Voltage phase sequence monitoring device for three-phase alternating-current motor

A voltage phase sequence monitoring device for a three-phase alternating-current motor comprises a live wire L1, a live wire L2, a live wire L3 and a zero wire N of an inlet cable connected to an input end of an inlet connection terminal. An output end of the inlet connection terminal is connected with an input end of a first air switch, output ends of the first air switch and a second air switch are jointly connected to one end of a fuse, the other end of the fuse is connected with an input end of a phase sequence transfer switch, an output end of the phase sequence transfer switch is respectively connected with a third air switch and an outlet connection terminal, an output end of the third air switch is connected with an input end of a connection terminal of a speed reducing motor, an output end of the connection terminal of the speed reducing motor is connected with the speed reducing motor, the other end of the outlet connection terminal is connected with an outlet cable, one end of a handle switch is co