Commutation circuit controlled by KO-3 three-phase switch for single-phase motor

As shown in the figure, the ordinary three-phase motor reversing switch type KO-3 is modified and can be used to control the forward and reverse rotation of a single-phase capacitor starter motor. During modification, use one wire to connect terminals 1 and 5, use two wires to connect 4 and 6 to the power supply respectively; lead 4 wires from terminals 5, 8, 9 and 6 respectively and connect them to the capacitor starting single-phase The terminal box of the motor is V(D2), W(D3), V"(D5), W"(D6). It should be noted that the two wires 5 and 6 must be connected to the terminals V(D2) and W"(D6) of the motor. That is, on the main winding coil LR, 8 and 9 are connected to the auxiliary winding LA: the U (D1) and U" (D4) terminals are connected to the terminals of the starting capacitor C; the motor centrifugal switch S is connected to W and U of the terminal box "(D3, D4). Operation method: Push the KO-3 switch handle to "positive", S1 is turned on, and the motor rotates forward; when it is pulled back to the middle position "stop", the motor is powered off; then pull it to " When "reverse", the motor reverses; when pushed back to "stop", the motor stops. It is worth mentioning that when the motor switches from one operating state to another (such as forward rotation to reverse rotation), it must Let the motor stop before starting again, otherwise the starting current required to overcome the rotational inertia of the motor will be extremely large, which is detrimental to both the motor and the switch.