HOLT Electricians Practice Exam

Where must a control circuit transformer be connected if it is located in the controller enclosure?

1. Input side

2. Output side

3. Load side

4. Neutral side

The correct answer is: Load side

The correct choice is based on the understanding of transformer connections within control circuits. A control circuit transformer is typically connected on the load side when it resides within the controller enclosure. Connecting the transformer to the load side ensures that it contributes directly to the operation of the control circuit by providing a step-down voltage to the devices that need lower voltage control signals, such as relays, sensors, or control logic. This configuration allows for better operation and reliability of the control system by ensuring that the control components receive the appropriate voltage level required for their function while isolating them from the higher voltage components on the input side. Using the transformer in this manner also offers advantages such as enhanced safety and reduced risk of electrical shock, as operators and maintenance personnel are more likely to interact with the control circuit rather than the primary voltage side. Overall, placing the transformer on the load side aligns with industry best practices for control system design, ensuring efficient and safe operation.