Wiring-distributing device: principles of electrical safety

The input-distributive devices (VRU) are intended for connection of internal electric networks and electrical installations to external power supplies and high-voltage cable lines. But the main functions of these devices are the following: distribution (which is inherent in the name of the unit) of incoming electricity between separate consumers and protection of the lines from overloads, short circuits and other similar troubles.

In other words, the input-distributing device also serves to ensure the electrical safety of high-voltage objects and equipment. This is the most important function of ASP. In addition, such a switchgear delineates the responsibility for the operation of high-voltage lines between the staff of the city's power grids and the consumer, as it is immediately possible to understand who is responsible for the accident or equipment failure. And all because the input-distributing device serves as a kind of watershed, this kind of border, on the one side of which is the consumer's responsibility zone, and on the other hand, the employees of the city electric networks. This approach is also a kind of guarantee for the uninterrupted power supply of a large number of autonomous consumers, including not only residential apartment buildings, but also large enterprises that require large capacities and stable operation of equipment.

For power supply using a single cable of small-capacity electrical installations that belong to the third category of power supply continuity, it is advisable to use a three-pole input / distribution device of the BPV type, designed for a current strength of one hundred to three hundred and fifty amperes, with one safety block and a switch. To ensure the stable and stable operation of such equipment, sometimes use the distribution boxes of the YAZ700 series equipped with a three-pole automatic switch and rated for currents of 500-600 amperes.

For power supply of residential buildings up to five floors, an input and distribution device of the type ШВ is installed. Of course, high-rise residential buildings, public buildings and small-scale enterprises require absolutely different capacities. At such facilities, as a rule, ASPs are used, which are designed in the form of single or double-sided maintenance switchboards . Any device of this type consists of an input and a distribution panel. It can also be a factory-built cabinet.

In general, there are countless number of different models of such devices, since in almost all large cities the electrical installation companies develop their own design solutions, produce their models and series of ASU. Often taking into account the specifics of a particular facility, where this equipment will be used.

For large plants and enterprises that differ in the consumption of colossal power capacities, there are provided input-distribution cabinets of the SHCHO-70 series. They are also used in energy-intensive facilities such as substations. Devices of this type, designed for power exceeding 0.4 kW, are equipped with special knife-switches with fuses or AVM and A37 series automata. Structurally, they can consist of separate blocks assembled at the installation site. Panels of such devices are installed directly at the walls of electric rooms and are serviced from the front side. The electrical boards themselves, in accordance with safety requirements, should be located in a convenient place, where only employees serving them have free access.

It is not allowed to pass gas pipelines and other utilities through such premises. In some cases, installation of such high-voltage equipment in corridors, on staircases is permitted. But at the same time the cabinets must be securely locked, and the control knobs should not be pulled out or they should be removed. It is inadmissible to install such devices in rooms of high humidity, as well as in areas prone to flooding.