Fields of Operations

Construction of Power Lines

Development, revitalization and maintenance of high voltage power transmission lines are the both nationally and internationally recognised strategic business divisions of MVM OVIT Zrt., a company having over six decades of professional experience and still being a prominent player in the market.


Besides the designing of high voltage overhead line networks, the design engineers of MVM OVIT Zrt. undertakes to prepare preliminary or detailed feasibility surveys, identify alternatives upon route analysis, to carry out the arrangement of permission procedures, to implement preliminary diagnostic surveys of complete reconstructions, and to prepare execution plans and as-built drawings.

The Company has comprehensive professional experiences and several references in the following fields: replacement of insulators and fittings, changing cable, OPGW, ADSS cable exchange, and the designing of diverse standardising works or provisional pylon solutions (disturbance, standardisation) planning.

Construction of New High Voltage Power Transmission Lines

Since its establishment, MVM OVIT Zrt., by means of its transmission line construction and installation activities, has served as a prominent background to electric power system implementation in Hungary. As a contractor, MVM OVIT Zrt. has acquired recognised professional rank and excellent national and international references in the field of constructing altogether some 10,000 kilometres of 35, 120, 220, 400 and 750 kV overhead lines, as well as in the development of installation and maintenance technologies.
The Power Line Business Management of MVM OVIT Zrt. Power Transmission Network Directorate has one of the largest transmission line construction and installation capacities in Central and Eastern Europe, which is supported by advanced devices and continuously improved technologies, engineering service, and agricultural damage appraisers as well as certified sub-contractors meeting actual market demands.

Maintenance of Existing Power Transmission Lines, Repair or Replacement of Structural Units Either on Dead or Live Circuits

The experts employed by MVM OVIT Zrt. have several decades of professional experience in the field of high voltage transmission line maintenance and repair. Following the performance of condition survey, proposals are made – with the consideration of the principle of cost minimisation – relevant to the maintenance works to be implemented, the cycle time thereof, the special repair works, the structural units to be replaced and to fittings. As a complex service – after the diagnostics are done – the experts are at the client’s disposal with designing, the provision of materials to be built in, the implementation of maintenance and repair works, as well as the documentation thereof. For the case of difficulties with disconnection, MVM OVIT Zrt. has complex, own-developed technologies for the execution of interventions during operation. When trees are to be cut to provide an alley for the line, high performance machines are used for crushing the boughs.

Troubleshooting in the case of Power Transmission Line Breakage

For those operating transfer and mains networks, MVM OVIT Zrt. maintains a uniquely effective and complex after-hours-service. As a part of this service, the regionally organised work teams – upon request – are able to start identifying the location of failure, to secure the site and to examine the fault on any part of the country immediately. Following swift evaluation of the data collected on the site, the experts make proposals without delay for the repair methods to be applied and for the materials and technologies to be used.

The experts carrying out the implementation are able to start restoration immediately relying on the specific storage base and device pool (special high performance machinery, provisional pylons, etc.) – if necessary, under control of foremen specialised in designing and technology.

Reconstruction, Standardisation, Splitting

Complex or partial reconstruction of functioning transmission lines is a business activity of MVM OVIT Zrt. with a year by year growing importance.

The experts of the transmission line business unit – upon request – will prepare execution plans and develop technologies following the performance of the condition survey and diagnostics relevant to the work stages requiring reconstruction, and make proposals for the materials to be used and the know-how to be applied.

In accordance with the contract concluded on the basis of a particular Customer’s demands – MVM OVIT Zrt. will perform the required intervention in compliance with the specifications of the Integrated System of the company. The design engineers of the company have been involved in the development of a great number of renovation technologies (for instance, the corrosion protection of Korell-steel pylons, renovation of concrete bases, etc.).

The construction of new industrial parks, motorway projects, electricity supply of railways, other agricultural or industrial facilities, in several instances require the standardisation, the alteration of the route or relocation of the existing transmission lines.

The division undertakes the execution of turnkey projects as a complex service (line permit procedure, designing, implementation, as-built drawings).

Erection of Temporary Transmission Line Pylons

The fundamental interest of every service supplier is to enhance the service reliability of transmission lines, to mitigate inevitable and planned no-voltage periods, consequently the minimization of direct losses on both the supplier’s and the customer’s sides. To ensure uninterrupted electric power supply the design engineers of MVM OVIT Zrt. have developed a collective structure and technology group, with the application of which, continuous operating of the transmission line can be ensured for the time of any work execution on a particular section of the transmission line.
The provisional pylons for transmission lines, which can be reused several times any in a versatile way, were designed and produced by MVM OVIT Zrt. in versions 120, 220 and 400 kV, and the mechanical characteristics of such pylons were tested with the participation of the Budapest University of Technology by way of large sample measurements, and in many cases involving disturbance or scheduled reconstruction, it is regularly applied in practice.

Construction of Optical Cable Network

Optical cables are the signal carriers of modern data transmission systems. The advantage of optical cables compared to traditional cables is that data transmission is not interrupted either by electric or magnetic interferences.

MVM OVIT Zrt., with its great professional experience in the field of constructing electric overhead-line networks, has taken and will take significant part in the construction and continuous expansion of optical data transmission main lines in Hungary.

With the available pool of special machinery and devices, thoroughly developed technologies and adaptive designing, installation and measurements required for implementation, MVM OVIT Zrt. undertakes the complete execution of optical data transmission cable installation both on in-service and new transmission lines (with the installation of OPWG integrated in protective conductor, or metal free self-carrying ADSS cable types).

Construction of substations

Substation construction is one of the traditional, basic business activities, an important strategic business line of MVM OVIT Zrt.

Field of activities and services:

  • Construction of high- and medium-voltage substations
  • Performance of partial works of substation construction: design work, architectural construction, electrical technological installation and commissioning activity
  • Reconstruction, extension of substations, replacement of primary and secondary devices
  • Design, construction and commissioning of the electrical equipment of power plants
  • Maintenance, troubleshooting at substations and in power plants
  • Diagnostics (transformers, primary devices, protection and control engineering equipment etc.)
  • Complete installation of electrical technological cabinets, manufacturing of distribution devices.

Construction of high- and medium-voltage substations

MVM OVIT Zrt. is ready and able – on the basis of the high-level preparedness and well-founded market knowledge of its specialists – to completely implement in green field, in main contracting framework, high- and medium-voltage substations, from the design work to commissioning. During this business project it makes an advantageous use of its ancillary and supplementary capacities developed consciously and expediently in the course of time (transportation, manufacturing, telecommunication, specialised services). Complying with the demands of the clients, it ensures the procurement, installation, commissioning, maintenance and troubleshooting of the most up-to-date equipment and electrical devices to be found on an international level.

Accomplishment of substation construction partial works


The basic task of the substation planning is to provide designs necessary for the construction works, for the building and fitting activity.

The majority of the work covers designing services for the construction, extension and maintenance in the area of the transmission network, the high- and medium-voltage distribution network. The major special planning areas can be divided into the professional fields of: architecture, primary, secondary, and within this latter, the protection, control engineering, telecommunication, account metering, installation and property protection.

The planning division prepares the schematic, construction, product and as-built designs with the newest computer design software in the form of technical descriptions, layout plans, current path and installation blueprints, schedules of materials and lists.

Substation architecture

The construction activity of MVM OVIT Zrt. is one of the important services of the company, dynamically developing from the beginnings of the 90 s: the company is able to implement all the civil engineering, foundation, reinforced concrete installation, master building and craft works from the geodesic works to the technical handover. It is the main contractor of turnkey, green-field investment projects, but undertakes to perform partial activities as well.
The construction works of MVM OVIT Zrt., both accomplished and those being just in progress, are in a considerable part constructions, renewals, extensions associated with the national high-voltage transmission and/or main distribution network, but it makes use of its capacities in the framework of other assignments as well e.g. construction of the traction substations of the railway companies (MÁV Zrt., GYSEV Zrt.). The construction activity of MVM OVIT Zrt. is built on the available, highly qualified staff of specialists and on the fleet of up-to-date prime movers, devices and tools, as well as on the knowledge base of several decades.

Electrical technological installation

MVM OVIT Zrt. is able to perform – as a part of its substation construction strategy activity – all the work phases in the electrical technological installation of the high-voltage substations, the industrial facilities such as the installation of different distribution, protection and control engineering cabinets, primary and secondary equipment, cabling of devices, installation of primary devices and transformers, construction of cable trace, drawing out and connection of cables. In this professional field it has undertaken to perform complete or partial activities with much practice for a long time.

In addition to the electrical distribution network, the Company is present and takes part in the installation of low-, medium- and high-voltage systems of industrial objects. The integrated system of design, implementation, commissioning, operating, maintenance and troubleshooting works in this respect too.

Special service providing and commissioning activity

As a part of its complex activity in substation construction, the technicians of the specialist services performs the assembly and configuration of the protection and control engineering systems, the on-site commissioning of primary and secondary equipment meeting the special demands of the clients from the preparation of offer through the design work to commissioning. The specialists, well-versed in the secondary engineering, feel at home not only at the power transmission network stations of the Hungarian electric energy system, but also in the area of the different power suppliers, railway traction substations, power plants and industrial plants, where in the course of the commissioning operations they have proven their preparedness and expertise in innumerable cases.

Reconstruction, extension of substations and industrial facilities, replacement of devices

The foolproof operation of the high-voltage transmission and main distribution network stations built decades ago requires the replacement of the high-voltage devices (primary reconstruction) with up-to-date reliable devices, the secondary reconstruction as it is termed, in the course of which the substation protection and control engineering system must be revamped.

As a contractor, MVM OVIT Zrt. performs with serious expertise and great accuracy the reconstruction of the working substations and the various industrial facilities, during which the individual phases of the reconstruction have to be implemented generally by a very close deadline and commissioned in accordance with the disconnection plan.

Design, construction, commissioning of the electrical equipment of power plants

MVM OVIT Zrt. performs continuously – with the efficient and coordinated participation of the specialists of the professional fields of substation construction and power plant maintenance – in power plant environment complete electrical and mechanical design, construction and maintenance tasks. This activity covers starting from the high-voltage de-supply of power plants, to the installation, commissioning and maintenance of the various low-voltage devices, for example turbine controllers, fire protection systems, motors, pumps, control engineering PLCs and other low-current equipment.
Our main clients: MVM Paks Nuclear Power Plant Ltd., MVM GTER Zrt., Tatabánya Heating Power Station Kft., Miskolc Heating Power Station Kft., etc.

Maintenance, troubleshooting in substations, power plants and industrial facilities

MVM OVIT Zrt. performs – besides the construction of substations – considerable maintenance services on the high-voltage transmission network, on the main distribution network of power supply companies, in power plants and major industrial plants.

The regional substation construction plants have a significant staff a specialists, devices, machines and measuring instruments for the high-level performance of the maintenance tasks covering the substation devices, which are associated with continuous teaching and training activity.

During the maintenance of the conventional devices the substation specialists of MVM OVIT Zrt. use up-to-date measuring and diagnosing equipment, hereby the time spent on maintenance becomes considerably shorter.

From the diagnostic tests of the up-to-date “maintenance-free” devices the operator can determine a maintenance conforming to the condition of the devices. The maintenance depending on the condition is accomplished by our specialists possessing much experience by means of high technical level diagnostic device stock, maintenance software (for storing the data).

Maintenance services:

  • Maintenance, diagnostic testing of High/High, High/Medium-voltage, HKV, auxiliary transformers and regulators
  • Handling, conditioning the oil of transformers
  • Diagnostics and maintenance of high- and medium-voltage substation devices (breakers, isolators, measurement converters)
  • Maintenance of high- and medium-voltage SF 6 gas- and air-insulated armour-clad equipment
  • Maintenance of medium-voltage built devices with cells
  • Renewal, revision in workshop of high-voltage devices (breakers, isolators)
  • Replacement of isolating drives and insulators
  • Maintenance of secondary systems (protection and control engineering etc.)

In respect of the transmission and main distribution network MVM OVIT Zrt. operates an incomparably efficient, complex inspection duty system. As a part of this, our regionally organised working groups can start practically at once – in any area of the country in consideration of the time of travelling, the localisation of the fault, putting the site at disposal and the survey of the fault.

After the quick evaluation of the on-site data the experts make proposals without delay for the repair methods to be applied, for the materials and technologies.

The specialists performing the implementation start the restoration at once by relying on a special warehouse base and fleet of devices (special high-duty working machines, provisory columns, standby devices etc.) – with design, technology site management, if needed.


The complex knowledge of the condition of the electrical equipment shall be a precondition for its economical and foolproof operation.

The electrical diagnostics is advantageous, because it ensures the up-to-date knowledge of the condition, the early recognition of the potential failure, the capability of preventing the losses due to operating troubles, the ability to plan the intervention necessary, but sufficient at the same time, that is of the condition-dependent maintenance, ensuing from this the possibility of operation at minimum cost.

Our colleagues participate on an international level in the development of the most modern diagnostic methods and in the introduction of their practical application; due to the CIGRÉ membership and relationship.

MVM OVIT Zrt. offers complex diagnostics, the components of which are as follows:

  • Measurement and evaluation one-by-one corresponding to the peculiarities of the individual electrical equipment, as well as complying with the relevant regulations and standards
  • Application of diagnostics combined — accredited in certain cases — according to need, demand and possibility (e.g. insulating oil error gas analysis (HGA) and thermo-vision).
  • Individual and complex expert evaluation, condition survey

The guarantees of the diagnostics performed by OVIT are the quality system operated since 1996, the accredited status of certain activities, provision for the continuously calibrated condition of all the designated measuring devices, performance, customers’ audits, performance of parallel and comparative measurements, as possibility permits, with national and international laboratories, up-to-date stock of instruments, trained, experienced, professionally recognised measuring personnel.

Our diagnostic services:

  • Insulating oil test, HGA — accredited service
  • Heat mapping
  • Measuring transformer calibration — a service shared with the Hungarian Trade Licensing Office
  • High-voltage measurements
  • Electricity consumption metering
  • Maintenance and diagnostic activity of transformers
  • Complex diagnostics, preparation of expert opinion

Contact information:

Diagnostic Plant

Telephone: (+36 27) 530 451

Fax: (+36 27) 530 450


Preliminary installation of electrical technological cabinets, manufacturing of distribution equipment

The specialists of the Substation Business Management of MVM OVIT Zrt. have a great experience in the installation, maintenance and repair of the high-voltage substations and industrial facilities. The optimal selection of the built-in devices and equipment means a guarantee at all times for the reliability and quality of the company’s activity.

The MVM OVIT Zrt. began in 1998 – as a result of several years’ development work – the serial production of up-to-date low-voltage auxiliary equipment as well. The preliminary installation and quality inspection of the protection and control engineering cabinets of the alternating and direct current low-voltage switching and distribution devices meeting the demands of today are carried on in the the Central Substation Construction Plant on the basis of the plans of the Department of Substation Design and Technology. All the complete units possess MEEI type testing certificate dated 31. 12. 1997. In addition to the aforesaid, MVM OVIT Zrt. holds licences for the installation of distributor type families of various makes, using them not only in substation-environments but also in industrial environments. This ensures that the Company’s installation capacities are utilized at an optimum level.