- by Todd Benadum
- April 24, 2025
- Dry Type Transformers, Transformer Build Process
Dry type transformers usually contain windings — or coils — that act as conductors. Transformer builds typically have primary windings and secondary windings. The primary windings create input power flow, while the secondary windings convert the power and transmit it to the load through input leads.
Transformers with disc windings have conductors wound on the flat sides of the disc, while transformers with layered windings use conductors that cross each other from bottom to top. Windings consisting of either copper or aluminum can perform similar functions. The type of conductor used in dry type transformers will depend on the unique requirements of the application.
The Role of Conductors in Dry Type Transformers
Although low- and medium-voltage transformers sometimes contain aluminum windings, many engineers prefer copper windings because of their superior properties. First, copper windings are significantly more conductive than their aluminum counterparts. Second, copper is much more reliable because of its superior strength, so it offers exceptional resistance to deformation and protection against fault current stresses.
Because of its lower price, some manufacturers choose aluminum for windings in less demanding, low-voltage applications. While some manufacturing companies use both options for dry type units, copper windings are the industry standard due to their optimal performance.
Conductor Specifications for ELSCO Dry Type Transformers
ELSCO dry type transformers feature some of the industry’s most efficient designs, with 100% copper windings, laminated steel cores and premium-grade insulation. We hand-wind these units and assemble them under strict quality control parameters at our state-of-the-art Cincinnati facility. We test all transformers multiple times during manufacturing to ensure each client receives a high-quality product that will provide many years of reliable service.
Our primary windings feature disc-wound, round coils with Nomex-insulated copper magnet wire or wire covered with heavy armored polythermaleze (HAPT). Disc-wound designs are standard in core-form transformers with ratings over 25 kilovolts. Because of its exceptional performance, we also use disc winding in our 5- and 15-kilovolt units.
The round-coil windings offer increased strength for transformers with medium and high voltages.
Our secondary windings contain Nomex insulation with copper conductors wound in strips to minimize vertical forces. ELSCO dry type transformers carry a basic insulation level (BIL) rating equal to liquid-filled designs.
Advantages of Our Dry Type Transformer Conductors
What sets ELSCO Transformers’ copper conductors apart from the competition is our manufacturing process. Each conductor is drawn to exact specifications with strict quality control to create precise dimensions and surface quality. This superior accuracy leads to consistent electrical properties throughout the winding assembly, eliminating any weak points that can lead to premature failures.
Our copper conductors undergo specialized heat treatment processes that enhance electrical conductivity and mechanical durability. This high attention to detail results in conductors that maintain their performance characteristics even after thousands of thermal cycles over decades of service.
Integrated Cooling System Design
The insulation and cooling systems in our transformers work together with the copper conductors. Strategically placed air channels between the winding layers create a chimney effect that enhances the cooling process. This capability increases the surface area exposed to the cooling air while maintaining the proper electrical clearance.
We size and position the cooling ducts based on thermal modeling that accounts for the load profiles of different applications. This approach means that no section of the winding will experience excessive temperature rises, even under varying load conditions.
Temperature Monitoring and Protection
We place thermal sensors in our transformers to track the operating temperatures and prevent damage to the windings by alerting operators and maintenance crews before temperatures reach unsafe levels. When temperatures exceed safe limits, alarms let operators know when to reduce the load or perform maintenance, helping prevent transformer failures that could lead to costly downtime and damage to connecting equipment.
By continuously tracking the temperature of the windings, core and other key components, operators can detect overloads, cooling system failures, insulation degradation and other abnormal conditions.
These value-added features are among the many reasons businesses and organizations choose our transformers for their power distribution needs.
Learn More About Conductors for Transformers With ELSCO
If you want to learn more about how ELSCO Transformers’ medium-voltage, dry type transformers can benefit your unique application, our knowledgeable and experienced team can guide you. Besides offering new transformer builds, we provide additional services to handle your transformer needs, including custom bus work, retrofitting and emergency replacements.
Complete an online quote form today to obtain pricing for our products. You can also call 800-232-9002 with questions or to request additional product information.
