What is the Use of Different Types of Relays: Contactors, Electric and Protection Relays?

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Relays can be defined as switches whose primary function is to close and open the circuits electronically as well as electromechanically. Relays essentially regulate the opening and closing of the circuit contacts of an electronic circuit. According to the dictionary, a relay refers to the action of passing something from one thing to another. This literal meaning can be applied to this device since the signal received from one side of the device regulates the switching operation on the other side.

The different types of relays are explained below:


When a relay is employed in order to switch a significant amount of electrical power through its contacts, it is assigned a specific name: contactor relay. Contactors generally consist of multiple contacts and those contacts are (but not always) normally-open to ensure that power to the load is shut off when the coil is in the de-energized state. Perhaps the most popular industrial use of contactors is the regulation of electric motors.

Electric Relay 

An electric relay is an electromagnetically regulated electrical switch. A small current is employed to create a magnetic field in a coil within a magnetic core which is then consequently used to operate a switch that can control a much larger current. In this way, an electromechanical relay or electrical relay can make use of a small current to switch a much larger current and ensure that both circuits are electrically isolated from each other.

Electrical relays come in different sizes and types based on their function, while they function and perform on the same fundamental concept.

Protection Relay 

On the other hand, protection relays can be explained as a smart device that receives input, compares them to set points, and provides output. Inputs can exist in the form of current, voltage, resistance, or temperature while outputs can incorporate visual feedback in the form of indicator lights and/or alphanumeric display, communications, control warnings, alarms, and turning the power off and on.

It can be stated that the concept of relays is critical in electrical power systems and in managing power distribution, whether in homes, commercial, or industrial settings. Especially with big brands like #SchneiderElectric who is a leading player in the field of electric protection, home and industrial automation, and distribution management systems.