What is contactor?
A contactor is a device that is for making and breaking an electrical power circuit.
A contactor is a electrical device which is used an switching an electrical circuit on or off.
For example we usually use a contactor for turning on and off an electrical motor
Now you may ask why do we need to use a contactor
Can't we connect the motor directly to the PLC. Well the the short answer is no.why? Because you don't want to connect a high voltage electric motor to your Shiny expansive to PLC directly.
this will damage the PLC cards if there are any electric surges on the motor side.
So what we do instead we use contactor to connect the PLC to the the motor indirectly and safely what do I mean by indirectly you ask well all contactors have low voltage coil.we connect the PLC output to this coil. this coil usually workswith a 24 volt Dc signal. Once the coil energized ,an electromagnetic field will be created. this electromagnetic field then causes the 3 contacts here to closed and that's how the 3 phase power will reach the motor and can turn it on.
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