Transformers suitable for extremely hard environments

Subbiano Arezzo, Italy, April 2022 – Tesar successfully achieved the Test Certificate for the Environmental, Climatic and Fire behaviour classes E4-C3-F1 as per IEC 60076-11:2018 on a cast resin transformer with rated power 1000 kVA and rated voltages 20/0,4 kV BIL 125 kV in respect of the last ECO DESIGN Tier2 losses as per EU 548/2014 and EU 1783/2019.

The following tests were successfully carried out on the same transformer:

  • Thermal shock test C3
  • Condensation and Humidity penetration test E4
  • Fire behaviour test and checking of gases emission F1

The tests were attended and certified by an independent third-party laboratory, CESI, in Milan.

What does each class certification grant the product and why was it chosen?

C3 means that the transformer is suitable for transport and storage at temperatures down to -40°C, making it so there are very few places on earth where it cannot be placed, and energized and operated at -25°C, a temperature that avoids installation problems and is not reachable in indoor installation or inside of an enclosure for outdoor use (IEC 60076-11 Ed.2 2018-08 paragraph 12.1).

E4 means that the transformer is suitable to be installed in places with direct access to harsh environments: areas close to industry where conductive dust and industrial smoke are abundant, areas close to the coast and exposed to salt spray or to very strong and polluting winds from the sea, desert areas, (characterized by no rain for long periods), exposed to strong winds carrying sand and salt, and subjected to regular condensation (IEC 60076-11 Ed.2 2018-08 paragraph 12.2).

F1 is required to install transformers in places subject to a fire hazard such as buildings or places where many people gather (i.e., hospitals, public buildings, industrial) and guarantee restricted flammability and emission of toxic substances and opaque smoke (IEC 60076-11 Ed.2 2018-08 paragraph 12.3).

“Tesar had to overcome various challenges to achieve the certification, among them the research of the best combination of insulation materials capable of sustaining harsh environmental conditions that would not impact the overall selling price of the transformer too much.” – Luigi Corsico, Sales Director at Tesar

Fulfilling the requirements for the certification means that Tesar’s transformers are suitable to work in environments close to the sea, desert areas or heavily polluted areas and ones with extremely cold temperatures. For an Italian company it is a step forward toward meeting the requirements of the customers more strictly due to the increase of special installations.

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About CESI
CESI is a world-leading technical consulting and engineering company in the field of technology and innovation for the electric power sector. Through its Division, KEMA Labs, CESI is the world leader for the independent testing, inspection and certification activities in the electricity industry. CESI operates in 70 countries around the world and supports its global clients in meeting the energy transition challenges.

About Tesar
Tesar is part of the Swiss-based R&S Group, a leading provider of electrical infrastructure products in key markets around the globe. With manufacturing facilities and offices in Europe, the Middle East, and South America, R&S is a major supplier of transformers and switches for customers in the utility, industry, and infrastructure sectors.