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Sealed Coils

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When we use an electric motor, we are actuating a set of factors that are designed to keep the motor running and ensure its performance. At the heart of any electric motor is an electric coil, which is a set of wires that have been tightly wound to form a cylinder. All electric motors have some type of coil. The design of the coil depends on the application and the needed current to run the motor. Read More…

Sealed Coils When we use an electric motor, we are actuating a set of factors that are designed to keep the motor running and ensure its performance. At the heart of any electric motor is an electric coil, which is a set of wires that have been tightly wound to form a cylinder. All electric motors have some type of coil. The design of the coil depends on the application and the needed current to run the motor.
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Leading Manufacturers

Sag Harbor, NY  |  800-724-5952

We are proud of the craftsmanship of our engineers. All of our products are made right here in the United States and we promise that these items are created from high quality resources. Our electrical coils are unique and efficient.

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Sag Harbor Industries, Inc. $$$

Bristol, CT  |  800-825-4319

Established in 1973, Classic Coil Company is a Contract Manufacturer of electronic coils. We manufacture coils for a variety of industries; winding wire gauges from 4-58 AWG. We are ISO 9001-2015 certified, ITAR registered and DFARS Compliant. Our Engineering services allow us to assist with design, reduce cost, and increase efficiency in production. Call or visit our website to learn more about our capabilities.

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Classic Coil Company $$$

Bristol, CT  |  860-584-0927

We are an ISO 9001:2015 certified company which is internationally known for manufacturing high quality electromagnetic-coils. It is our goal to provide quality products, a commitment to speedy delivery, and competitive pricing. We understand that every application is unique, so we encourage you to contact us to discuss your specific requirements. Call us at 1-860-584-0927 and find out what our 50+ years of experience can do for you.

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Quality Coils, Inc. $$$

Alpha, NJ  |  800-867-3526

Since 1962, Torelco has been a supplier of electric coils and transformers of superior quality. We offer custom coils, solenoid coils, ferrite core coils & toroid wound coils to serve a range of industries. Markets served include medical, military, electronics, and industrial. When you work with us, our promise is to build to the exact specifications and meet the custom needs of our customers.

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Torelco $$$

Antigo, WI  |  800-826-9741

Johnson Electric Coil Company is a family owned manufacturer that specializes in custom transformers, coils and inductors. From three phase isolation transformers to single phase inductors and chokes, we carefully design our products to meet your exact specifications.

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Johnson Electric Coil Company $$$
placeholder image Sag Harbor Industries, Inc. Classic Coil Company Quality Coils, Inc. Torelco Johnson Electric Coil Company

Most motors are used in normal conditions at a factory, office, or home. Seldom do those motors have to face conditions that may damage the coil or interfere with the operation of the motor. There are circumstances when a coil may be faced with situations where it will have to endure a more aggressive and hostile atmosphere. Motors designed to operate in those conditions require an extra layer of protection to prevent them from failing. The type of coil designed to meet those kinds of applications is referred to as a sealed coil.

What is a Sealed Coil?

The name of a sealed coil is a full definition of what it is. Sealed coils are tightly wound insulated coils that have been treated with an extra layer of material as a form of protection. The manufacture of a sealed coil follows the normal process of winding and insulating. Once the coil has been completed, it is sealed with a type of material, which can be a polymer resin, epoxy, or silicone resin.

There are several reasons to seal a coil in an extra layer of protection. The most obvious reason is as a means of protection against the elements from damaging a coil and preventing it from performing properly. Moisture is one of the biggest concerns. The process of injecting a liquid material over a coil and baking it makes it impenetrable.

Another benefit of sealed coils is their ability to dissipate heat, a major factor in the deterioration of electronic devices. The tight-fitting seal is forty times more efficient at removing heat and keeping the coil cool.

Materials Used to Seal a Coil –

Some of the most common materials used to seal coils are chosen for their ability to adhere to the coil wires and fill in the gaps and empty spaces that are common to electrical coils. Some of the popular materials are polymer resin, silicone resin, and epoxy, with polymer resin being the most used.

Epoxy is one of the more sturdy and durable materials that has thermal stability and able to resist a wide variety of liquids and gases. When it is applied to a coil, it easily fills in the gaps and empty spaces to enhance the performance of the coil.

As with epoxy, polymer resin is an excellent sealing material with the added feature of being able to seal windings and laminations as a means of dampening noise and lessening the vibrations produced by spindles. A benefit of polymer resin is how it solidifies and becomes rigid after the curing process.

Silicon resin has all of the properties of polymer resin and epoxy with the additional ability to perform at a wide variety of temperatures. The process for applying silicon resin is to inject it into a coil.