Active part and cap
Core coil and cap assembly are formed in a manner to enable them to be resistance against envisaged short circuit mechanical powers. In standard Transformers, the active part including the cap is attached to the boiler by means of bolts; there are also active part applications where attachment is directly made to the boiler, in line with the request of the customer, in such application, also transformers are manufactured. All connection elements on the cap and YG bushing arc horns are made up of stainless material or one with special coating which may resist against corrosion. Arrangement over the cap insulators, drum, and accessories are formed in line with the demands and specifications of the customer.

Cover
Transformer boilers and caps are manufactured from medium hardness steel. In Distribution Transformers, surfaces of boiler are formed wave wall panels which also functions as cooler. The pan section of tank is integrated by joining the walls and frame. It is also possible to use radiator groups with several slices as cooling surfaces. In Power Transformers, generally detachable radiator groups are used. Transformers which have capacity up to 4000 KVA, it is also possible to use wave wall panels as cooling surfaces. Each boiler of which welding works are completed is subject to pressure test before being dyed. If there is any welding contact fault, it is detected and contact fault is corrected. Each boiler and cap of which manpower works are completed is subject to sanding process. Applied standard sanding procedure is in line with DIN norm. If there is any special request or specification value of the customer regarding sanding, this is provided. If requested, it is possible to coat boilers by means of hot immersion galvanization method. Depending on the demand of the customer, it is possible for protection box made up of sheet compliant with IEC 144 STD to cover bushings on then cap or cable boxes may be assembled into side surfaces of transformer in line with BS 2562.

Dyeing
Each boiler of which manufacturing works are completed is dyed by means of spray method. Any standard dyeing consists of lining, final dye of two layers. Total film thickness is not less than 105µ. Standard transformer colour is RAL7033 which is called cement grey. It is possible to dye in different structures (such as zinc coating etc) and different thicknesses and different colour codes in line with request of the customer.

Drying and Oil
Transformer active part (Core +Coil) is dried inside drying furnaces running under high vacuum. Drying transaction is realized within the framework of a program formed depending on voltage and power. Oil filling is absolutely made under absolute vacuum.

Accessories
1. Oil Level Indicator: In Transformers with expansion tank exposed to Atmosphere, oil level indicators running magnetically in order to follow up and control the level of oil in expansion tank. Magnetic oil level indicators may have single or double electrical contacts. Contact oil level indicators transmit any unexpected and sudden changes in oil amounts in form of warning and opening signals. If demanded, it is also possible to use prismatic oil level indicators.

2. Dehumidifier: It is used in Transformers with expansion tank exposed to Atmosphere and is assembled to expansion tank. It takes humidity and dust out in the air which enters into expansion tank by means of silica gel which is inside it and increases operational safety of transformer. The amount of silica gel varies depending on the oil amount in transformer.

3. Oil Temperature Indicator: It is possible to follow up and control oil top temperatures of transformer by means of thermometers inserted into thermometer pockets welded on the cap or side surfaces of boiler. It is possible to use thermometers with maximum indicators, electrical non contact or single or double contact thermometers. Contact thermometers transmit warnings and opening signals in case where the temperature in transformer has exceeded the permitted level.

4. Buchholz, Gas Collection and Warning Relay: It is relay where the gases, formed by low and high density discharge and arcs occurring inside transformer, are collected. Relays may have single and double contacts. In line with gas amount collected in the relay, it is possible to have warning and opening signals. Due to such reason, it ensures that any fault inside transformer is detected before the same results in great destructions in transformer. Additionally, in case where the oil level falls below the level where there is no possibility to fully fill the relay for any reason, the relay informs this by means of a warning signal.

5. Hermetic Protection Relay: It is used in hermetic Transformers which are fully close to Atmosphere. It is used in Transformers which have a power of 630 KVA and over. These relays are the only ones which contain oil level indicator, temperature indicator, Buchholz relay and additionally and as extra pressure relay.

6. Coil Temperature Thermometer: It is used in Power Transformers. It gives temperature occurring in coils in line with current temperature relation depending on current passing through the coils. It emits either alarm or opening signal depending on set temperature value.