The present invention relates to an electromagnetic contactor, and more particularly, to an electromagnetic contactor for star-delta driving, which is capable of rapidly and safely switching a connection of a 3-phase motor from a star connection to a delta connection and simplifying configurations of a connection circuit and an opening/closing device. According to the electromagnetic contactor for star-delta driving and a control device thereof of the present invention, the connection of the 3-phase motor can be switched rapidly and safely from the star connection to the delta connection, and the configuration of the connection circuit and a control circuit of a power supply thereof and a magnetic switch configuration can be simplified, and thus, there is an effect of saving space by reducing the size and weight of a product and reducing the numbers of power wirings and control circuit wirings. In addition, a magnetic switch between star and delta connections is interlocked by using a timer and an auxiliary contact, so as to improve the convenience of an operator and reduce construction time. In addition, because a timer base and the control device are ready-made in the form of manufactured goods, it is easy to use the products and there is very little risk of causing a misconnection in the control device. Thus, there are effects of improving the safety of a construction operator at a construction site and a general user, and improving driving components and circuit protection.

The present invention relates to an electromagnetic contactor, and more particularly, to an electromagnetic contactor for star-delta driving, which is capable of rapidly and safely switching a connection of a 3-phase motor from a star connection to a delta connection and simplifying configurations of a connection circuit and an opening/closing device. According to the electromagnetic contactor for star-delta driving and a control device thereof of the present invention, the connection of the 3-phase motor can be switched rapidly and safely from the star connection to the delta connection, and the configuration of the connection circuit and a control circuit of a power supply thereof and a magnetic switch configuration can be simplified, and thus, there is an effect of saving space by reducing the size and weight of a product and reducing the numbers of power wirings and control circuit wirings. In addition, a magnetic switch between star and delta connections is interlocked by using a timer and an auxiliary contact, so as to improve the convenience of an operator and reduce construction time. In addition, because a timer base and the control device are ready-made in the form of manufactured goods, it is easy to use the products and there is very little risk of causing a misconnection in the control device. Thus, there are effects of improving the safety of a construction operator at a construction site and a general user, and improving driving components and circuit protection.

An electric motor includes a plurality of phases and a switching device. The phases extend between respective terminals and are divided into a plurality of distinct groups, in particular at least a first group and a second group. The switching device is coupled to the first group and is operable to switch an electrical configuration thereof. The second group of phases is instead configured to maintain its electrical configuration unchanged during the switching of the electrical configuration of the first group.