Siemens Energy GEAFOL cast-resin (dry-type) transformers
A safer, simpler way to deliver dependable distribution power
GEAFOL® Cast-resin (Dry-type) Transformers
Wherever distribution transformers have to assure the utmost safety in areas frequented by people, GEAFOL® cast-resin transformers are the ideal solution. With GEAFOL, the limitations of liquid-filled transformers are avoided, but the proven electrical, mechanical and especially thermal characteristics are retained.
Safety
Safety
Oil-free, flame-retardant cast-resin insulation for safer installs in people-dense areas.
Reliable
Reliable
Vacuum-cast windings built to handle moisture, thermal cycling, and harsh conditions.
Eco-friendly
Eco-friendly
Dry-type design reduces spill risk, supports recyclability, and enables efficient operation.
GEAFOL transformers from Siemens Energy exceed the highest safety standards and comply with all relevant laws and regulations.
Exceeding highest quality standards
GEAFOL dry-type transformers conform with the fire behavior, environmental and climate classes defined in standard IEC 60076-11 as follows:
- E3 Environmental class (higher classes on request)
- F1 Fire behavior class (highest defined class)
- C3 Climate category (higher classes on request)
Complying with the laws and regulations affecting distribution transformers
Siemens Energy is closely monitoring the development of transformer regulations worldwide, e.g. the European Eco Design Directive and US DOE rules. Siemens Energy adheres to the rules and regulations communicated, e.g. in the US and Europe, and complies with all relevant requirements for every transformer product delivered. As a trusted and responsible partner, Siemens Energy understands the importance of these regulations and will continue to monitor potential future requirements. Siemens Energy will continue to adapt and comply with all relevant regulatory changes.
We produce the GEAFOL in accordance with VDE 0532-76-11/IEC 60076-11/DIN EN 60076-11 and the Ecodesign Directive from the European Commission. Other standards, such as GOST, SABS, or CSA/ANSI/IEEE, can also be taken into account on request. GEAFOL dry-type transformers can also be designed to meet special national specifications or customers' wishes. The high quality standard of the GEAFOL transformers was confirmed from the result of several tests: for example, one and the same GEAFOL transformer has passed all defined routine, type, and special tests, as well as additional tests, with flying colors. The comprehensive safety certification enables use in almost every environment and under extremely harsh conditions such as:
- Ambient temperatures of ± 60°C
- Aggressive, salt-laden atmospheres
- Great mechanical stress e.g. on ships, cranes or nacelles of wind power plants
The GEAFOL principle has succeeded in producing transformers with excellent electrical, mechanical and thermal characteristics, which have also proved to be particularly compatible with the environment.
Maintenance-free & eco-friendly insulation
GEAFOL dry-type transformers are insulated with an epoxy resin and quartz powder mixture – an eco-friendly material that makes the winding:
- Almost maintenance-free
- Moisture-resistant
- Tropicalised
- Flame-retardant
- Self-extinguishing
No toxic gases are produced, not even under the effects of arcing. And the specially developed spacers of the coil support system ensure isolation of vibrations from the iron core, which means very low noise levels.
Electrically safe aluminium foil winding
The coils of the high-voltage windings are made of aluminum foil.
Why foil windings?
- They combine simple winding techniques with high electrical safety.
- Insulation is subjected to less electrical stress than in other types of windings.
- The result: high power frequency and impulse voltage withstand capability.
Why aluminium?
- Thermal expansion coefficients of aluminum and cast resin are similar.
- The result: thermal stresses due to load changes are kept to a minimum.
On request, we also offer dry-type transformers with copper windings, named CARECO.
No gas inclusions during casting process
The high voltage windings are potted with epoxy resin under vacuum at a high temperature:
- Undesirable gas inclusions are prevented.
- Freedom from partial discharges (up to twice the rated voltage) is provided.
The low-voltage strip winding is also made of aluminum. The width of the aluminum strip is equal to the length of the coil:
- Axial short-circuit forces in the transformer are reduced.
The conductor strip and insulation material are bonded together by heating:
- A compact unit with sufficient strength to reliably withstand radial forces is created.
GEAFOL transformers are insulated with an epoxy resin/quartz powder mixture instead of oil – a very environmentally friendly alternative. Besides, GEAFOL dry-type transformers are completely recyclable.
GEAFOL transformers from Siemens Energy are produced as Sensformers by default. This means they are equipped with sensors that transmit operational status data to a secure storage and analytics tool. Operators can optimise operations based on customised data analytics.
For our GEAFOL dry-type transformers, we offer accessories and tailored solutions that suit your individual needs. Here is a selection of additional equipment available upon request:
Temperature monitoring
PTC thermistor temperature sensors, PT 100 resistance temperature detectors or a capillary tube thermometer can be employed for temperature supervision of GEAFOL transformers.
Radial-flow fans
Radial-flow fans with temperature-dependent control can be installed to provide capacity reserves and to cover peak load periods. In this way, the transformer output can be raised by up to 50 percent.
Housing
To provide protection for the transformers against environmental influences and to prevent people from coming into contact with the transformer, we offer standard housings, and optionally, modified housing designs.
Connection
To simplify installation and connection, the transformer is optionally available with connection on the HV or LV side, top, or bottom. Plug connections are available as well.
