Contactors

In simple terms, a contactor, contactor switch or contactor relay is a device designed for switching an electrical circuit on or off. They are part of the relay family, but the main difference is that a contactor is used in applications with higher current capacity is involved. Contactors are typically used for motors, lighting circuits, heating, and other electrical loads. A contactor can function on its own or as a power control device or as part of a motor starter.

RS offer a comprehensive range of high-quality electrical contactors from industry-leading brands including Schneider Electric, Siemens, Eaton, ABB, and Allen Bradley. We also stock a selection of accessories used to enhance the function of the contactor including, contactor overload relays, auxiliary contacts, mechanical interlocks, and much more.

What Are Electrical Contactors?

Designed to be connected to high-current load devices, contactors incorporate spring-loaded contacts that make or break power supply lines to a load. These contacts are designed to open and close very rapidly to assist with arc suppression, ensuring the contactor's ability to interrupt heavy motor currents with minimal damage over a longer life cycle. In any device that is frequently turned off and on, a contactor is often employed, and different contactor configurations are designed for different current requirements. From uses in basic light switches to complex applications such as controlling electromagnets, contactors are highly versatile.

How Do Contactors Work?

Contactors, unlike standard relays, are specifically designed to connect to high current load devices. Used in larger-scale control circuit applications, a contactor is a switch that can be controlled remotely, specifically designed to switch a large amount of electrical power through its contacts. If a device can switch more than 10 amperes, it is called a contactor. These devices also feature high coil voltages which are rare within relays.

Why Are Electrical Contactors Important?

Electrical contactors are essential for controlling high-voltage circuits with low-voltage signals. They ensure safe and efficient operation of electrical systems by enabling remote switching, protecting circuits from overloads, and extending equipment lifespan through reduced electrical wear. Their reliability and durability make them crucial in both industrial and commercial applications.

Contactor Specifications

There are various types of contactors, and each type will have its own set of specifications depending on your application. Some key specifications are:

AC Contactor or DC Contactor with coils including 12 V, 24 V, 48 V, 110 V, 240 V, 400 V, and 440 V.
Reversing or non-reversing functionality.
AC3 and AC1 categories.
Contactors with 2 poles, 3 poles, 4 poles, and even 8 and 10 pole variants.
Various contact configurations.
IEC standards.

Industrial Applications of Electrical Contactors

Electrical contactors, like ac contactors, are widely used in industrial applications to control heavy machinery and equipment. They are essential in motor control centres for starting and stopping motors, managing HVAC systems, and operating lighting systems. Contactors are also crucial in manufacturing processes, where they automate conveyor belts, pumps, and compressors. Additionally, electrical contactors also play a vital role in power distribution networks by ensuring the safe and efficient operation of high-voltage equipment, enabling remote operation, and protecting against electrical faults. Their robustness and reliability make them indispensable in maintaining smooth and safe industrial operations.

Contactor Price

The price of ac electrical contactors and other contactors can vary widely, ranging from MYR16.71 for basic models to over MYR203.541 for advanced, high-capacity units, depending largely on specifications and brand.

What’s the Difference Between a Relay and a Contactor?

Relays and contactors both control electrical circuits, but they differ in their applications and capacities. Relays are typically used for low-power applications, handling currents up to 20 amps, and are suited for signalling, automation, and small load switching. Contactors, on the other hand, are designed for high-power applications, capable of handling currents up to several hundred amps. They are robust and durable, making them ideal for controlling heavy machinery and industrial equipment. On top of that, contactors often include arc suppression and overload protection features.