Encapsulated Transformers

An encapsulated transformer is a dry-type transformer in which the core and coils are completely enclosed in a protective epoxy or resin compound. This encapsulation seals the electrical components from moisture, dust, and other environmental contaminants. The result is a durable, low-maintenance transformer that provides reliable performance in harsh or corrosive environments. Rex Power Magnetics encapsulated transformers are ideal for outdoor installations, marine applications, and industrial sites where airborne contaminants or high humidity could affect standard dry-type designs.

In resin-dipped transformers, the core and coils are coated with a protective film, but air remains within the winding spaces. In an encapsulated transformer, the coils are completely embedded in epoxy or resin, eliminating air pockets and forming a solid, sealed mass. This provides superior protection against moisture ingress, mechanical vibration, and corrosive atmospheres. Encapsulation also increases dielectric strength and reduces noise. Rex Power Magnetics employs high-quality encapsulating materials designed for excellent thermal conductivity and long service life.

Encapsulated transformers offer exceptional protection from environmental conditions that can cause electrical or mechanical degradation. The resin enclosure prevents dust, oil, and corrosive vapors from reaching the coils, allowing installation in wash-down areas, chemical plants, and outdoor enclosures. They are quieter than open-type designs, require minimal maintenance, and resist damage from vibration and shock. Because of their sealed construction, they can be installed close to the load without requiring additional environmental protection or ventilation systems.

Encapsulated transformers are commonly used in commercial and industrial facilities where exposure to moisture or airborne contaminants is expected. Typical applications include wastewater treatment plants, pulp and paper mills, food processing plants, marine vessels, and outdoor equipment enclosures. They are also used in mining, refineries, and agricultural operations. Rex Power Magnetics designs encapsulated transformers to provide dependable voltage transformation and isolation in both indoor and outdoor installations that demand robust environmental performance.

Each transformer is built with high-grade silicon steel cores and precision-wound copper or aluminum conductors. The coils are fully encapsulated in epoxy resin, forming a solid, sealed block that prevents the ingress of moisture or contaminants. The encapsulation compound also enhances mechanical rigidity and heat dissipation. The core and coil assembly is mounted within a corrosion-resistant NEMA-rated enclosure to protect against mechanical damage. This construction provides a compact, durable, and long-lasting transformer suitable for demanding applications.

Yes. Encapsulated transformers are specifically designed for outdoor or damp environments. Their fully sealed coil construction prevents moisture ingress, while NEMA 3R, 4, or 4X enclosures protect against rain, dust, and corrosion. The resin encapsulation ensures continued electrical performance even in high humidity or temperature fluctuation conditions. These transformers are ideal for wall or pad-mounted installations exposed to weather, washdown, or chemical atmospheres, eliminating the need for additional protective housing.

Encapsulated transformers are virtually maintenance-free. Periodic inspection should include checking terminal tightness, ensuring ventilation openings (if applicable) are clear, and verifying there are no signs of corrosion or mechanical damage. The encapsulated design eliminates the need for revarnishing or reconditioning of coils. In demanding environments, visual inspection of enclosures and connections should be performed at regular intervals. With proper installation, Rex Power Magnetics encapsulated transformers deliver years of trouble-free operation.

Yes. Rex Power Magnetics offers fully customized encapsulated transformers to meet specific electrical, mechanical, and environmental requirements. Options include special voltage ratios, kVA ratings, frequency ratings, enclosure materials, and mounting configurations. Custom encapsulation compounds and temperature-rise classes can be specified for unique applications such as marine or corrosive atmospheres. Every custom unit is built and tested to the same standards as catalog models, ensuring consistent performance and reliability in specialized environments.