Our Transformer Production Processes

ELMAKSAN TRANSFORMERS manufacture DISTRIBUTION TRANSFORMERS with power between 25 kVA and 2500 kVA, up to 6,3-11-20-36 kV voltage level, complying with TS, IEC, ANSI and BS standards and national voltage levels as required by customers, HERMETIC type fully closed to atmosphere or EXPANSION TANK type open to atmosphere.


All of our Transformer Winding processes are wound with modern winding machines.

Distribution Transformers Windings:
Low voltage winding conductor copper Layer insulation in sheet windings is provided with thermally improved resinous paper (DPP).

High Voltage winding conductor copper Windings are enameled round copper wire, insulating paper covered flat copper wire. Layer windings are wound by computer controlled fully automatic machines, layer insulation is formed in wedge shape with electrical insulation papers in the form of strips (electrical kraft, thermally improved kraft and resin thermal paper). This layer insulation structure created increases the resistance of the winding against overvoltage impulses; This method provides gap-free, solid, coils with excellent properties.

Distribution Transformers Windings:
Low voltage and high voltage winding conductor is copper. Depending on the transformer power, the windings are wound by using copper wire covered with insulating paper as floor winding, continuous disc winding, helical winding or screw winding.

Magnetic Circuit

It is cored type and manufactured of M5, M4 and M3 silicon alloyed sheets with thicknesses 0.30, 0.25 and 0.23 mm of which crystals are directed. 45 degree inclined cut sheets are used for transition zones of magnetic circuit. All sheets used in magnetic circuit are cut and stored by CNC controlled cutting machine and magnetic circuit is formed by allocating these sheets. 

Cutting and allocating of magnetic circuit is handled by a method called step-lab and which reduces iron losses to the minimum level. Core is aligned by cross and longitudinal step-lab applications. 

Magnetic circuit cutting and arranging is done by a method called step-lab, which minimizes iron losses. The core is lined up with diagonal and longitudinal step-lab applications.

Our leg and yoke sections are equal, multi-stage and theoretically round in section.

Noise levels are minimized by tightening the core sheets with U profile and steel studs passing through the yoke insulated pipes.

Active Part

In order to form the active part of the transformer whose core and coils are ready, the coils are mounted by squeezing against the core and each other by means of laths in order to carry the radial forces, and the upper yoke is arranged. 

At the same time, the coils are equipped with a protection against axial forces. The necessary welding and connections of the adjustment leads to the commutator or step switch are made with silver electrodes and the active part is made ready for the furnace.

The active parts are dried in their ovens by air circulation method in order to remove the existing moisture in the solid insulation materials, within the framework of a program depending on the power and voltage of the transformer.


It is used for the protection of cooling and insulation material in oil type transformers. Depending on the cooling surfaces, transformers up to 3150 KVA are manufactured with wave walls, and in larger power transformers, they are manufactured as boilers with radiators.

CNC controlled plasma machine is used in boiler manufacturing. Boilers, whose assembly and welding works have been completed, are subjected to tightness test under pressure according to IEC standards. It is designed to have a vacuum resistance of 0.65 bar for wave wall boilers and 1 bar for boilers with radiators. Boilers, whose production is completed according to customer demand, are subjected to sandblasting. The boiler cover is designed to bring out the winding ends.

Kapak üzerinde izolatörler, faz işaretlemesi, aktif kısmın kaldırılması amacıyla kaldırma kulakları, termometre cebi, topraklama burcu ve ek donanımlar bulunmaktadır.

Technicial Specifications


After the transformers, whose active part assembly is finished, are dried in drying ovens at 120 degrees, they are placed in the tank and filled with oil in the vacuum chamber.

Vakum odasında transformatörün kazanının içinde kalmış olan hava emilir ve izolasyon yağının aktif kısmına tam olarak nüfus etmesi sağlanır. Doldurulan yağ yalıtım ve soğutmayı sağlar.


Boilers, whose production is completed, are painted with the spray method. Standard painting consists of a primer and two coats of topcoat. The total film thickness is not less than 105p. 

The standard transformer color is RAL7033, called cement gray.

It is possible to paint in different structures (such as zinc coating), in different thicknesses and in different color codes, according to the customer's request.


Routine Transformer Tests
  • Measuring winding resistances
  • Measuring conversion rates
  • Checking the polarity or connection group
  • Measurement of short-circuit voltage and load losses
  • Measurement of no-load losses and current
  • Induced voltage test
  • Applied voltage test
  • Measuring insulation resistances
  • Measurement of DC Insulation resistance
Type Tests
  • Temperature increase (Warm-up Test)
  • full wave impact test
  • Measuring the audible noise level
  • Boiler life test (For Hermetic Transformers)
  • Mechanical strength test against short circuits (This test is carried out in CESI/ITALY, IPH/GERMANY test laboratories abroad.)

*Except for the mechanical strength test against short circuits, all other type tests are carried out in our company's laboratory.

Special Tests
  • Checking the breakdown voltage of oil
  • Measuring the missing angle (DOUBLE Experiment)
  • Measuring paint thickness


In distribution transformers up to 1600 kVA, the Dyn 11 (TRIANGLE/YILDIZ neutral removed) connection type standardized by TEDAŞ is applied, other connection types can be used if desired. 

For networks with high unbalanced loads in phases, transformers up to 200 kVA can also be connected as Yzn 11 (STAR/ZICZAK - neutral removed) if desired. In transformers larger than 1600 kVA, the connection type requested by the customer is applied.