Oil immersed transformers

As defined by IEC60076 standards, distribution transferors are rated up to 2500Kva. Ardan also manufactures larger transformers, you can read more about them in the "small power transformers" where we go up to 15,000 Kva and up to 36Kv.
Our transformers are fitted for pole mounted design with expansion tank and also for ground mounting with hermetically sealed tanks.
Having quality at the top of our mind, the process of designing and manufacturing each and every transformer is performed to perfection, from the core to the tank, from the coils to the paint you can expect a top workmanship.

The Core
The magnetic core of Ardan transformers is manufactured using magnetic grain oriented silicon steel sheets. This type of steel is highly permeable by the magnetic field and its fluctuations, thus reducing no load losses for the transformers and reduced the noise omitted by the transformer.
The joints between columns and yokes are Step-Lap inserted sheet, so that the magnetic stream flows more easily, no load current and noise are reduced and the core has a good mechanical stiffness. External tie rods connect the upper and lower clamps and creates a rigid support for core, windings and outlets.

Low Voltage foil windings
The axial current distribution can adjust itself freely in the conductors. Thus axial forces which occur in short-circuits as result of inevitable asymmetries, are avoided. Axial contraction forces have no effects in the foil conductor. In order to control the radial forces the winding insulation consists of prepreg, a pressboard sheet which is coated on both sides with non-cured resin. Following the winding process the low voltage windings are placed in a heating oven to go under a heating process for tightening and strengthening the mechanical construction of the coil. The low voltage outlets mainly consist of massive cupper bars. They are welded to the conductor in either a cold welding/ press technic or with TIG welding process to achieve maximum conductivity.
 
High Voltage Layer Winding
The round or square shaped enamel-insulated conductors are directly wound with constant force on a pressboard cylinder. A heat shrinkable tape is attached externally for further mechanical solidity. The layer insulation is made of a high quality paper pack adapted to electric stress. This process yields a compact winding with high short circuit behavior and optimal impulse-voltage distribution.

The Tank 
Corrugated walls are used in Ardan's transformers up to 5 MVA and radiator construction is suitable for up to 15 MVA. All tanks are tested individually for leaks while pressurized and inspected under ultraviolet light. The tank is pained in a dipping technology thus assuring complete coverage of all particles in the tank, this process has been proved to be the most professional process to fit paint coverage to be used in aggressive conditions such as high temperatures, moist, salty and hi polluted environment.
 
Vacuum Drying
Following the assembly of the active part it enters a drying process in a vacuum industrial oven. The moisture in the insulating parts is heated and drawn out of the system to guarantee flawless work of the transformer. After being heated and dried the active part is placed in the tank construction to be filled with isolating fluid. Whether it is mineral oil or synthetic oils such as Midel eN or Cooper FR3, the transformer are filled under sub pressure environment to assure adequate sealing process.

Quality above all
Each transformer is tested in our laboratory according to IEC 60076 requirements for routine tests. For customers who wish further testing we offer special tests as indicated in the relevant standards. Customers are welcome to witness our lab process and testing facility.
Setting world precedent defect rate of less than 0.004%, Ardan is proud in its quality and strongly believe that a job well done is a job done once…