2 Types Of Contactors and Protection Relays

Relays and contactors are responsible for performing the switching operation. Let us discuss each in detail. This article discusses what a relay is, what is a contactor, and its different types.


What Is A Relay?

Relays are switches that are used for the protection of equipment. It generally utilizes a control circuit and a power circuit. The control circuit helps regulate the flow of power and carries out basic switching operations by using small amounts of current to control, which is used to control a circuit with high amounts of current.

For small scale applications, the same task is carried out by fuses and similar contraptions for equipment protection. However, in large scale operations, relays are preferred because higher reliability is required.

Here are some common types of relays:

  • Time delay relays

Time delay relay is a type of electromechanical relay that is constructed to delay the armature motion on the coil. They are basically a kind of switches that are controlled by a circuit. The purpose of the time-delay relay is to start or stop the current from moving in coils and are designed to allow electrical circuits to prompt a time delay at a certain time.

  • Solid State and Protective relays

Solid State Relays are electronic switching devices that are designed to overcome the shortcomings of conventional relays such as reliability.

A protective relay helps the circuit breaker trip if it observes an abnormal or faulty condition. When it senses a fault, it gives the command to the circuit breaker to trip and isolate the malfunctioning element so as to prevent any damage. As soon the fault is fixed, the supply to the system is restored, and the system starts working in its normal state again.


What Is A Contactor?

A contactor is an electrical switch that can make or break the contact like a conventional switch. What makes it different from the traditional switch is the electromagnet that is integrated in order to hold the contacts. It functions similarly to the relay except that it can carry significant amounts of current than a conventional relay.

Additionally, it is essential to note that unlike relays, contactors cannot provide protection. Their only job is to make or break the contact. Here are some common types of contactors:

  • Manual Controller

Due to the potential dangers of using the knife blade switch, the electrical engineers came with another contactor device that offered a wide range of features that were lacking in a knife blade switch. This device was known as a manual controller. They are a non-exposed unit that is appropriately encased, therefore, safe to operate. They are also physically much smaller, which allows you to work with more current in even in tighter spaces.

Manual controllers are better than knife blade switch because they are replaced with double break contacts from single break contact. As the name suggests, double break contact can open a circuit in two places simultaneously. They divide the connection in such a way that it can form two unique sets of contacts.

The switch of the manual controller is attached to the controller physically. Once the manual controlled is activated by an operator, the power circuit is engaged, and it carries the electricity to the load.

  • Magnetic controller

These contactors do not need any human intervention as they operate electromechanically. This is an advanced design of a contactor that can be operated remotely. As a result, it can eliminate all risks involved in operating a contactor manually and putting the lives of personnel in potential risk. This is the most preferred type of contactor used in industrial applications.



Here are some of its most common applications:

  • Lighting control: Contactors provide central control of complex lighting installations found in commercial establishments.
  • Electric motor starter: Contactors are also used as a magnetic starter in electric motors. They include an essential component that provides power cut off and overload protection,

If you are looking for option sin relays and contactors, it is advised that you connect with a certified electrical professional to discuss your requirements. They can help you find the best solutions and also help with installations!


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