How Can Dry Transformers Balance Safety, Cost Savings and the Future?

1. What Is a Dry Transformer?

2. Why Are Transformers Without Oil More Reliable?

3. How Do Dry Transformers Prevent Energy Waste?

4. Why Is It More Cost-Effective to Be More Expensive?

5. Conclusion

What Is a Dry Transformer?

A dry-type transformer doesn’t use insulating oil for cooling or insulation. Its windings and core are either open to air or encapsulated with solid materials like epoxy resin. Compared with oil-immersed transformers, it has clear advantages: fire resistance, environmental friendliness, and minimal maintenance. These traits make dry transformers a reliable choice for safety-sensitive sites, such as commercial buildings, industrial facilities, and the expanding new energy sector.

Dry transformers can be divided into several types according to insulation material and manufacturing process. The main categories include resin casting dry type, open-wound dry type, VPI dry type, and SF6 dry type. Among them, cast resin dry type transformers have emerged as the market mainstream, valued for their high safety, long service life, and minimal maintenance needs.

Why Are Transformers Without Oil More Reliable?

Oil-immersed transformers are widely used in power systems, relying on mineral oil for insulation and cooling. They offer high overload capacity and good heat dissipation. Low cost and mature technology keep them in service across many industries. But in high-risk environments, their safety and environmental drawbacks are hard to ignore. That’s why both international standards and national regulations call for dry transformers in crowded places—like hospitals, schools, and shopping malls—and in flammable or explosive sites such as chemical plants, oil fields, and gas stations.

• Fire and Explosion Risk

  With a flash point of only about 140 °C, insulating oil can ignite if a short circuit or overheating occurs. The resulting fire can be explosive. Burning oil releases hot gases that are difficult to contain and can quickly spread through a switchroom.

• Environmental Pollution Risk

  Transformer oil is hazardous waste. Any leak means costly cleanup and proper disposal, while improper dumping can lead to lawsuits and heavy fines.

• High Maintenance Costs

  Oil needs to be replaced every three to five years, and its quality checked often. If repairs require draining it, downtime can be long, and the hidden costs add up fast.

SHENGTE dry resin transformers use epoxy resin vacuum casting technology, removing the inherent safety risks found in oil-immersed designs and preventing issues such as leakage or arcing. With a dry core and windings, they operate without the need for traditional insulating oil. Cooling can be either natural or forced air, depending on the application. The result is a transformer that is safe, dependable, and operates without the need for routine maintenance.

Compared with oil-immersed transformers, SHENGTE dry-type transformers have unique advantages:

• Anti-Short Circuit & Temperature Control System: The high-voltage winding is vacuum cast with epoxy resin mixed with fillers, giving the coil low partial discharge and strong electrical strength. Glass fiber mesh plates are added to both the inner and outer walls of the winding, which beefs up the coil’s mechanical strength and helps the transformer take sudden short circuits better. On top of that, it comes with a high-tech temperature control system, so operations run safely and reliably.

• Safety & Environmental Protection: The casing adds a solid shield for the transformer, offering protection levels like IP20, IP23, IP30, or IP33. It’s crafted from materials such as aluminum alloy, cold-rolled steel, or stainless steel, among others. Fire-resistant and eco-friendly, it fits comfortably in load centers. Plus, it boosts overall safety without making a fuss.

• Easy Maintenance & Installation: Designed for fast setup, this unit is practically maintenance-free. It keeps daily costs low, saving you headaches and cash over time.

How Do Dry Transformers Prevent Energy Waste?

Is your transformer “stealing” electricity? Transformers generate no-load losses (iron losses) and load losses (copper losses) during operation. Traditional oil-immersed transformers are like “water heaters on 24/7,” consuming electricity even when not under load. So how can we prevent energy waste and reduce losses? SHENGTE three-phase cast resin dry power transformers offer the perfect answer.

SHENGTE’s Three-Phase Cast Resin Dry Type Transformer significantly reduces energy losses thanks to THREE CORE TECHNOLOGIES:

• Low-loss Silicon Steel Sheets: The core is constructed of high-quality cold-rolled silicon steel Sheets with a three-section, fully tilted lap joint structure. The core legs are bound with F-grade weft free straps and coated with epoxy resin to reduce no-load losses, no-load current, and core noise. Hysteresis losses are reduced by 30%, resulting in more efficient power transmission.

• Optimized Winding Design: The high-voltage winding is vacuum-cast with epoxy resin filler, resulting in low partial discharge and high coil electrical strength. The low-voltage winding utilizes a foil structure, eliminating the axial helix angle issue associated with wire winding and ensuring more balanced ampere-turns. Three-phase balancing technology reduces eddy current losses, making it particularly suitable for fluctuating load scenarios.

• Intelligent Temperature Control System: The transformer is equipped with a cross flow top blowing cooling fan, offering low noise, high air pressure, and an attractive appearance, enhancing the transformer’s overload capacity. An intelligent temperature controller is also included to prevent energy waste caused by overcooling.

Why Is It More Cost-Effective to Be More Expensive?

When purchasing transformers, many companies often focus solely on the initial purchase price, overlooking the hidden costs associated with long-term operation. This ultimately leads to a situation where they buy cheaply but end up with high costs.

For example, comparing oil-immersed and dry power transformers, while oil-immersed transformers may appear to have a price advantage, at 10%-20% lower purchase costs, they require approximately $3,000 in annual maintenance costs for inspections and oil changes, while dry transformers only require about $800 for simple dust removal. Furthermore, oil-immersed transformers carry significant risks, such as oil leaks and fires, resulting in significant losses in the event of a failure. Dry power transformers, on the other hand, operate virtually maintenance-free. At the end of their lifespan, oil-immersed transformers incur high disposal fees due to the hazardous waste they contain, while dry transformers can be recycled and even generate residual value.

Comprehensive calculations show that while dry resin transformers require a slightly higher initial investment, after factoring in full lifecycle costs, their total operating costs over five years are actually lower, truly achieving the economic benefits of “one-time investment, long-term benefits.”

Conclusion

Amid the global shift toward upgrading power systems and moving toward sustainable development, SHENGTE dry power transformers are gaining attention. With safety, efficiency, and environmental friendliness at their core, they’ve become a smart pick for both industrial and commercial users.

SHENGTE has been in the power industry for more than 15 years. As a leading dry type transformer manufacturer, we back our products with international certifications like IEC, ISO9001, and CE. Behind the scenes, a 10,000m² modern plant and an annual output of over 2,000 units keep our supply steady and our quality consistent. We also offer tailored solutions, including OEM and ODM services, along with a hands-on after-sales team to help you find the power setup that actually works for you. Whether it’s meeting tough fire-safety standards or cutting long-term energy use and costs, our technology is built to deliver.

Please contact us at juanie@shengtetransformer.com to receive a customized three-phase dry-type transformer solution. We look forward to establishing a long-term partnership with you to jointly promote the development of green energy!