AZ Elektrostav a.s. Construction of electrical and optical telecommunications apparatus from A to Z

The joint stock company AZ Elektrostav was founded in 1992 as a company carrying out assembly work on constructions of electrical wiring systems. From its initial 30 employees, the firm has grown into a company with 100 core employees and several dozen external workers. The range of services on offer was gradually expanded, in order that the company might realise its credo of carrying out constructions of electrical and optical telecommunications equipment from A to Z, i.e. from planning through purchase of components and implementation of constructions to inspection and maintenance of the apparatus. Within the company, emphasis is placed on quality of manufacture, which is testified by the fact that the quality management system of all of AZ Elektrostav’s activities is certified according to the EN ISO 9001 international standard..

AZ Elektrostav is based at Nymburk (see fig. 1), a city situated on the banks of the river Labe, about 50 km east of Prague. This central location, with excellent rail and road communication, allows Elektrostav to develop its activities efficiently throughout the whole of the Czech Republic and to carry out large assignments for neighbouring countries as well. AZ Elektrostav applies most of its capacity in construction projects for electricity, particularly at the level of medium (15 to 35 kV) and very high voltage (60 to 400 kV). The company not only assembles medium voltage systems, but also manufactures important components for it, such as steel pylons and other structures for external cable lines (fig. 2). The vast majority of its structures are supplied with hot-galvanised surface treatment. In the field of locksmith manufacture, AZ Elektrostav offers a wide choice of products. For its medium-voltage assembly work, AZ Elektrostav has workers qualified for all related activities, such as work on cable fittings and switchboards of all renowned manufacturers. It also has the necessary technology at its disposal (hydraulic pressing apparatus, measuring devices etc.). The same applies to constructions of electrical lines at the highest voltages. The company is able to manage the construction of heavy lines (figs. 3 and 4) at voltages of up to 400 kV. AZ Elektrostav is one of the most important suppliers in the Czech Republic in the field of assembly work using composite ground cables (OPGW).For this activity, the company is equipped with top-grade technology which allows it to carry out the most demanding technological procedures. For assembly, it uses hydraulic puller-tensioner (fig. 5) which are equipped with devices for regulating and recording the forces applied. The company also carried out difficult joining and measuring of conductors using glass fibres. For these operations it uses top-class welding units and instruments for measuring OPGW by the direct and indirect methods (fig. 6). Owing to its ability to provide services quickly and comprehensively, AZ Elektrostav was selected to take charge of the servicing of optical telecommunication lines at a number of electricity companies operating networks on the basis of OPGW. AZ Elektrostav also accepts orders in the range of terminal telecommunications apparatus (especially with a view to OPGW) and in the field of industrial installations (fig. 7), where it provides assembly of new apparatus and maintenance on the basis of service contracts... AZ Elektrostav is able to plan everything it is able to build. The quality and effectiveness of its planning activity is supported in particular by computer technology (fig. 8) and by strong feedback between its assembly and planning divisions.

In 1994, together with Støedoèeská energetická a.s., AZ Elektrostav established Eltraf a.s., a company which manufactures kiosk transformer stations and switchboards for voltages ranging from 20 to 35 kV/0.4 kV. Thus AZ Elektrostav substantially improved its capacity for speed and comprehensiveness in its supplies. Eltraf a.s. Kralice manufactures a varied assortment of apparatus for electricity distribution, especially kiosk transformer stations with an input voltage of between 20 and 35 kV and an output voltage of 0.4 kV. The basic material for the transformer station frame is high resistance Aluzink, specially alloyed steel plate whose surface is covered with an alloy of aluminium, zinc and magnesium. This material's excellent resistance to corrosion (several times higher than hot galvanised metals) is demonstrated by the fact that transformer stations made of this metal have now been successfully used for several decades in a variety of demanding climactic conditions (Saudi Arabia, oil fields in the North Sea, suspended under bridges linking Denmark). Recently this metal has been used by reputed car manufacturers for the parts of the bodywork most subject to wear, especially on freight vehicles. There are two basic ranges of transformer station. The first has an Aluzink frame, whilst the second uses Aluzink only in the surface part, whilst the underground part consists of a concrete tub (a monolithic high frequency vibrated concrete cast). The transformer stations can be delivered both with input voltage switchboards with atmospheric instruments (fig. 9), and with instruments on the basis of SF6 (fig.10).

Owing to the technology that is used, the form of the transformer stations can be modified according to customer requirements. Different versions are available in colour (facade colour or plaster is usually applied), shape of roof, and material used for application of covering (wood, ceramic etc.) and roof (shingle, tiles etc.) if appropriate. Some of the possibilities are illustrated in figs. 11 to 13. The advantages of these transformer stations (small dimensions, low weight, speedy delivery, conformity to ecological requirements, complete suppression of electromagnetic field, easy assembly and adaptability, long life) have resulted in their sales being extended to transport infrastructure building projects. These transformer stations are very frequently used on railways (see fig. 14). High-voltage switchboards for kiosk transformer stations are manufactured at AZ Elektrostav (fig.15). The form and setting of these switchboards depends on the wishes of the customer. AZ Elektrostav also manufactures other components for electricity distribution, including a range of low-voltage switchboards (figs.16 and17), which can be used for any pylon transformer stations (e.g. fig.18) or other applications both indoors and outdoors. Other products include housings for electricity measuring units (see figs. 19 and 20) and for special measuring devices (fig. 21). Here. too, emphasis is laid on resistance to atmospheric influences (again housings are made from Aluzink, and the other components from resistant plastics). AZ Elektrostav operates a modern line for applying thermoreactive (powder) colours. This also serves to increase the quality of its products.

To ensure the smooth running of its assembly units, AZ Elektrostav provides road transport, and service of mechanisms, automobiles and freight transports (fig.22).