Brief Overview of Different Applications of a Contactor

by Thomas

When a person refers to DC and AC contactors, they might be talking about the control unit or the device’s circuit being switched either on or off. On this blog post, you will learn the applications of DC and AC contactors while describing their uses too.

Whereas the consistently charging voltage of a DC contactor plays a considerable role in extinguishing arcs within the AC circuit, anytime there is some voltage; a DC contactor will always rely on various mechanisms to suppress arcing.

One of the most important and notable differences between the DC and AC contactor is the fact that a DC contactor is made in such a way that it can quickly suppress the electric arcing anytime the contacts open as well as close in a full circuit.  

For instance, different voltages are known to be lower for DC than for AC circuits.

The gaps between their contacts are, therefore, wider in the DC contactor.

Applications of DC Contactors


Electric arcs are examples of the lesser familiar but pretty common fourth state in the plasma world, for example, where electric shock and neon lights are involved.  

To increase temperatures such as the kinetic energy in a product, experts have in place stable and gases, coupled with plasmas.

Plasmas are ionized, whereas electrons are orbiting atoms energized to the extent that the outermost electrons are capable of escaping. At the same time, the surrounding air is a natural insulator that becomes conductive.

Usually, at this point, the kinetic energy levels transported by the plasma are in different degrees Celsius. It can also become hotter than the sun. Precisely put, electric arcs are hot. They can damage the switch contacts by vaporizing the small options of the surfaces of contacts.  

Passing the electric current

When the electric current passes through a contactor, it will definitely cause the electromagnet to form a strong magnetic field. The magnetic field will then pull the armature into the coil while creating an electrical arc.  

Electric currents have a way of flowing from one contact into the machine where the contactor is appended. For that reason, the function of a contactor entails switching an electrical circuit off as well as on.

Overloading the circuit may be preventable where a thermal overload relay is added.  

If you have the feeling of deactivating the switch, then a contactor may be pulled from the parent device where it is appended.

Where the electric current is not flowing through, then the spring can easily push the armature, causing breakage in the connection.

Economical ways of switching currents

A DC contactor provides an economical way of quickly switching currents. How?

When addressing voltages, consideration should be given to the devices being switched using a contact.

These voltages should be defined not just in their nominal condition but at their extremes.

It is important to note that a voltage is usually defined as a dynamic parameter that is affected not just by the system design but by the state of maintenance as well as dynamic parameters. Some of these parameters include the current load, which may be imposed on a system at different moments.

The Rating of a Contactor

A contactor is rated using its design load and the current per contact, the duty cycle, and its voltage.

The general application of a contactor is based on starting duty on relatively larger motors.

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