Air & Vacuum Contactors

RESA Power offers a wide variety of contactors designed for starting and controlling three-phase, AC motors. They are offered in a variety of vacuum or air configurations, 480V through 7200V. Contactors are frequently used when motors are in continuous, heavy-duty cycling applications where the contact life is critical.

Air vs. Vacuum Contactors

While air contactors (also known as air break contactors) are the most widely used switching devices in motor control starters, vacuum contactors offer notable benefits for certain power system environments.

The switching action that occurs in an air contactor takes place in the open air, allowing the atmospheric pressure to extinguish the arc that resulted from the switch. A vacuum contactor, however, utilizes a vacuum bottle to create a sealed environment for the switching to take place in, allowing for fast and clean action in a harsh or dirty workplace environment. Not only does this prevent external factors from affecting the switching action, but the controlled vacuum bottle also helps to extinguish the arc quickly in medium-high voltage applications – leading to reduced downtime and better overall contact reliability.

Air contactors are a common choice for low voltage applications, as they are reliable and cost-effective. They use air to extinguish the arc that is created when the contacts open, and are able to handle high continuous currents. However, they can be large and require regular maintenance to ensure proper functioning.

Vacuum contactors, on the other hand, use a vacuum to extinguish the arc and are a great choice for medium to high voltage applications. They are smaller in size, have a longer lifespan, and require less maintenance than air contactors. They are also more energy-efficient and can provide better control over the flow of electricity.

However, vacuum contactors can be more expensive than air contactors and may not be suitable for all applications. It’s important to work with an experienced electrical engineer who can help you determine which type of contactor is best for your system based on its specific needs and requirements.
In some cases, a combination of air and vacuum contactors may be the best option. For example, air contactors can be used for the main power control and vacuum contactors can be used for secondary control.

No matter which type of contactor you choose, it’s important to select a high-quality product that is reliable and fits your system’s needs. Proper maintenance and regular testing can also help ensure the contactors continue to function properly over time.

RESA Power’s expert engineers can help you determine which type of electrical contactor is best for your power systems and operation. We stock new, used, and hard-to-find power contactors from all major manufacturers, as well as an extensive inventory of other motor control components. If you don’t see the part you’re looking for, contact us today for a custom quote.