Here's the answer
These are axillary points of megnetic contactor NC for normally close and NO for normally open. These points are used for control circuits. In addition to this, NC terminal used for normally close contact and NO terminal used for normally open contact.It's auxiliary Dry contact used for bypass line or emergency signals activities. Finally, This is the state of the auxiliary contacts of a magnetic contractor before being ernergized; NC - closed and NO - open. When the power supplies the coil of con, the normal close points become open this mean cut the power for control
And the normal open points becomes close and supply the control circle.
