Measurement Terminal Of Three-phase Asynchronous Motor

⑴ First, distinguish the two ends of each three-phase winding. Adjust the multimeter to the resistance range for measurement. Any coil of the same phase is connected without resistance, and any coil of different phases is not connected. Therefore, based on the multimeter, it can be distinguished that the two wire ends belong to the same phase winding lead out.
⑵ Identify the same end of the lead wires on both sides of the coil, adjust the pointer multimeter to the DC current range with the smallest range, connect the two wire ends of any phase winding to the meter, and then instantly touch the positive and negative terminals of the dry battery together with the two wire ends of the other phase winding. At the moment when the dry battery is connected to the coil, if the needle swings to the side greater than zero (i.e. clockwise swing), the positive terminal of the battery and the black probe of the multimeter are the same end, and vice versa.