What does an electric contactor do?
A contactor is an electrical device which is used for switching an electrical circuit on or off. It is considered to be a special type of relay.
Is a contactor AC or DC?
An AC contactor has a high starting current with a maximum operating frequency of 600 times/hour. That of a DC contactor is about 1200 times/hour. A DC contactor uses a magnetic quenching arc, while an AC contactor uses a grid arc as an extinguishing device.
Which is better contactor or relay?
For switching low power, when the additional safety features of a contactor are not necessary, a relay is typically the more economical choice.
What is the major difference between a contactor and a motor starter?
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. If there is no overload relay it is not a starter any longer. It’s back to being just a contactor.
What is the difference between contactor and 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 contactor is used in motor?
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).
Is a contactor coil wired like a load or a switch?
They are wired in circuits exactly like switches and they behave like switches because they are switches. Relay coils are loads; specifically, solenoids.
What is the difference between a contactor and a starter?
A contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. On the other hand, a starter employs overload relays to protect the motor from load surges by shutting it down to prevent overheating.
Why do I need a contactor?
What are the major reasons for replacing the contacts of a contactor?
Your contactor can fail electrically in one of three ways. The coil can become shorted, grounded, or open. Your technician will use a meter to determine the resistance crossing your contactor. If the readings are outside of a very narrow range; your contactor should be replaced.