circuits, and can be combined
 with an appropriate thermal overload relay to form a
 electromagnetic starter so as to protect the circuits likely
 to be overloaded in operation; the contact is well suited for
 frequently starting and controlling AC motors.

• NC7 AC Contactor