Specialies construction work that is performed during the erection or reconstruction of buildings or structures intended for various purposes and that entails the installation of electric wiring and electrical equipment. The electric wiring may be overhead power lines, cable lines, current leads, or interior wiring. Examples of electrical equipment include electric machinery, distribution centers, and control consoles. In the USSR, electrical installation work is usually carried out in two stages.
The first stage, which coincides in time with general construction work, includes the installation of fasteners or inserts in structural elements for the subsequent attachment of electrical equipment and structures for the installation of electric wiring. It also includes the installation of conduits for electric wiring in the foundations and floors of buildings or structures and the installation of wall sockets for outlets and switches. In the first stage, the preassembly of electrical equipment and wiring structures, the fabrication of conduit sections, and the board lacing of wires and cables for lighting and other circuits are carried out away from the construction site in specially equipped electrical-installation prefabrication shops.
In the second stage, the electrical equipment and the structures for the installation of wiring are transported to the construction site, installed in the planned locations, and assembled. In addition, cables and wires are laid and are connected to the installed electrical equipment. Electrical installation work is completed when the installed equipment is actuated and adjusted. The most complicated work in this respect is the adjustment of relay protection and automatic control systems for electric drives.
Electrical installation work is mechanized through the use of general-purpose construction machinery—for example, lift trucks, hoists, and truck cranes—and of specialies electrical-installation machinery, devices, and tools.
The time required for electrical installation work is reduced and the productivity of labor in such work is raised primarily through the use of industrial methods of installing electrical equipment and through the delivery to construction sites of structures for the installation of wiring and elements of electric wiring in consolidated subassemblies and units, which are fabricated and assembled in electrical-installation prefabrication shops. The level of industrialization of electrical installation work is due in large part to the output by industry of complete sets of electrical equipment and of electric wiring that can be easily installed and adjusted.
One of the main trends in the further industrialization of electrical installation work is the use of large-scale electrical engineering facilities, for example, the rooms of electric-drive control stations and of urban transformer substations. Such facilities are delivered by industry with the electrical equipment completely installed and adjusted. In this case, electrical installation work is reduced to the installation of such facilities and the connection of the facilities to external power networks.