Joint-Stock Company Scientific and Engineering Center "ZTZ-Service Co." is located in the Southern Ukrainian city Zaporozhye, which was recognized as a "Transformer Capital" in the former Soviet Union.

Historically ZTZ-Service Co. dated from 1954, when an Engineering Installation De-partment was established within Zaporozhye Transformer Plant to provide technical supervision of the assembling, installation and testing of the power transformers for 400 kV.

Since that time practically all the Large Power Transformers manufactured by Zapo-rozhtransformator (ZTR in abbreviation) have been installed and put into operation under technical supervision of the Installation Department, future ZTZ-Service Co.

Specialists of the department were the main developers of the guiding technical documentation on installation and commissioning of 110-750 kV transformers.

Hereinafter the development of the technological equipment on drying out, oil de-gassing and purification necessary for new transformers putting into operation, tech-nologies on the transformers drying out and their moisture protection have been de-veloped by ZTZ-Service Co. into technologies of the transformer equipment refur-bishment and life extension.

In 1961-1963 the first experience on power transformer in-field reconstruction and reliability increasing was obtained.

In 1966-1971 the work on the equipment condition diagnostics, development and im-plementation of the methods on reliability increasing gradually took the central place and became the base of ZTZ-Service Co. nowadays strategy - conception of life ex-tension and guaranteed maintenance of the equipment serviceability meeting the highest international standards requirements.

Since 1991, after ZTZ-Service Co. became firstly a separate state enterprise and then a joint-stock company, the conceptual grounding of ZTZ-Service Co. became continuous development of scientific and technological base to have possibility for performance of the most difficult works: from on-line diagnostics to the guaranteed life extension of the transformer equipment.

ZTZ-Service Co. is an active member of the international organizations determining technical policy in the field of energy: since 1991 - a collective member of CIGRE, member of CIGRE Study Committee No 12 "Transformers", since 1993 - member of the international committees of the Doble Clients: "Transformers", "Bushings and in-strument transformers", "Liquid dielectrics", "Transformer oils", member of EuroDoble Committee.