Encapsulated and Cast-Coil Cast-Resin Transformers: Key Features and Applications

As power systems place higher demands on safety, reliability, and energy efficiency, dry-type transformers are becoming a preferred alternative to traditional oil-filled designs. Among them, encapsulated and cast-coil cast-resin transformers are widely adopted due to their stable insulation performance, fire safety, and strong resistance to harsh environments.

These transformers are now commonly used in industrial plants, commercial buildings, renewable energy projects, and critical infrastructure where safety and reliability are essential.

What Is an Encapsulated and Cast-Coil Cast-Resin Transformer?

An encapsulated and cast-coil cast-resin transformer is a dry-type transformer in which the windings are fully sealed using epoxy resin through a vacuum casting process. The solid insulation structure protects the windings from air, moisture, dust, and chemical contamination.

Unlike oil-immersed transformers, cast-resin transformers do not contain flammable insulating oil. This significantly reduces fire risk and eliminates the possibility of oil leakage, making them suitable for indoor and environmentally sensitive installations.

Key Technical Characteristics

Vacuum Casting Process

The windings are cast in a vacuum environment to remove air bubbles and impurities. This results in a dense and uniform insulation layer that improves electrical stability and reduces partial discharge.

The process also helps achieve consistent heat dissipation and long-term operational reliability.

Advanced Insulation Materials

Modern cast-resin transformers use high-performance epoxy resin systems combined with flame-retardant and environmentally friendly additives. Many designs also incorporate nano-modified insulation materials to enhance mechanical strength and thermal performance.

Heat-resistant insulation systems rated at Class H or higher allow stable operation under high temperatures and heavy load conditions.

Integrated Monitoring Functions

To support intelligent power systems, encapsulated cast-coil transformers can be equipped with temperature sensors, partial discharge monitoring, and communication interfaces. These features enable real-time status monitoring and simplify maintenance planning.

Main Advantages

Encapsulation with epoxy resin provides excellent insulation performance and isolates the windings from moisture and contaminants. This slows insulation aging and extends service life.

The absence of insulating oil greatly improves safety. Cast-resin transformers are suitable for indoor installation in public areas where fire protection is critical.

Strong resistance to moisture, dust, and corrosion allows reliable operation in humid, polluted, or chemically aggressive environments.

The solid insulation structure requires minimal maintenance. There is no need for oil testing or replacement, which reduces operating costs over the transformer’s lifetime.

Even heat distribution within the windings improves load capacity and enhances thermal stability during continuous operation.

Typical Application Areas

Industrial Power Distribution

Encapsulated cast-coil transformers are widely used in manufacturing, electronics, chemical processing, and food industries. Their stable performance and low maintenance requirements make them suitable for demanding industrial environments.

Commercial Buildings and Public Facilities

Shopping malls, office buildings, hospitals, airports, and subway systems benefit from the fire-resistant and oil-free design of cast-resin transformers, allowing safe indoor installation close to load centers.

Renewable Energy Projects

Wind power plants, photovoltaic stations, and energy storage systems require equipment that can withstand outdoor conditions and load fluctuations. Epoxy cast dry-type transformers meet these requirements with reliable long-term performance.

Data Centers and Precision Equipment

For applications with strict power quality requirements, cast-coil transformers provide stable voltage, low noise levels, and minimal electromagnetic interference.

Encapsulated and cast-coil cast-resin transformers offer a balanced combination of safety, insulation reliability, environmental resistance, and low maintenance. These characteristics make them an ideal choice for modern industrial, commercial, and renewable energy power systems.

As a professional power equipment supplier, we manufacture cast-resin transformers in strict compliance with IEC and GB standards. Advanced vacuum casting technology and environmentally friendly materials ensure consistent electrical performance and long service life.

Contact us to discuss customized transformer solutions and obtain detailed technical specifications and quotations.