What status should the controls have when the control circuit is de-energized?

For the question regarding the status of controls when the control circuit is de-energized, the correct answer is that they shall be inoperative. This is important for safety and operational integrity. When a control circuit is de-energized, it is essential that the controls are not able to operate, preventing any unintended or hazardous operation of the equipment.

This requirement is based on ensuring that systems can be safely serviced and maintained without the risk of accidental activation. If controls were to operate freely or remain at their last setting while de-energized, it could lead to confusion or unintentional activation once power is restored. Similarly, defaulting to maximum output would present a significant hazard, potentially resulting in equipment damage or safety risks. Therefore, the correct response emphasizes the need for controls to be completely inoperative during a de-energized state, thereby enhancing safety protocols in mechanical systems.