Most electricians know, three-phase motor three-phase stator windings of each phase winding has two lead the first. One is called the head-end, the other end is called the end. Provisions of the first end of the first phase winding which means that the end D1 D4; second phase windings of the first end which means that the end with the third phase windings of the first end of D3 and D6 to D5; D2. D1 to D6 mark the six lead the first terminal into the terminal box, terminal marked accordingly. The six ends of the three-phase stator winding three-phase stator windings may be connected in star or delta, star connection is the end of the three-phase windings connected in parallel, coming D4, D5, D6 three terminals copper Quick together, and the first end of the three-phase windings respectively connected to three-phase AC power the upcoming D1, D2, D5, respectively, access to the A, B, C phase power supply. While the the delta connection sucked first phase winding first end of D1 and the third phase winding terminal D6 is connected, and then connected in a phase supply; the first end of the second phase winding D2 with the terminal D1 of the first phase winding is connected to , then access to the second-phase power supply; third phase windings of the first end of D5 is connected with the end of the second phase winding D6, and then access the third-phase power supply. Terminal board terminals D1 and D6, D2 and D1, D5 and D6, respectively, connected by copper, then respectively connected three-phase power. An electric motor is connected in star or connected into a triangle, as specified by the manufacturer and can be found on the motor nameplate. A first end of the three-phase stator winding is the manufacturer prior Preferences good, never can optionally be reversed, but may be reversed with a first end of the three-phase windings, for example, the end of the three-phase winding D1, D5, D6, upside down as the headend , D1, D2, D5 as the end, but can not separate one phase winding terminal upside down, otherwise it will have a wiring error. Faulty wiring junction box, or the winding end made a mistake, ranging from motor does not start normally, long power caused by the start-up current is too large, the motor heat is serious, affect life expectancy, while burning motor windings, or short out power. Here's winding connection errors that are specific analysis.

    1 wrong should be connected as a star running asynchronous motor connected as the adverse consequences of running the triangle.

    Should be connected as a star-shaped movable line motor, the stator winding per phase withstand voltage (phase voltage) is the rated motor voltage (power supply line voltage) of the root of 1/3 times (i.e., 0.58 times). Misconnection run into a triangle, each phase stator winding is exposed to the phase voltage equal to the rated voltage of the motor, the stator the bear phase voltage of each phase winding rises to 1.732 times the voltage specified by the manufacturer. For example, the supply voltage is 380V, motor connected in star running winding voltage for 22 0V. If you pick the wrong run into a triangle, winding voltage will be increased to 380V. Winding phase voltage is increased, the core will be highly saturated the core flux magnetizing current will increase dramatically, up to several times of the rated motor current. Plus load current, such stator loop current, winding copper losses will increase dramatically, the motor stator windings due to severe overheating and burning.

    2 wrong will be connected into a triangle running asynchronous motor connected as star running adverse consequences.

    Mistakenly triangle-run motor connected into a star running, the phase voltage on the stator windings of each phase will fall to the original voltage root of 1/3 (i.e., 0.58 times). For example, the power supply voltage is 380V, delta connection, the stator winding voltage of 380V. The wrong connected into a star, per-phase stator winding phase voltage is reduced to 0.58 multiplied by 380 is equal to 220V. Therefore, the motor torque will be reduced to the rated torque (root 1/3) 2 = 1/3 times (0.33 times). At this time, the torque should still bring the operation of the rated load, in order to overcome the moment of resistance of the load requirements star connection and delta connection of the same size, so will force the stator circuit current increase in torque to try to The load balancing moment of resistance, resulting in overload fever, a long time will make the motor temperature rise over charge and Xu value. In the same time, also causes the motor power factor and efficiency decline. In another case, that is, when the load is less than 40% of the rated power (such as the big horse car), intends to delta connection method to the running of the star connection is good. Because when the load is light (generally less than 40% of rated power), does not require a large load current torque to overcome the load resistance moment. But the low voltage winding, the magnetizing current is reduced more, and the total stator current or decreasing the motor power factor and efficiency are improved, the temperature rise will also decline.