How can a second "start" push button be added to a 3 wire motor control circuit?

Adding a second "start" push button in parallel with the first button is the correct approach for enhancing the operation of a three-wire motor control circuit. In this configuration, pressing either button will complete the circuit and energize the motor. This parallel setup allows for multiple points of activation, enabling the motor to be started from different locations, which is a common requirement in various industrial and operational settings.

In a three-wire control circuit, the parallel connection means that if one button is pressed, it closes the circuit, allowing current to flow and energizing the motor. This provides redundancy and flexibility in controlling the motor and improves accessibility for operators.

Connecting the second button in series with the first would not be effective because both buttons would need to be pressed simultaneously to start the motor, which could be impractical. Replacing the first button entirely would eliminate the original control option, leaving only one point of activation. Additionally, simply adding the button to the power supply line would not directly affect the control circuit's operation, as it would not serve the intended function of starting the motor.