A magnetic contactor is just a switch. So don’t let the term “magnetic contactor” scare you and start thinking it is some space age electrical gadget. Magnetic contactors has been around for decades. The most common magnetic contactor which we all would have seen is the Air Con starter that we see in our house. It is the simplest form of a magnectic contactor.
How does a Magnetic Contactor Work“
As the name suggest, the magnetic contactor works by means of a magnet. Not the ordinary magnets we see but an electro-magnet. An electro magnet is something that can become a magnet when it is energised with current. When current is switch off, it becomes an ordinary piece of metal with no magnetic properties.
The magnetic contactor is a switch that is activated by the magnet. When current passes through the coil, it energises the it and the piece of metal becomes a magnet which in turn attracts the contacts point and pull the contacts together, allowing current to pass through.
Usage of Magnetic Contactors
Magnetic contactors are primarily used to start electrical motors because it can prevent damage to the motors in event the motor gets jammed and overloads. This is achieved by way of passing the current through an overload protection coil before energising the magnet. If the motor gets jammed and overloads the circuit, the overload coil will automatically cut of the current thereby de-energising the coil and thus opening the contacts.
Heavy industries relies heavily on magnetic contactors to start and keep their machines running smoothly. These contactors are very versatile. Many kinds of starter circuits can be designed by electrical engineers to automate the running of machines in various usages. Machines can be started and shut down automatically and safely with a well designed starter circuit.