When a limit control closes its contacts due to a rise in temperature, it is referred to as?

When a limit control closes its contacts due to a rise in temperature, it is referred to as reverse acting. In reverse acting systems, the control responds inversely to the variable it measures. Thus, as the temperature rises and surpasses a set threshold, the limit control will close its contacts to stop the operation of the heating equipment, effectively preventing overheating and ensuring safety.

In contrast, normal acting controls would open or close their contacts in response to a decrease in temperature, directly aligning with the rise or fall of the temperature measured. Fail-safe systems are designed to default to a safe state when power is lost or fails, which does not specifically address the temperature rise scenario. Direct acting typically refers to controls that respond directly and immediately to changes in the variable being measured, but it doesn't fit the description of a limit control that closes due to high temperature.