Discrimination method of stator winding end and end of three-phase asynchronous motor
When the wiring board of the motor is damaged and the six terminals of the stator winding are unclear, it is not allowed to connect blindly, so as not to cause internal faults of the motor. Therefore, it is necessary to distinguish the head and tail ends of the six terminals before connecting.
1) use 36V AC power supply and bulb to distinguish the head and tail ends.
The wiring mode for discrimination is as shown in the figure, and the discrimination steps are as follows:
A. Find out the two ends of each phase of the three-phase winding with the resistance of a shaking table or multimeter.
B. First, randomly number the ends of the three-phase winding as U1 and U2, V1 and V2, W1 and W2 respectively. And connect V1 and U2 to form a series connection of two-phase windings.
C. Connect a light bulb to the ends of c．U1 and V2.
D. Connect 36V AC power to the two terminals d．W1 and W2. If the light bulb lights up, it means that the numbers of terminals U1, U2, V1 and V2 are correct. If the light bulb is not on, just switch the numbers of any two wires in U1, U2 or V1, V2.
E, judging the ends of W1 and W2 according to the above method.
2) use multimeter or microammeter to distinguish the head and tail ends.
(1) Method 1
A. First, use the resistance file of a shaking table or multimeter to find out the two ends of each phase of the three-phase winding respectively.
B. Assume that the windings of each phase are numbered as U1 and U2, V1 and V2, W1 and W2.
C. Connect the wires as shown, and turn the motor rotor by hand. If the pointer of multimeter (micro-ampere gear) does not move, it proves that the assumed number is correct; If the pointer is deflected, it means that the assumed numbers at the beginning and end of one phase are incorrect. It should be adjusted and re-measured one by one until it is correct.
(2) Method 2
A. First distinguish the two ends of each phase of a three-phase winding, and assume that the winding terminals of each phase are U1 and U2, V1 and V2, W1 and W2.
B. Watch the direction of the pointer swing of the multimeter (micro-ampere gear), and close the switch instantly. If the pointer swings to the side greater than zero, the terminal connected to the positive electrode of the battery and the terminal connected to the negative electrode of the multimeter are both the head end or the tail end; If the pointer swings in the opposite direction, the terminal connected to the positive electrode of the battery is the same as the terminal connected to the positive electrode of the multimeter.
C, connecting the battery and the switch to two terminals of another phase, and testing, so that the head and tail terminals of each phase can be correctly distinguished.
