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trafo company

LEMI TRAFO was founded in 1996 with a focus on the production and trade of electrical equipment. Over time, the activities expanded and the company bought a factory for electrical repairs in the industrial part of Pernik with a total area of 8,000 m2. Within a few years, the entire factory was renovated and state-of-the-art machinery for the production of oil distribution transformers was installed.

As a result of the excellent cooperation with the world-famous TMC Transformers group, as well as the growing demand for dry-type transformers, a company called TMC Bulgaria was founded with a focus on the production of dry-type transformers. To meet the needs of the new company, a new production line of 8,000 m2 was built, with new machines and a modern testing room installed.

Nowadays, LEMI TRAFO is well known not only in Bulgaria but also on the international market. It is constantly striving to strengthen its position on the European market, to expand the number of satisfied customers, and also to develop in a long-term and stable way, which is achieved thanks to an excellent team of employees. The company is well known for its fairness, quality, and its desire to meet all the demanding requirements of its clients.




Due to the high demands of clients for the quality of the transformers produced and their compliance with international trends, LEMI TRAFO applied for certification issued by Bureau Veritas - a leading and globally recognized certification organization - in order to adopt management systems. After a successful audit, we were awarded ISO 9001:2000 quality management system certification. In the following years, we also adopted the OHSAS 18001:1999 occupational health and safety management system and the ISO 14001:2004 environmental management system. As a result, we have no doubt that our customers are very satisfied with the quality of the transformers we offer.




The rapid growth of the company and the drive towards the production of distribution transformers has resulted in the need for an inspection body that would allow inspection and testing of the distribution transformers produced. To this end, an independent unit called "TRAFO Control" was created within LEMI TRAFO.
This is an independent, accredited unit dedicated to Type C inspection, which has been authorised by BAS (Bulgarian Accreditation Service) with accreditation number 142 OKC. The scope is as follows:

  • Electrical installations and equipment up to 1 000 V
  • Electrical installations and equipment up to and above 1 000 V
  • Electrical machines for alternating and direct currents up to a voltage of 1 000 V
  • Electrical protective equipment
  • Cable lines for voltages up to and above 1 000 V
  • Power transformers up to 35 kV

  • Measuring transformers up to 20 kV

  • Transformer oil




LEMI TRAFO manufactures three-phase oil-immersed distribution transformers with outputs from 25 kVA to 5,000 kVA. Our distribution transformers are suitable for indoor or outdoor installation. 50 VG - 20 ÷ 80 kPa up to 1 kV/1600 A.
We offer bulk production of distribution transformers of two types depending on the design - hermetically sealed or with a conservator. All offered transformers are in ECO Design. On client's request we can offer transformers with reduced losses.


TMC Bulgaria represents part of the TMC Transformers group, which has branches in countries such as Australia, Italy, Spain, Argentina, France, Germany and Israel. The company manufactures dry epoxy transformers ranging from 100 kVA to 10,000 kVA, which are suitable for installation in areas with high ecological and fire protection requirements. Our transformers are characterized by high reliability and quality, solid construction, long service life and low noise level. TMC Group's engineering team offers standard transformers, transformers with reduced losses, special types of transformers with specific windings according to customer requirements (traction transformers, transformers for frequency converters, transformers with double HV or LV windings).

The transformers are tested in CESI laboratories in compliance with environmental class E2, climatic class C2, fire resistance class F1. All our transformers undergo routine tests, and we also offer some special tests on customer's request.

Routine tests include:

  • Ratio measurements and phase displacement checks and confirmation of the type of wiring.
  • Loss and no-load current measurements
  • Measurement of short-circuit and load losses
  • Applied voltage tests
  • Applied voltage tests
  • Partial discharge measurements
  • Verification of documentation
  • Verification of accessories
  • Verification of dimensions

Special tests include:

  • Thermal stress

  • Impulse voltage test
  • Noise level measurement


Epoxy transformers, manufactured by TMC Group, are available according to requirements. Either with standard or additional accessories.


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