Remote single wire control motor circuit

As shown in the figure, a circuit is used to control the motor from a long distance. In the figure, the local control button is a commonly seen start-stop circuit, except that two incandescent bulbs are connected in series in the control loop. An insulated wire is used to connect local and remote circuits. There are start button ST2 and stop button STP2 in different places. They use composite buttons and are properly connected to the phase lines L1 and L2 in the same power grid (note: L1 and L2 correspond to the local L1 and L2. The "same power grid" refers to the same distribution line). 380V of electric transformer). When the ST2 start button is pressed in a remote location, the L3 power supply in the remote location supplies power to the KM coil through a "single wire", KM pulls in, and the motor M starts running. Release ST2, and the local L3 phase power supply continues to power the KM coil through the two light bulbs. When parking in a different place, press the stop button STP2. Both ends of the foot coil are L2 phase power supply (same phase), so KM is released and motor M stops running. When the motor M is running normally, since the KM coil is connected in series with two 220V light bulbs, EL1 and EL2 are not only parking instructions, but also have a current limiting function. Generally speaking, a 40A AC contactor can be used with two 60W incandescent bulbs. For an AC contactor larger than 40A, the power of the bulb should be appropriately increased. EL1 and EL2 do not light up during normal operation. They only light up momentarily when STP2 is pressed to stop the car in a different place, which serves as a parking indicator in a different place.