Is a relay and contactor the same thing?

Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions. Control Relay is more commonly used in control circuits which are single phase circuits. Contactors are typically built for switching 3-phase load.

Why use a relay instead of a contactor?

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.

Can a contactor be used as a switching relay?

Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. It is used for power switching. A relay consists of at least two contacts and an excitation coil. These contacts may be normally open or normally closed.

What is the difference between a relay contactor and a starter?

It’s simple. A contactor is really just an overgrown relay. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. A motor starter is simply a contactor PLUS an overload relay and is rated by motor HP or amperage.

What is the difference between circuit breaker and contactor?

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 …

What are the three major parts of a contactor or relay?

In this section the term contactor is generally used but reference could also be made to relay contacts and power contacts, all operated from the same device. A contactor consists of three basic parts: the operating coil, the associated magnetic circuit and the contacts that are actuated by the coil.

Why are contactors better than switches?

A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 230-volt motor switch. Unlike relays, contactors are designed with features to control and suppress the arc produced when interrupting heavy motor currents.

Can a contactor be repaired?

Coils can be replaced but are not repairable. While the coil in a contactor can be replaced, it is usually not worth the effort. They can often be hard to find to fit the contactor you have. It takes more effort to take the contactor off the unit then dismantle the coil than it does to simply replace the contactor.

What is a chattering contactor?

Contact chatter is extended contact bounce that is not an inherent part of the relay. Contact chatter usually occurs because of either shock or vibration to the relay or an improper relay control signal.

What is the difference between a contactor and a relay?

Contactor vs Relay Applications. Contactors are typically built for and used in 3-phase applications where a relay is more commonly used in single phase applications. 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.

What are solenoids, contactors and electromechanical relays?

For some the words solenoid and relay conjure visions of an ancient electromechanical world now replaced by all-electronic devices, smart motors, and more. That almost makes sense, as these two components in various forms have been with us for over 150 years.

What are the interlocking contacts on a relay?

The main contact can have interlocking contacts to indicate the opening and closing of the main contact. Relays are generally used in electrical control circuits to expand the contact capacity of miniature or small relays to drive larger loads.

Why are contactors used in high load situations?

Because contactors are typically carrying high loads, they often contain additional safety features like spring-loaded contacts to help ensure the circuit is broken when de-energized. This is important because in high load situations contacts can weld themselves together.