Design Considerations for ETAC Custom Dry Type Transformers Part II

Discover ETAC’s design considerations for custom dry-type transformers, including core materials, winding configurations, and safety standards.

August 7th, 2024

In the last article, we covered core material selection, winding configurations, and winding materials. In this article, we will delve into additional critical design aspects of ETAC’s custom dry-type transformers, including insulation systems, cooling methods, enclosure types, and the importance of adhering to safety standards like CSA C9.

Insulation Systems

The insulation system is crucial for the safety and longevity of dry-type transformers. ETAC offers various insulation materials to ensure reliable performance:

Epoxy Resin: Provides excellent electrical insulation, mechanical strength, and resistance to moisture and chemicals. It is widely used in medium to high-voltage transformers.
Nomex Paper: Known for its high thermal stability and mechanical strength. It is suitable for high-temperature applications and provides reliable performance over a wide range of operating conditions.
Polyester Film: Offers good electrical insulation properties and is cost-effective. It is commonly used in low to medium-voltage transformers.

Selecting the appropriate insulation system ensures the transformer’s reliability and safety under various operating conditions.

Cooling Methods

Effective cooling is essential for maintaining the performance and longevity of dry-type transformers. ETAC employs different cooling methods based on the application requirements:

Natural Air Cooling (AN): Relies on natural convection to dissipate heat. This method is suitable for transformers with lower power ratings and is cost-effective.
Forced Air Cooling (AF): Uses fans to enhance air circulation and improve cooling efficiency. This method is suitable for transformers with higher power ratings and demanding applications.

The choice of cooling method depends on the transformer’s power rating, operating environment, and cooling efficiency requirements.

Enclosure Types

The enclosure of a dry-type transformer is crucial for protecting it from environmental factors and ensuring safety. ETAC provides enclosures that meet different standards to suit various applications:

NEMA 1 Enclosure: Designed for indoor use, NEMA 1 enclosures provide protection against accidental contact with the transformer and limited amounts of falling dirt. They are suitable for clean, dry, and controlled environments, such as offices and commercial buildings.
NEMA 3R Enclosure: Suitable for both indoor and outdoor use, NEMA 3R enclosures offer protection against falling rain, sleet, snow, and external ice formation. These enclosures are ideal for environments where the transformer is exposed to the elements, such as outdoor installations and industrial applications.

Choosing the right enclosure ensures the transformer is adequately protected and performs reliably under specific environmental conditions.

Enclosure Types

NEMA 1 Enclosure: Designed for indoor use, NEMA 1 enclosures provide protection against accidental contact with the transformer and limited amounts of falling dirt. They are suitable for clean, dry, and controlled environments, such as offices and commercial buildings.
NEMA 3R Enclosure: Suitable for both indoor and outdoor use, NEMA 3R enclosures offer protection against falling rain, sleet, snow, and external ice formation. These enclosures are ideal for environments where the transformer is exposed to the elements, such as outdoor installations and industrial applications.

Choosing the right enclosure ensures the transformer is adequately protected and performs reliably under specific environmental conditions.

Safety Standards

Compliance with safety standards is essential to ensure the reliable and safe operation of dry-type transformers. At ETAC, we adhere to the CSA C9 standard for our custom dry-type transformers.

CSA C9 Standard

Compliance with safety standards is essential to ensure the reliable and safe operation of dry-type transformers. At ETAC, we adhere to the CSA C9 standard for our custom dry-type transformers.

The CSA C9 standard, developed by the Canadian Standards Association (CSA), provides guidelines and requirements for the design, construction, testing, and performance of dry-type transformers. The standard ensures that transformers meet the necessary safety and reliability criteria, making them suitable for use in a wide range of applications.

Key Aspects of CSA C9:

Thermal Performance: Specifies the temperature rise limits and insulation system ratings to ensure the transformer operates safely under specified conditions.
Electrical Performance: Includes requirements for voltage regulation, efficiency, and short-circuit withstand capabilities.
Mechanical Design: Outlines the mechanical strength and durability requirements to withstand various environmental and operational stresses.
Testing Procedures: Details the testing methods for verifying the transformer’s performance, including dielectric tests, temperature rise tests, and short-circuit tests.
Safety Requirements: Emphasizes the importance of safe operation, including provisions for grounding, protection against electric shock, and fire safety measures.

Adhering to the CSA C9 standard ensures that dry-type transformers are designed and manufactured to meet high safety and performance standards, providing reliability and peace of mind to users.

Conclusion

Designing custom dry-type transformers at ETAC Service & Supply involves careful consideration of various factors to ensure optimal performance, reliability, and safety. Key considerations include core material selection, winding configurations, winding materials, insulation systems, cooling methods, enclosure types, and adherence to safety standards such as CSA C9. By addressing these aspects, ETAC engineers develop transformers that meet specific requirements and deliver efficient and reliable performance in diverse applications.