How Does a 3-Phase Thyristor Power Regulator Use a Potentiometer to Control Voltage?

In this article, we will continue to explore another common wiring method for SCR power controllers: using a potentiometer as the input signal for controlling heating power. For detailed instructions on wiring with 4-20mA or DC voltage signals, please refer to our previous articles.

1. Main Circuit Wiring

The main power circuit connects the three-phase power supply to the heater through the SCR power controller. Begin by connecting the power source to the large terminal on the top of the SCR controller. Then, connect the output terminals at the bottom of the SCR controller to the heating elements. This establishes the flow of electrical power to the heater.

2. Control Signal – Potentiometer Wiring

In this configuration, a potentiometer serves as the control signal. The potentiometer is a variable resistor that adjusts the amount of power sent to the heating elements.

• Terminal 1 and Terminal 4: These terminals are connected to the fixed ends of the potentiometer.
• Terminal 3: This terminal is connected to the wiper (sliding contact) of the potentiometer, which adjusts the resistance as it moves.

As shown in the diagram, when the potentiometer’s slider moves to the left, the input impedance increases, which results in higher output power. Conversely, when the slider moves to the right, the impedance decreases, lowering the power output. This setup offers a simple, manual method for controlling the heating power by adjusting the potentiometer.

3. Power Supply to the SCR Controller

To power the SCR power controller, use a 220V AC supply. Connect the live wire to Terminal 20 and the neutral wire to Terminal 21. This will provide the necessary electrical supply for the SCR controller to operate effectively.

4. Program Settings

To configure the SCR controller to recognize the potentiometer input signal:

1. Refer to the Operation Interface to set A02 (Input Signal Selection) to AI2 (Analog Input 2). This ensures the controller accepts the potentiometer as an analog input signal.

This wiring method using a potentiometer offers a straightforward way to control the heating power. By manually adjusting the potentiometer, you can fine-tune the amount of power supplied to the heater, providing flexibility in various heating applications.

If you have any questions or need further assistance with setup, feel free to reach out to us.