Resin transformers are a modern category of electrical devices that provide a safe alternative to traditional oil transformers. At Onninen, we offer a comprehensive range of these technologically advanced solutions that ensure reliable electricity distribution in the most demanding applications.
As a leader in the installation market, our many years of experience show that resin transformers are characterized by an exceptional level of fire safety and operational reliability. These features make them an ideal choice for facilities with increased safety requirements.
Check resin transformers (dry) at Onninen warehouse
What characterizes resin transformers?
Resin transformers, also known as dry resin transformers, are electrical devices that use epoxy resin as an insulating material instead of oil. In Onninen's assortment, you will find transformers with power ratings from 160 to 3150 kVA, with insulation levels from 1.1 kV to 36 kV.
Construction and design of resin transformers
Modern resin transformers consist of a three-column core made of cold-rolled transformer steel, covered with inorganic insulation. The low-voltage windings are made of copper strip or parallel conductors with a profiled cross-section, while the high-voltage windings consist of round or profiled wires.
A key structural element is the vacuum impregnation of the windings with epoxy resin, which provides excellent electrical insulation and protection against moisture and mechanical contamination. After winding, the winding forms a compact monolith with high mechanical and electrical strength.
Advantages of resin transformers
- Fire safety - absence of flammable oil and the use of flame-retardant materials
- Environmental resistance - operation in temperatures from -60°C to +55°C
- Minimal maintenance requirements - no need to monitor oil condition
- Resistance to moisture, dust, and contamination
- High mechanical strength against shocks and stresses
- Self-extinguishing materials that do not emit toxic gases
Where are resin transformers used?
From our experience as a provider of energy solutions, it follows that resin transformers find wide application wherever safety and reliability are a priority.
Public utility facilities
| Type of facility | Key benefits |
|---|---|
| Hospitals and clinics | Fire safety in operating rooms |
| Schools and universities | Protection against disturbances in laboratories |
| Shopping centers | Safe operation in large crowds |
| Airports | Reliability of critical systems |
Industry and energy
We recommend resin transformers from our offer for industrial applications where stable energy distribution is required. They perform excellently in:
- Manufacturing plants with increased fire risk
- Wind and solar farms
- Data centers requiring uninterrupted power supply
- Installations on offshore platforms
- Chemical industry facilities
- Residential and commercial construction
In Onninen's assortment, you will also find distribution transformers ideal for residential estates, office buildings, and hotel complexes, providing safe power supply in limited installation space.
Special properties of resin transformers
Resistance to extreme conditions
Our team of experts recommends resin transformers particularly for use in harsh environmental conditions. These devices can operate effectively over a very wide temperature range and in environments with high humidity or contamination.
Environmental and climatic classes
Professional resin transformers available at Onninen meet the highest classification standards:
- Class E2 - resistance to salinity and aggressive environments
- Class C2 - operation in extreme temperatures up to -25°C
- Class F1 - highest fire safety
Overload capabilities
From our experience, resin transformers can operate under overloads of up to 
450% of the rated power for short periods, and with the use of fans - up to 140% of the rated power for extended periods, providing additional flexibility to the power supply system.
Why are resin transformers the future of energy?
Compliance with environmental standards
As a leader in the installation market, we know that resin transformers meet the latest requirements of the Tier 2 Ecodesign directive, which means minimal environmental impact and high energy efficiency. Our branches across Poland ensure access to top-class energy devices.
Innovative technical solutions
In Onninen's offer, you will find transformers equipped with advanced monitoring systems:
- PT-100 sensors for measuring winding temperature
- Temperature control relays with alarm functions
- Forced ventilation systems
- Anti-vibration pads
Flexibility of configuration
We recommend from our assortment transformers in various special configurations:
- Transformers in protective enclosures
- Devices with increased primary voltage
- Transformers for cooperation with inverters
- Versions with side low voltage output
Frequently asked questions
1. What are the main differences between resin and oil transformers?
Resin transformers use epoxy resin as an insulator, while oil transformers use mineral oil. Resin transformers offer higher fire safety, no need for oil maintenance, and the ability to operate in harsher environmental conditions. They do not require monitoring of oil insulation condition and are more resistant to contamination.
2. In what temperatures can resin transformers operate?
The operating temperature range is from -60°C to +55°C in the standard version. Special versions can operate even at temperatures down to -50°C, making them ideal for applications in arctic climates or at high latitudes.
3. Do resin transformers require special maintenance?
Resin transformers have minimal maintenance requirements. The absence of oil eliminates the need for regular inspections of oil insulation condition, oil level checks, or filter replacements. Only periodic checks of mechanical condition and electrical parameters are necessary.
4. What power can resin transformers have?
The standard power range for resin transformers is from 160 to 3150 kVA. On special order, it is possible to manufacture transformers with power up to 25 MVA at voltages up to 40.5 kV. The insulation level typically ranges from 1.1 kV to 36 kV.
5. Why are resin transformers safer in terms of fire?
The insulation systems are made of flame-retardant and self-extinguishing materials. The absence of oil eliminates the risk of ignition of flammable liquids, and epoxy resin does not emit toxic gases at high temperatures. The materials meet the highest fire safety standards of class F1.
6. Where are resin transformers most commonly installed?
Resin transformers are mainly installed in hospitals, shopping centers, schools, and industrial facilities. They are particularly suitable for places with limited space, high fire safety requirements, and where uninterrupted energy supply is required in critical systems.
Professional energy solutions at Onninen
As a leader in the distribution of energy solutions, Onninen offers a comprehensive selection of resin transformers from renowned European manufacturers. Our many years of experience in the installation industry allows us to deliver solutions tailored to the most demanding projects.
Our team of specialists provides professional technical advice on selecting optimal transformer parameters for specific applications. With a wide network of branches across Poland, we guarantee quick availability of products and comprehensive support at every stage of project implementation.
Investing in high-quality distribution transformers from Onninen ensures reliability, safety, and energy efficiency for many years of operation. We invite you to contact our experts to select optimal solutions for your projects.