Our range

Cooling type: ONAN/KNAN
Oil Natural Air Natural: natural circulation of the oil inside the transformer and natural convection of the air outside.
High fire-point Oil Natural Air Natural: natural circulation of the high-fire point oil inside the transformer and natural convection of the air outside.

Cooling type: ONAF/KNAF
Oil Natural Air Forced: natural circulation of the oil inside the transformer and forced convection of the air outside using fans.
High fire-point Oil Natural Air Forced: natural circulation of the high-fire point oil inside the transformer and forced convection of the air outside using fans.

Cooling type: OFAF/KFAF
Oil Forced Air Forced: forced circulation of the oil inside the transformer using pumps and forced convection of the air outside using fans.
High fire-point Oil Forced Air Forced: forced circulation of the high-fire point oil inside the transformer using pumps and forced convection of the air outside using fans.

Cooling type: OFWF / KFWF
Oil Forced Water Forced: forced convection of the oil inside the transformer using pumps and forced convection outside by means of a pressurised water circuit. The transformer is cooled by an oil/water heat exchanger.
High fire-point Oil Forced Water Forced: forced circulation of the high-fire point oil inside the transformer using pumps and forced convection outside by means of a pressurised water circuit. The transformer is cooled by an oil/water heat exchanger.

Tank type: Corrugated tank
The four sides of the tank consist of partially elastic corrugated steel panels; this increases the surface area for cooling the oil circulating inside the tank by natural convection. The outside air circulates between the panels by natural or forced convection.

Tank type: Flat wall tank
The tank containing the active part (i.e. the magnetic circuit (core) and windings) of the transformer must be completed with a cooling system.

Tank type: Flat wall tank + radiators
Radiators are added to flat wall tanks to allow heat dissipation by natural or forced convection of the air between the radiator fins inside which the oil circulates naturally.

Filling type: Hermetic
The transformer is entirely filled with oil and hermetically sealed (no air-oil contact). The oil is cooled by natural circulation of the oil inside the tank’s radiators or corrugated walls. The expansion of the oil when it is heated is taken up by the elasticity of the radiators or corrugated walls. celduc® transfo is specialised in high capacity hermetically sealed transformers and the only manufacturer of hermetic solutions for ratings up to 20 MVA.

Filling type: Free breathing with conservator tank
The transformer has an expansion tank called a conservator tank mounted on top of the main tank, which provides space for the oil which expands as it heats up. The oil is in direct contact with the air, which is dried first by a chemical desiccant or through an elastic membrane.

Number of secondary windings: 1 to 6-pulse
The power on the primary winding is exactly the same as that on the secondary winding, less the transformer losses.

Number of secondary windings: 2 to 12-pulse
The power on the primary winding is divided between two separate secondary windings. This configuration improves the performance of a variable frequency drive placed on the secondary winding of the transformer thanks to a dual phase-shifted power supply. celduc® transfo is world leader in transformers for variable frequency drives.

Number of secondary windings: 4 to 24-pulse
The power on the primary winding is divided between four separate secondary windings. This configuration improves the performance of a variable frequency drive placed on the secondary winding of the transformer thanks to a quadruple phase-shifted power supply. celduc® transfo is world leader in transformers for variable frequency drives.

CE – Hazardous area (Ex): Yes
The transformer is compliant with Annex II of European Directive 2014/34/EU and by extension with the rules of the International Electrotechnical Commission and can be used in potentially explosive atmospheres (ATEX/IECEX). At the customer’s choice, compliance can be self-certified or certified by an independent accredited body. celduc® transfo is world leader in ATEX/IECEX transformers.

CE – Hazardous area (Ex): No
The transformer cannot be used in a potentially explosive atmosphere.

CE – Reduced losses: Yes
The transformer complies with European Directive 2009/125/EC implemented by Regulation No. 548/2014 relating to the ecodesign of power transformers. The transformer’s no-load losses, also known as core losses or iron losses, corresponding to the energy dissipated in the form of heat when the transformer is energised at no load, are minimised by using more material in the core. This European Directive applies to all transformers installed in the European Union, subject to certain exemptions.

CE – Reduced losses: No
The transformer does not comply with European Directive 2009/125/EC and therefore cannot be installed in the European Union, although there are some exemptions, mainly for applications on VFD-motor loads or highly inductive loads in transient states. celduc® transfo is world leader in transformers for variable frequency drives.