Dry-type transformers

Dry-type transformers up to 10 000 kVA and 72.5 kV

BTB Trafo Cast Resin webpageDry-type transformers are used when you want to minimize the risks for fire hazard and environmental contamination. Dry-type transformers are a good choice for installations in office buildings, warehouses, hospitals and other indoor facilities.

Standard Design

Our standard dry-type transformers are manufactured to meet the requirements of international standards (IEC).
Other national standards (e.g. ANSI) is available upon request.

Our standard dry-type transformers are made with aluminum conductors and with insulation according class F. The insulation system  is cast resin for high voltage windings and  vacuum pressure impregnation (VPI) for low voltage windings. The transformers are equipped with bolted links for off-circuit voltage regulation in steps of ±2x2.5%. Our standard transformers are naturally air cooled (AN) and IP00 (unenclosed). Upon request can standard types of painted steel sheet enclosures be provided at different ingress protection classes (IP-class)

The energy losses are standardized according to EN standards; normal and low losses. Other specific requirements in terms of energy losses can be achieved with our customized design.

The level of accessories and monitoring equipment is limited to such types that can be fitted to the standard design.

“With our standard design we want to achieve high quality transformers that will give our customers good value for money thanks to full scale serial production of standard design. “

Customized Design

These transformers will be made to order and handled as an individual project to be sure that all specific requirements are met.

We can offer various winding concepts (VPI, VPE, Glass Fibre Reinforced). The glass fibre reinforced windings gives better environmental protection for extreme installations and operational conditions.

The customization process covers everything from both electrical and mechanical design parameters to the level of accessories and instrumentation. This gives us the possibility to meet special customer requirements in respect of operation as well as for instance installation in places with space restrictions.

“We are flexible to meet various customer requirements with our customized design.“


Special Features

With the customized design we can offer following special features:

  • Dual primary or secondary voltages
  • Design also suitable for special applications such as; converter, rectifier, furnace, motor starting, windmill, marine etc.
  • Various connections and phase displacement
  • Temperature rise according to site conditions
  • Increased insulation level with increased withstand to lightning and overvoltage peaks
  • Encosures according to customer requirements with various level of ingress protection (IP-class)
  • IP protection cabins according to customer requirement
  • Surface treatment for harsh conditions
  • Cooling fans for ANAF operation with increased power rating
  • Voltage regulation with motorized on-load tap changer
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Phone : +358 6 7210 222
Fax: +358 9 2319 4343
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