1,000+ Electrical Transformers (7.2–34.5 kV, 25–3000 kVA) — UL Evaluated, Certificate of Compliance Available — In Stock & Ready to Ship from Houston, CA & Florida. Contact Us Today!
Safe • Reliable • Efficient • Low Maintenance
Up to 10 MVA | 35 kV | 50/60 Hz
Cast Resin | VPI | VPE
F/H Insulation | IP20–IP65
IEEE C57.12.01 · IEC 60076 · CSA C22.2 No. 47
Lead Time：12-14 weeks
Daelim Transformer offers a complete range of dry transformers in its portfolio. We offer three different technologies: Cast resin (epoxy-encapsulated), VPI (vacuum-pressure impregnated for indoor use) and VPE (vacuum-pressure encapsulated with fiberglass reinforcement). Each of the technologies guarantees zero leakage, minimal fire risk and minimal maintenance.
We manufacture dry-type transformers with rated power up to 10 MVA and voltage up to 35 kV. They are available for frequencies 50/60 Hz and insulation classes F or H. They are manufactured according to IEEE C57.12.01, IEC 60076 and CSA C22.2 No. 47 standards and are characterized by DOE/Eco Design Tier 2 efficiency. With protection from IP20 to IP65, Daelim Transformer dry-type transformers provide reliable performance in accordance with all regulations worldwide.
Dry Transformer
We offer three types of dry transformers, but the highest standard of applied technologies and a wide range of technical specifications.
Product | Cast Resin | VPI dry transformer | VPE dry transformer |
Rated capacity | Up to 10 MVA | Up to 10 MVA | Up to 10 MVA |
Rated voltage | Up to 35 kV | Up to 35 kV | Up to 35 kV |
Insulation material | Epoxy resin | Polyester with fiberglass | Epoxy encapsulation |
Insulation class | F or H (155 °C / 180 °C) | F or H | F or H |
Winding material | Copper or aluminium | Copper or aluminium | Copper or aluminium |
Vector group | Dyn11/Dyn5/Dyn1 | Dyn11/Dyn5/Dyn1 | Dyn11/Dyn5/Dyn1 |
Tap changer | OCTC, OLTC on request | OCTC | OCTC |
Tapping | ±2×2.5% or ±5% | ±2×2.5% or ±5% | ±2×2.5% or ±5% |
Enclosure IP rating | IP20 to IP65 | IP20 to IP65 | IP20 to IP65 |
Frequency | 50/60 Hz | 50/60 Hz | 50/60 Hz |
Cooling methods | (Air natural, air forced) AN / AF | AN / AF | AN / AF |
Standards | IEEE C57.12.01, IEC 60076, CSA C9 | IEEE C57.12.01, IEC 60076, CSA C9 | IEEE C57.12.01, IEC 60076, CSA C9 |
Operational life | 25-30 years | 25-30 years | 25-30 years |
Application | Industry, high polluted environments, high humidity zones | Indoor applications | Extreme outdoor conditions |
Technical specification of Daelim Transformer’s dry transformers
Feature | Description | Customer benefit |
Cast resin design | The entire transformer winding assembly is immersed in epoxy resin under vacuum. This prevents the penetration of dirt and moisture, and the deterioration of the insulation characteristics. | The transformer has been protected from negative environmental influences for years. Maintenance intervals are much less frequent than standard transformers. |
Vacuum pressure impregnation | The windings are saturated with polyester or varnish under pressure and vacuum and then baked to harden the insulation system. | Lower manufacturing cost, with excellent resistance to moisture penetration. Excellent option for interior installation, where fire protection is important. |
Vacuum pressure encapsulation | The windings have additional fiberglass reinforcements and encapsulation layers to achieve mechanical strength. | Better resistance to thermal cycling, vibration and physical stress than cast resin type transformers. Ideal for outdoor use, marine installations and industry. |
Lack of liquid insulation | Transformers do not use a liquid insulator. Cooling is carried out exclusively by air. | No oil leaks, oil testing and ignition hazards. No need for fire suppression systems. Transformer insurance is cheaper. Faster manufacturing, delivery and permitting. |
Fire resistance | Epoxy resin and polyester have high flame resistance and are self-extinguishing. | Non-combustible materials that do not provide an additional source of fuel in the event of a fire. Suitable for indoor installations. |
Resistance to high short circuit current | The coils are very strong and stable, unlike oil-immersed coils which are more easily moved. | Ability to withstand strong mechanical forces in the event of a short circuit. Damage to the windings is rare, which reduces the operational cost of these transformers. |
Reduced noise | The design of the core and the materials used ensure strength and stability, reducing the possibility of vibration and noise. | It can be used in busy spaces, without disturbing office workers, patients or building occupants. |
Standards compliance | Daelim Transformer manufactures transformers according to IEEE/ANSI, CSA, IEC 60076, EN 60076, AS/NZS and other local standards. | One manufacturer for projects anywhere in the world. |
Dry transformers are most commonly used where the risk of oil leakage or fire is extremely high, and can negatively affect people and the environment. Extreme application locations, sensitive consumers or simply densely populated urban areas, are just some of the places where dry type transformers are the gold standard.
At Daelim Transformer, we have delivered solutions for the following types of applications:
Application | Solution | Result / Advantages |
Commercial buildings | ● Cast resin transformer ● No oil leakage & containment ● Less frequent maintenance ● No fire suppression system | ● Increased facility security ● Lower operating costs ● Easier to obtain permits |
Hospitals | ● Transformers rated for hospital systems requiring uninterrupted power supply ● Zero risk for surrounding rooms | ● Ensures continuous operation of life-saving equipment ● Transformers meet rigorous requirements |
Metro, tunnels & underground infrastructure | ● Reduced vibrations with VPE transformers with fiberglass reinforcements ● Withstands warm and dusty underground environments | ● In accordance with fire safety plans ● Passengers and workers are protected |
PV plants & wind turbines | ● Cast resin transformers designed for specific PV and wind power environments ● Mounted next to solar panels or in the turbine itself | ● No risk of fire or damage on the solar power plant or wind turbine ● Overall maintenance is easier |
Data centers & IT critical infrastructure | ● VPI transformers ● UL/cUL certified for North America market | ● Fewer weak points and more secure data center operation ● Cheaper insurance |
Offshore platforms | ● VPE transformer with adjustable coatings ● Withstand motion and aggressive atmosphere | ● Enhanced crew safety ● The movement has no significant impact on the transformer operation |
With the dry transformer options offered by Daelim Transformer, there are many different combinations. The customization process is tailored to your needs and requirements.
Customization Category | Customization options |
Enclosure configuration | ● IP rating from IP00 to IP54 ● Customized cable entry (top or side) ● Paint and coating customization |
Electrical parameters | ● Voltage ratio, voltage group and tap changer type and ratio ● K-factor rating ● Impedance voltage designed according to fault level and relay protection settings |
Insulation & environmental adaptations per IEC 60076-11 | ● C1 or C2 climatic class ● E1 or E2 environmental class ● F0 or F1 fire behaviour class ● Insulation classes: B, H, F or C |
The choice of the appropriate technology depends mostly on the operating conditions of the future transformer. Cast resin dry transformers are ideal for polluted environments, with high humidity and difficult access. If it is a standard indoor application without extreme operating conditions, and you do not have a very large budget for a transformer, the best choice is the VPI dry transformer. In places where vibrations, high loads and extreme thermal cycles are present, the VPE type is an ideal option.
Like all other transformers manufactured in our factories, the dry type also undergoes the same procedure – core production, winding installation with special reinforcements and final testing. All these steps are managed in one place and overseen by our engineering team and in accordance with the standards and regulations defined through the contract with the customer.
Standard/Certification | Regional scope | Daelim Transformer compliance/customer benefit |
IEC 60076 / EN 60076 | International & European standard | Full compliance with both standards alongside with CESI verification for European markets |
UL / cUL | North America product safety certification | Covers specific manufacturing models, voltage ratings, materials |
CSA | Canadian electrical safety and performance standard | Full compliance with CSA requirements |
SGS | Global inspection, testing, verification and certification company | SGS allows independent verification before final payment |
IEEE / ANSI | North American design & performance standard | Compliance with technical standards for transformer design, testing and performance |
AS / NZS | Electrical equipment performance standard in Australia & New Zealand | Compliance on all transformer specifications on the Australian continent |
The lack of oil in dry transformers significantly simplifies the logistics process. There is no nitrogen blanket, insulation contamination or oil leakage is impossible, and the load is lighter. Your dry transformer is transported more like electrical equipment than dangerous goods. Our packaging standards include:
Our transformers are safely transported, whether it is an LCL or FCL arrangement, respecting the standards of sea and road transport. Air transport is organized for urgent deliveries. Any form of transport of a dry transformer is fundamentally more sustainable, given the lighter load.
The condition of the transformer during transport is monitored by shock recorders, and all evidence from production to the arrival of the transformer at your location is documented.
Delivery of the transformer is not the last step. Our team of engineers is available for any kind of on-site assistance such as installation, assembly and commissioning. Our team offers training on the operation and maintenance of transformers, to ensure the quality and correct use of your device. Remote and video support is included in the initial price
The minimum warranty period for our transformers is 24 months, and can be extended to 60 months, with customized terms, according to the client’s needs. Our teams in several locations around the world offer support for the installation, commissioning and maintenance of your dry-type transformers.
Support element | What do you get? |
Warranty period | Minimum 24 months; extendable up to 60 months |
Local/Regional after-sales teams | Client support teams after transformer delivery – professional support in all phases of transformer operation |
Remote support | Remote management of various operations such as assembly, commissioning and all other needs (suitable for hard-to-reach locations) |
Technical support | You have contact with the team that designed your transformer – you get guidance for specific design of cast resin, VPE and VPI transformers |
Windings re-impregnation | VPI windings that have been mechanically damaged can be re-impregnated – available as a warranty or post-warranty service |
For all locations where it is too dangerous to risk fire, toxic fumes and oil leakage, dry transformers are the ideal solution. Daelim Transformer offers a proven solution through three technologies: cast resin, VPI and VPE transformers that provide superior performance that cannot be achieved with oil transformers.
If a dry transformer is a potential solution for your applications, contact us directly so that we can find the most optimal solution. Describe to us the environment of your installation, voltage class, required capacity and standards you want to apply. Within 48 hours you will receive a technical solution, equipment specification and budget price.
A dry type transformer is a device that uses air and solid insulation materials for cooling and insulation. The main advantages are increased safety, low maintenance requirements and is most commonly used in indoor commercial, industrial and renewable energy environments.
Dry-type transformers offer better fire protection, they have low potential for environmental pollution, and are generally easier to maintain. On the other hand, they have a higher initial cost, limited power ratings, and are not suitable for heavy loads.
Dry-type units use air and solid insulation materials for cooling and insulation, while liquid-filled transformers use only oil. Dry-type units are used mainly indoors, where safety and low environmental impact are a priority. Oil-filled transformers have higher efficiency at higher rated powers, and are an indispensable solution for high power applications.
The choice between these three types of dry transformers primarily depends on the operating environment and protection requirements. Cast resin transformers are the best option for harsh, humid and dusty environments due to their excellent resistance to outdoor conditions and low maintenance requirements.
VPI transformers are ideal for clean and dry indoor environments, while VPE transformers are somewhere in between, providing better protection from external influences than VPI, but being more economical than cast resin transformers.
Dry-type transformers require significantly less maintenance than oil-immersed transformers. For reliable operation, routine inspections are required, including checking electrical connections and checking for overheating or insulation deterioration.
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