Most industrial machinery comes with a fail-safe measure to guard against fluctuations in the power supply. This is essential as even if one of these machines break down, the entire sequence of activities can fall, causing a temporary break in operations. This is further compounded by the over-taxed electrical systems that our cities depend upon.
As our usage rises, these systems tend to break down or glitch from time to time. Certain mechanisms like circuit breakers help sever the connection between the main source of power and the machine.
Magnetic contactors work on a similar design as the circuit breaker but differ in one specific way. They do not cut the connection but act as a go-between for the direct power source and the electrical motors. By doing this, they can stabilize any fluctuations in the power supply. This way, they can protect the equipment and balance out the voltage spikes and dips. These detachable instruments also ensure that the motor is completely without power during repairs.
How Does It Work?
Magnetic contactors are typically a box-like instrument that varies in size, depending on the machine they have to be attached to. Their exterior is made of heat resistant material which is non-conductive. Inside, one contact leads to an electromagnetic coil while the other takes you to a soft iron core that is kept separated from the coil by a spring.
They follow basic electromagnetic principles. A simple electromagnet is created by winding a wire around a soft iron core, which is then connected to a DC voltage source. When current flows through the wire, it temporarily magnetizes the coil. On the other hand, when the DC voltage course is removed from the coil, the current halts, and the coil is back to its nonmagnetic state.
When electricity passes through the contactors, the electromagnet inside it generates a magnetic field, which creates an electric arc. Thus, electricity passes through the contactor’s parent device.
When there is no electrical current, the spring inside the device moves away from the coil and, in doing so, breaks the connection. Magnetic contactors have three main components that come in touch with the current. This includes power contacts, contact springs, and auxiliary contacts.
What Are The Advantages?
The contactors are detachable and are very useful during repairs. When the magnetic contactor is removed from the motor, there is almost no chance of live-current passing through the motor. This ensures the safety of the maintenance crew and confirms that the motor is repaired with minimal risk. These kinds of contactors are usually used for loads that are greater than 10A.
Which One To Choose?
Magnetic contactors are very specific to the machine attached to and have to be chosen with great care. One of the criteria is to select a contactor that is suitable for the motor’s inrush current. This helps you ensure that the contactor is up to the task and is able to bear the flow of electrical current. The second criterion encompasses the voltage of the power supply.
Since the contactors are designed to be the connection between the motor and the main power source, it is essential that you pick the one that is best suited for the task. Contactors vary in size and can range from one that fits into your hand to longer ones fixed to machines. Hence, it is important to choose one that perfectly fits the bill.
It is advisable that you get in touch with a professional to get advice on the best kinds of magnetic contactors and choose the one that best matches your requirements!