Three-wire control circuits are typically used for what purpose?

Three-wire control circuits are primarily utilized for start/stop pushbutton stations, which are common in motor control applications. These circuits typically consist of three wires: one for the power supply, one for a momentary pushbutton switch that initiates or halts operation, and one for the return path that completes the circuit.

The design allows for remote control of motor operations, making it possible to start or stop a motor from a distance. When the start button is pressed, it completes the circuit, energizing the coil of a contactor and starting the motor. Releasing the button does not stop the motor due to the holding contacts that maintain the circuit until the stop button is pressed. This functionality is crucial in various industrial settings where safety and efficiency are priorities, as it enables operators to control machine operations intuitively and effectively.