(1) Three-phaseasynchronousThe motor does not need to be connected to the neutral line, because the sum of the three-phase electric vectors at any time is zero.Even if the neutral line is connected, there is no current, so the three-phase motor has no neutral line, so there is no need to connect the neutral line.

(2) The reason why the three-phase motor has no neutral line is because the voltage between the neutral line and the phase line is 220V, andThree-phaseasynchronouselectric motorThe required voltage is 380V, so the three-phase motor should be connected to the three-phase power line, and there is no neutral line.

(3) The function of shell grounding is to prevent some phase insulation from being damaged and the shell is electrified and causing electric shock accidents.

(4) But it is better not to use the same ground wire of the inverter and the ground wire of the motor, because the ground wire may age and break for a long time in some factory environments with heavy moisture.

(5) In the TN-S system, the metal shell of electrical equipment such as motors should be grounded, that is, PE wire!A power supply system cannot be grounded and connected to the neutral line! At the end of the TN-S system, the voltage difference between the neutral wire and the ground wire may reach ten volts or even higher due to the three-phase unbalance and the influence of the third harmonic.

(6)Three-phase asynchronous motorThe wiring methods are: delta connection and star connection.△Means the delta connection method, which is to short-circuit the upper and lower terminals in the junction box to obtain three pairs of electrodes, and then connect the three-phase live wires respectively. Y stands for star connection, which means that the upper three terminals in the junction box are short-circuited, and the lower three terminals are connected to live wires respectively.