In today’s fast-paced world of technology and industrialization, the need for a stable and controlled electrical system is more critical than ever. In this context, a contactor is an essential device that effectively fulfills this need. Contactors are essential for making connections and interrupting current as needed. Their systems are pretty extensive, covering everything from heating and cooling to motors and more. Installing contactors makes operations more manageable and safer.
Different Electrical Contactor Types
Types Of Contactor
With all the technological advancements, contactors have become more and more effective and personalized every day. Several types and standards of contactors available in the market, each with its own unique principles based on the situation. We can categorize contactors based on their voltage ratings, applications, and functionality.
The contactor type and function, according to their respective applications, can be summarized as follows:
Knife Blade Switch
The knife blade switch is the old contactor type, which is based on the simplest functions but slow at the same time. It works similarly to other contactors and can be used to start or stop a circuit.
It’s got a metal blade or knife with a lever to turn it on or off. It is not practical for high-voltage use, so it is not commonly used for industrial or large-scale setups. Another shortcoming of this type of contactor is the risk of corrosion due to moisture content and increased wear and tear due to manual operation, which shortens its functional life.
Knife Blade Switch Diagram (Source:@elprocus.com)
Manual Contactor
The manual contactor is an improved yet smaller form of knife blade switch. As the name suggests, it is controlled manually by an operator. Being an outdated version of a contactor, knife blade switch has some drawbacks and risks, which have been worked upon and removed in the manual contactor. It is also known as a double-break contactor as it gives ease of operation by simultaneously opening the circuit at two places.
Electromagnetic Contactor
It is the most up-to-date and preferred type among all contactors. It is a magnetic contactor type available in AC and DC configurations. The contactor coil activates the circuit by attracting the contacts via an electromagnetic field. It has been widely used in motors or high-load machinery industries. It is a better switching option that is energy-efficient, reliable, and safer.
Electromagnetic Contactor Structure Diagram
Thermal Contactor
The thermal contactor is the type of contactor that works multipurpose. It not only acts as an electrical switch for circuits but also protects them from overheating damage. It has a built-in protection system to protect against overheating caused by high currents. It causes the circuit to stop and trip as long as there is a high current.
Modular Contactor
A modular contactor is also an electromagnetic contactor used for switching any electric circuit. You have the option to either operate it manually or use any other electrical control system. The contactor working is carried out with the help of electromagnetic force.
When the coil is energized, it creates a magnetic field, eventually pulling the moving contact toward the fixed contact, thus closing the circuit and allowing the current to flow through. They not only are capable of withstanding high currents but also provide enhanced protection by tripping the contactor in case of excess current.
That is why they are preferred over other traditional contactors. They are suitable for controlling scheduled lighting circuits in industrial and residential units, electric motors in industries, or HVAC systems. They come in both AC and DC options.
Modular Contactor and Timer Switch
Type of Contactors Voltage AC and DC
The basic working principle is the same for both types of contactors, except for the number of contactor coils or the type of current flow. Below is a brief yet detailed table to help you fully understand the differences between the two.
|
Points Of Difference |
AC CONTACTOR |
DC CONTACTOR |
|
Usage Type |
For Alternating current (AC) applications |
For direct current (DC) applications |
|
Functionality |
Controls power with variable directions | Controls power flowing in one direction |
| Working Principle | Use magnetic fields produced by alternating current |
Use a magnetic field surrounding the coil |
|
Frequency Of Operation |
600 times/hour variable | 1200 times/hour constant |
| Size | It is more compact and comparably smaller than DC contactors |
Larger than AC contactor |
|
Electrical Resistance |
Lower electrical resistance | Higher electrical resistance |
| Material Used In Plating | Laminated Silicon sheets |
Iron core |
|
Shape |
E-shape | U-shape |
|
Applications |
Industries and homes | For solar systems and batteries |
| Longevity | More durable with less wear and tear |
Increased wear and tear due to continuous current flow |
| Type Of Arc | Grid arc |
Magnetic quenching arc |
Types Of Contactor Applications
Industrial Applications
Contactors are among the first-hand devices used for controlled operations of machinery, transformers, and motors in the industrial sector. They help start and stop the machinery on time. Contactors are also used in electric furnaces in production industries.
Power Distributions Applications
The share of contactor applications in power distribution is a major one. Contactors are used to monitor and control power flow to different electrical systems according to the need. They are widely employed for this purpose in industries, arenas, commercial projects, and power distribution houses in small towns and cities.
Magnetic Contactors Used in Main Power Distribution Boards
Residential Applications
ACs and electric heaters are two examples of contactors in residents. They are also used in emergency alarms, refrigerators, fans, and water motors that are installed in homes.
Commercial Applications
Contactors are used in commercial set-ups and buildings for scheduled lighting or alarm systems. They are also an integral part of the HVAC systems of the infrastructure. Not only that, but they are also used to control the elevators.
Type of Contactor Utilization Ratings (IEC 60947)
It refers to the type and nature of the current load that a contactor can handle. It is a long list of contactor ratings, out of which the most common ones are contactor types AC1, AC2, AC3.
- CONTACTOR TYPE AC1 – Simple non-inductive loads with no high currents
- CONTACTOR TYPE AC2 – For starting and switching off
- CONTACTOR TYPE AC3 – Inductive loads with high current
- CONTACTOR TYPE AC4 – Starting, plugging, and inching duty
Frequently Asked Questions
1. Are AC And DC Contactor Type Of Contactors?
Yes, AC and DC contactors are types based on different types of current, alternating and direct. They both work the same way except for the kind of current and applications they are used for: AC contactors are used for alternating or variable current, while DC contactors are used for direct or constant current.
2. What Are The Type Of Contactors Used In Industry?
Many types of contactors are ideal for use in industries, depending on the type and nature of the electrical system and the current load. Generally, the most used types are modular, electromagnetic, thermal, and manual contactors.
3. What Is The Difference Between Contactor And Circuit Breaker?
A contactor is a device used for switching electrical circuits with on/off operations without giving any protection against short circuits and high current. In contrast, a circuit breaker is a device exclusively used for protecting against overload or short circuits.
Wrap Up
A contactor is an inevitable device when it comes to the smooth and uninterrupted operation of your desired electrical system. Whether you are looking for an electrical switch solution for your industrial set-up, workplace, or residential use, LETOP Modular contractors must be your top pick for a complete package of versatility, durability, and functionality.
We are among the frontline manufacturers of the most premium quality electrical devices and switches in the international market. Now is the high time you equip your system with the most updated types of contactors from LETOP. Contact us now.
