Relays are used to control contacts of an electrical circuit due to a change of parameters or conditions in the same circuit or any other associated circuit. Contactors, on the other hand, are used to interrupt or establish connections in an electrical circuit repeatedly under different conditions.
What is the difference between a contactor and relay?
A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V.
Why do you need a contactor?
Why are Contactors Used? Contactors are used for high power applications. They allow a lower voltage and current to switch a much higher power circuit, so they are generally larger and more heavy-duty than control relays, enabling them to switch higher power loads on and off for many thousands of cycles (Figure 1).
What is relay function?
Relays control one electrical circuit by opening and closing contacts in another circuit. Relays are generally used to switch smaller currents in a control circuit and do not usually control power consuming devices except for small motors and Solenoids that draw low amps.
What is the difference between contactor and circuit breaker?
The main difference between electrical contactor and circuit breaker is, a contactor is an electrically controlled switch that makes contact to connect the load with the power supply whereas a circuit breaker is an electrical protective device that breaks contacts to disconnect the load from the power supply during a …
Why do we use a relay?
Relays are used where it is necessary to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal.
What is the purpose of a relay?
Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As relay diagrams show, when a relay contact is normally open (NO), there is an open contact when the relay is not energized.
What is the difference between contactor & control relay and contactor?
The key difference between control relays and contactors is the rating of current that they are designed to handle. Contactors are used for loads that have comparatively higher currents and higher system voltages. Here’s a brief definition of Contactor & Control Relay that will help you understand the key difference between the two:
What is the use of contact contact in a relay?
Contact of a relay can be used to connect or disconnect the coils of a contactor. Generally, a relay has several opening and closing contacts. Of course, the relay can also complete some special functions through proper connection, such as logic operation.
Why are there no spring-loaded contactors in control relays?
Since Control relays are designed for lower power, spring-loaded contacts are not so common. Arc Suppression: Due to the high loads contactors typically carry, they consist of arc suppression to quench the arc faster.
What is the function of auxiliary contacts in a contactor?
In contactors, auxiliary contacts are used to perform a different function that is linked to controlling the contactor. Auxiliary contacts for a contactor can be normally open or normally closed as per requirement. The safety features in relays and contactors are different as per the power of each device.
