AC Contactor vs DC Contactor: Key Differences

Knowing the difference between AC contactors and DC contactors helps you to select the correct ones for your industrial usages. You will be using them in electric circuits but they will be different types of current. So, this article is going to dissect the AC and DC contactor so that you know exactly what you need for your power distribution systems.
What is a Contactor?
Contactors may be defined as switches which are controlled by electricity and, more frequently used for switching an electric circuit on and off again and especially in the case of high current applications to control, say, a motor starter, an electrical switch that would be difficult to turn on and off by hand. A contactor will be made up of a coil and a number of contacts that are opened and closed depending on the amount of electricity flowing. Control of motors, lights, heating elements and any electrical device utilized in industrial electrical applications is made easier by the use of the contactor as a controlling switch.
AC Contactor
An AC contactor is one which is designed for the control of alternating current power systems. There are many existing applications for the use of the AC power system in industrial use, meliorate to apply for the control of motors, heating, lighting and other various applications. The contactors are designed bearing in mind that the current reversing as it does.In addition, there must be materials used that are able to deal with the arcing generated when the direction of the current is altered. Coil Voltage: The normal coil voltage for AC contactors is 110V, 220V or 380V etc depending upon the uses in the system
Use – Where is AC Contactor used? AC Contactor is used in wide applications, including industrial – motors, lighting control systems, HVAC applications etc.
DC Contactor
A DC contactor is designed specifically to deal with direct current (DC) systems. As opposed to the AC power which can flow back and forth, the characteristics of the resulting current is entirely different, and so the contactors also have to be designed differently. In DC Contactor, the direction of flow of current always remains the same and the various difficulties consequent on this have to be dealt with in providing the contacts.
Key Features of DC Contactors
Arc Suppression: With arcing when the contacts open, more likely. DC contactors are constructed preferably with features that help………..pipe while the contacts are open. Since it never passes through zero as in the case of an AC current, the breaking of contacts becomes relatively easier, and DC contactors will usually have magnetic blowouts or some similar type of arc-chamber construction.
Heavy Duty Contacts: To avoid rapid wearingCoil Voltage : Can vary from 12v in the case or that for motors for small loads, to arrangements for operating electric vehicles as discussed above, of the order of 48v.
DC contactors are used in applications where there are battery powered systems, such as electrics cars, or the likes of solar panels.
This post will introduce you to the differences between AC and DC contactors, tips on choosing the right for your application!
Key Differences Between AC and DC Contactors
Following is a brief table highlighting the key differences between AC and DC contactors:
AC ContactorDC ContactorCurrent TypeAlternating Current (AC)Direct Current (DC)Arc CharacteristicsEasier to stop arcing (yes due to rise of current)Harder to stop for constant currentContact MaterialsMaterials resistant to AC arcingHeavier duty materialsApplicationsMotor control, lighting, HVACElectric Cars, Solar panels, Battery storageCoil Voltage110V, 220V,390V AC12V, 24V, 48V DCPicking your Contactor type
The choice between an AC and DC contactor rests entirely with the actual AC and DC electrical systems you have in place. And it is around the following that you should give thought to:Power source – Is your power source AC? The choice of a AC contactor is clear. And vice versa. Current load – are you sending high current through your contactor – then place emphasis on the DC due to its more extreme arcing.System Efficiency – subclass chooses make system efficiency fall below optimum, certain types simply cannot afford to compromise in this way!
Summary and conclusion
Though the principal simplifies, we see that a standard contactor switching an electrical circuit is different whether it be switching AC or DC – particularly when, as usually is the case, summoning them must be done at a distance/ are remotely controlled. Understanding the differences will make you select the appropriate one. In doing so, we are likely to be found in as diverse places as power electronics to industrial applications, electric cars and beyond. Understand the differences, and make the right selection each time.