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A contactor is one of the most common components used in electrical control systems. It allows us to safely turn large electrical equipment, such as motors, on and off without directly interacting with high levels of electricity.
What Is a Contactor?
A contactor is a switch that we use to turn on and off big electrical equipment like a big motor.
For small things like a lamp, we can use a simple switch, but for bigger things we usually need to use a contactor instead.
We can press a simple switch by hand and turn on a lamp, but we cannot do the same thing with a contactor.
Why?
Because it is not safe to do that.
Contactors are usually used in circuits with a higher level of electricity, and that is not safe for us to interact with directly. That is why we do it indirectly.
How Does a Contactor Work?
Inside each contactor, there is a coil.
A coil is just a long wire that is wrapped in loops. Now, if you take this coil and connect it to a 24-volt power supply, it turns into a magnet.
Now, if you put this magnet close to the contacts, it pulls them in and closes the circuit. So now we can indirectly and safely interact with the contactor.
Inside each contactor, there are three main contacts and a coil.
We connect a 24-volt power supply to the coil, and the coil turns into a magnet. The magnet pulls the contacts and closes the circuit, so electricity can pass through and turn the motor on.
Now, if we cut off the 24-volt power, the magnet turns back into a coil and the contacts open. When this happens, the circuit opens and the motor stops.
Summary
A contactor is used to safely turn large electrical equipment on and off. Instead of touching the high-power circuit directly, we use a lower voltage, such as 24 volts, to energize the coil inside the contactor.
When the coil becomes a magnet, it pulls the contacts closed and allows electricity to flow to the motor. When the coil loses power, the contacts open and the motor stops.
So that is simply how a contactor works.
