A control relay is an electromagnetic device or switch that is controlled by an electrical current. These locally or remotely controlled switches are used in a wide variety of equipment.
Essentially, control relays open and close switches, allowing current to pass through a conducting coil, with the coil avoiding direct contact with the switch. Therefore, the main function of a control relay is to control the power flow in circuits.
Applications of control relays
Control relays can be found in numerous applications such as:
Power supply systems
What is the difference between control relays and contactors?
Although control relays and contactors are both electrically operated switches, there are some important differences between them. The main difference between these two devices is the rating of current that they can handle. Contactors are used for loads with comparatively higher currents and system voltages.
Control relays are also comparatively smaller than contactors and are more commonly used in control circuits (single-phase circuits), whereas contactors are commonly built for switching 3-phase loads.
Whereas control relays are usually rated 250V, contactors are rated for up to 1000V.