What is the primary function of a differential relay?

The primary function of a differential relay is to check whether all the electrical current entering a system exits it, which is essential for protecting electrical equipment and ensuring system integrity. When used in the context of water treatment facilities or other industrial applications, a differential relay monitors the difference in current between two points. If there is a discrepancy, it indicates a potential fault, such as a short circuit or equipment failure. This capability allows operators to quickly identify and respond to issues that could lead to equipment damage or unsafe operating conditions.

In contrast to options like monitoring water temperature or assessing flow rates, which focus on operational parameters of the water treatment process, the role of a differential relay is more about the safety and reliability of the electrical systems that power various equipment, including pumps. Additionally, while controlling pump motor speeds is relevant in the context of system efficiency and operational control, it does not pertain to the core function of a differential relay, which is centered on current measurement and fault detection.