Since 1964, celduc transfo is the French specialist of customized immersed transformers and small series production.


Groupe celduc his implanted in Sorbiers (42) since 1964…

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Our transformers

Manufacturer of “customized” immersed power transformers, our range extends from 50 kVA until 17 MVA

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References and Application fields

Oil & Gas, Sailing propulsion, Power station, Cement industry, Steel industry…

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celduc transfoWith many years of experience, celduc transfo study office calculate and design entirely the various transformers according to the technical specification or customer’s requirements.
Search of electrical performance, isolation level, thermal sizing, protection factor… constitute the daily task of our designer team.
Charging rate, installation conditions, surface treatment… all is taken in consideration for the transformer as built for a long time.


Our transformers winding and assembly are entirely achieved in our plant in SORBIERS.
We can manufacture low losses equipment, according to the U.E N°548 rule of European directive.
Multiple characteristics of different types of windings are mastered.

celduc transfo atelier celduc transfo fabrication


celduc transfo essais All manufactured transformers are tested in routine tests according to the CEI 60 076 standard.
Our tests platform can also realize typical or special tests such as :
  • Temperature rise test,
  • Noise level test,
  • Lightning impulse test,
  • Oil dielectric strength.
  • Test realized according to customer’s requirements or during FAT (Factory Acceptance Tests) receipts in factory in presence of our customers.

The voltage level applied to the tested transformers can be until :
  • 140 kV for applied voltage test,
  • 325 kV lightning impulse test.


transfocelduc transfo company works on international market for 80%.

From simple truck loading until SEI4C packing with ship or plane transport,
logistics is an essential point to define with customer in order to meet the deadline.