Is a control relay designed to switch components on and off only when it receives a manual input?

A control relay is not limited to switching components on and off solely in response to manual input; it can operate automatically based on various inputs or conditions. Control relays are designed to respond to a range of triggering signals, which can be electrical, mechanical, or even sensor-based, depending on the application. For example, a control relay may activate based on temperature changes, pressure levels, or other automation signals in a control system. This capability allows for greater flexibility and functionality in automated processes. While some relays may be used exclusively with manual controls in specific applications, many are designed for automatic operation, making the assertion that they only respond to manual input inaccurate.