AC Magnetic Contactors

AC magnetic contactors are electrically operated switching devices used to control and switch AC power circuits. An electromagnetic coil operates the main contacts, allowing a separate control circuit to switch connected electrical loads. Three-phase AC magnetic contactors are commonly used for motors, pumps, compressors, heating equipment, lighting systems, and industrial machinery.

ATO offers 3 phase AC magnetic contactors with current ratings from 115A to 630A and coil voltage options of 24V, 110V, and 220V. Available ratings include 115A, 150A, 185A, 225A, 265A, 330A, 400A, 500A, and 630A, covering different three-phase AC load and control requirements.

How AC Magnetic Contactors Work

When the coil is energized by the specified control voltage, it generates a magnetic force that actuates the contact mechanism and changes the state of the main contacts. This switches the connected AC load on or off through the control circuit. When the coil is de-energized, the contact mechanism returns to its normal state. This allows a lower-power control circuit to operate higher-current AC loads without the control device directly carrying the load current.

Key Specifications

• Current Ratings: 115A, 150A, 185A, 225A, 265A, 330A, 400A, 500A, and 630A
• Coil Voltage: 24V, 110V, and 220V
• Phase: 3 phase AC
• Operation: Electromagnetic coil control

Applications

3 phase AC magnetic contactors are used where AC loads need to be switched through an electrical control circuit. Common applications include:

1. Motor Control: Switching three-phase motors used in machinery, pumps, fans, compressors, and other equipment.
2. Industrial Machinery: Controlling motors and other AC loads in production and automated equipment.
3. Heating Equipment: Switching heating elements and other resistive AC loads.
4. Pump and Compressor Systems: Controlling motors used in water, air, and process systems.
5. Lighting Systems: Switching grouped AC lighting loads through an electrical control circuit.
6. Electrical Control Panels: Integrating AC load switching into industrial control and power distribution systems.

Selecting an AC Magnetic Contactor

Select an AC magnetic contactor according to the electrical characteristics of the load and the requirements of the control system. The following factors should be considered:

• Rated Current: Select a contactor rated appropriately for the load current and operating conditions.
• Coil Voltage: Match the coil voltage to the available control circuit voltage, such as 24V, 110V, or 220V.
• Load Type: Consider whether the contactor will switch a motor, heating equipment, lighting, or another type of AC load, as switching requirements can differ.
• Operating Voltage: Confirm compatibility between the contactor and the voltage of the AC power circuit.
• Motor Starting Current: For motor applications, consider starting current and operating characteristics in addition to normal running current.
• Installation Conditions: Consider the control panel, enclosure, ambient environment, and available installation space.