Electrical panels. Types and purpose
Surely, more than once we have seen abbreviations like: SHE, VRU, OSCH, etc. on billboards. all these intricate letters hide the essence of the devices, which is known to those who directly service them, and sometimes even those who service the switchboards become so accustomed to the abbreviation that they do not think about their purposes. So let's start looking at types and types of electrical panels from the main shield, the “king” of the shields.
The main switchboard is designed for input power lines power supply, electricity metering and distribution of power lines for objects. The device also serves to protect against short circuits and overloads in power supply networks. If we consider the hierarchy of electrical switchboards, then the main switchboard is at the very top level. The main distribution board is most often located on the territory transformer substation(TP), boiler houses, production.
The device, which includes a complex of electrical automation and structures, is used to receive introductory power cable, distribution of supply lines for ShchE, ShchK, ShchO, ASU, electricity metering, protection of lines from overloads and short circuits. Installed at the residential entrance, public buildings, as well as in production premises (shops).
The AVR panel is equipped with special automation. The automatic transfer switch switches power from the main source to an additional one (generator) in the event of a failure of the main electricity supplier. After eliminating the accident, the ATS will transfer from the generator to the main line and after a few minutes the generator will be stopped. Used in industrial, commercial, communal buildings, as well as in cottages.
Floor board (SHE).
Used in residential and administrative buildings for distribution of electricity to 1 – 6 apartments. The shield is divided primarily into three compartments:
Distribution compartment (modular automation for groups of electrical circuits).
Metering compartment (electric meters).
Subscriber compartment (telephone, intercom, TV, radio, etc.).
Apartment panel (AS).
As a rule, it is located at the entrance to the apartment in the hallway area. The main purpose of the control panel is electricity metering, distribution of group power lines in the apartment, modular automation protects the electrical circuit from overloads and short circuits. ShchK are invoice and indoor installation, metal and plastic versions.
The apartment panel is divided into:
Shchku - apartment accounting panel.
ShchKR – apartment distribution board.
Lighting board (OSH).
Lighting boards are installed in administrative, retail and office premises for infrequent operational switching on and off of automation. ShchO protects outgoing lines from overloads and short circuits.
Lighting boards are divided into:
OSHV (lighting panel with switch).
UOSCHV (recessed lighting panel with switch).
Classification and characteristics of inflorescences
According to the presence and nature of bracts (bracts):
- Frondose(lat. frondis - foliage, leaves, greenery), or leafy - inflorescences in which the bracts have well-developed plates (for example, fuchsia, tricolor violet, loosestrife).
- Bracteose- inflorescences in which the bracts are represented by scale-like leaves of the upper formation - bractaeans(for example, lily of the valley, lilac, cherry).
- Ebracteaceae, or bare - inflorescences in which the bracts are reduced (for example, wild radish, shepherd's purse and other brassicas (cruciferous).
By degree of branching:
- Simple- inflorescences in which single flowers are located on the main axis and, thus, branching does not exceed two orders (for example, hyacinth, bird cherry, plantain, etc.).
- Complex- inflorescences in which private ones are located on the main axis ( partial) inflorescences, that is, branching reaches three, four or more orders (for example, lilac, privet, viburnum, etc.).
According to the type of growth and direction of flower opening:
- Racemose, or bothric(from Latin racēmus and Greek. botrion- brush, cluster) - inflorescences characterized by a monopodial type of growth of axes and acropetal (that is, directed from the base of the axis to its apex) opening of flowers (for example, fireweed, shepherd's purse, etc.)
- Cymose(from Latin cyma - half-umbrella) - inflorescences characterized by a sympodial type of growth of axes and basipetal (that is, directed from the top of the axis to its base) opening of flowers (for example, lungwort).
- Closed, or certain - inflorescences in which the apical (apical) meristems of the axes are spent on the formation apical flower(all cymose inflorescences, as well as racemose inflorescences of some plants: corydalis, crassula, bellflowers, etc.).
- Open, or undefined - inflorescences in which the apical meristems of the axes remain in a vegetative state (lily of the valley, hyacinth, wintergreen, etc.).
Variety of inflorescences
Simple inflorescences
As mentioned above, simple inflorescences are those in which all the flowers are located only on the main axis. Typically, the inflorescences of this group are racemic.
The main version of simple inflorescences is brush- characterized by an elongated main axis and flowers on well-defined pedicels of more or less equal length. Appearance brushes can vary greatly: they can be frontal (tricolor violet), bracteous (bird cherry), frontal-bracteous (willowherb), naked (colts); open (hyacinth) and closed (peach bell); multi-flowered (Veronica longifolia) and one-two-flowered (sowing pea).
If the lower pedicels are much longer than the upper ones and all the flowers are located in the same plane, the inflorescence is called shield(garden pear).
An inflorescence with a well-developed main axis and sessile flowers is called spike(plantain, orchis, aspen).
The same inflorescence, but with a thick fleshy axis and a common covering leaf, is called cob(calamus, calamus, corn).
In cases where the main axis is greatly shortened and the flowers are located on developed pedicels of equal length, umbrella(breaker, celandine, primrose, cherry).
If the main axis is shortened and the flowers are sessile or the pedicels are poorly developed, the inflorescence is called head(clover, alfalfa, adoxa).
The most specialized variant of simple inflorescences is basket- characteristic of representatives of the extensive family Asteraceae (Asteraceae), some umbelliferae (Engium, Sanicula), as well as bellflowers (Bug). In baskets, small sessile flowers are densely located on the surface of the flat or cone-shaped axis of the inflorescence. From below, the axis of the inflorescence is surrounded by an involucre, which is represented by vegetative leaves of the upper formation.
Asteraceae are characterized by three types of flowers: reed, pseudolingulate And funnel-shaped, - which can be distributed in the basket in various combinations. The appearance of the baskets imitates that of single flowers: the involucre is similar to the calyx, the bright peripheral flowers are similar to the corolla. Such highly specialized inflorescences, resembling a single flower, are called anthodia(ancient Greek anthos - flower).
Complex inflorescences
Complex inflorescences are those in which the main axis contains not single flowers, but partial (private) inflorescences.
Complex racemose inflorescences
Double brush- complex inflorescences in which axillary simple racemes are located on an elongated monopodial main axis. They are characteristic of plants of the Moth subfamily, some species of the genus Veronica, etc.
Close to double brushes complex umbrellas, characteristic of plants of the Umbrella family, as well as complex ears, characteristic of cereals (wheat, rye, barley). In these variants of complex inflorescences, partial simple inflorescences received the name umbrellas And spikelets.
panicles differ from double racemes in more abundant branching and in the fact that their lower partial inflorescences are developed and branch much more strongly than the upper ones; as a result, typical panicles have pyramidal shape (lilac, privet, paniculata hydrangea, etc.). There are also other forms of this inflorescence. Thus, with a strong reduction in the number of partial inflorescences and a sharp depletion of the upper ones, the panicle becomes thyroid(viburnum, elderberry, rowan, etc.). If the central axes of the lower branches greatly outgrow those of the upper ones, cup-shaped panicles, like, for example, meadowsweet.
In addition to those listed, there are a number of other types of inflorescences in which the branching characteristics of the main axis differ from those of the branching of partial inflorescences. They are sometimes called aggregate. For example, panicle of umbrellas- paniculately branched inflorescence bearing simple umbrellas on the terminal axes (high Aralia and Manchurian). panicle of baskets- paniculately branched inflorescence bearing partial inflorescences - baskets - on the terminal axes. There are also basket brush(the string is drooping), ear of baskets(forest dried grass). Other types of aggregate inflorescences are also possible.
Complex cymose inflorescences
Cymoids- these are complex inflorescences with sympodial growth, in which the main axis is not expressed. They are divided into three main variants: dichasia, monochasia and pleiochasia, depending on how many lateral branches replace one parent branch during sympodial growth.
Dikhazia called cymose inflorescences, in which each axis bears two axes of the next order. The daughter axes here appear at the top of the mother axes and outgrow its top. If the lower sections of the axes (up to the bracts) are greatly shortened, the dichasia takes on the appearance of an umbrella (indoor geranium, umbelliferous osseous); sometimes such inflorescences are called false umbrellas or multi-rayed arachnids. In the case of complete reduction of the axes and crowding of a large number of dichasias, inflorescences with the appearance of a basket are formed (bark, blueberry and other teasel). Dichasial umbrellas and baskets differ from simple ones in the nature of flower blooming (centrifugal/simultaneous and centripetal, respectively).
Monochasia- such cymose inflorescences in which each mother axis carries only one daughter. As in Dichasia, the daughter axes here are located in the upper part of the mother axis and outgrow its apex. In the phase of flowering and ripening, monochasia fruits resemble brushes or ears. Monochasia is divided into convolutions And curls.
Curl- cymose inflorescence ( complex inflorescence, growing sympodially), in which another axis with a single flower departs from the main axis with a single flower, and from that - a third-order axis, and so on, with all flowers directed in one direction. This type of inflorescence is characteristic of plants from the borage family: for example, lungwort ( Pulmonaria), comfrey ( Symphytum), forget-me-nots ( Myosotis) .
If flowers of higher orders appear alternately on the right and then on the left in relation to flowers of lower orders, then such an inflorescence is called gyrus(borage, petunia, etc.). In the phase of flowering and ripening, monochasia fruits resemble brushes or ears.
Often in cymose inflorescences, flowers of the first and second orders are located in dichasia, and flowers of the third and higher orders form monochasia. This is how widespread double convolutions(norichnik, forget-me-not, comfrey) and double curls(St. John's wort).
Pleiochasia called cymoids, in which each mother axis is replaced by several more or less whorled daughter axis, outgrowing its apex (some types of buttercup, elderberry).
The genus Euphorbia from the Euphorbiaceae family is characterized by a special type of cymoid anthodia - tions(cyathium). The cyatium consists of an apical pistillate flower and five stamens, which arose as a result of the extreme reduction of the five staminate partial inflorescences. The cyatium is surrounded by an involucre consisting of bracts, again reduced partial inflorescences.
Thyrsus- a complex inflorescence with a monopodially growing main axis and lateral private cymoid inflorescences. Thyrsae are widespread, they are characteristic of representatives of the families Lamiaceae, Borageaceae, Norichniaceae, etc.
Pyramid panicle
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Electrical distribution boards
are devices of various configurations that are used to transmit incoming electric current into several smaller circuits and provide various protections to the internal connections: for example, overcurrent and overload protection in the form of fuses or circuit breakers, from influences environment- snow, rain, dust, etc., and also protect users from death and injury associated with electric shock. This may be a large single panel or assembly containing cable connections, switches to redirect power, transformers, contactors, relays, insulators, fuses, and other protection and control devices.
Electrical panels are known by different names such asdistribution board, cabinet or box, electrical or panel board, etc.., and use different abbreviations to indicate their purpose - ShchO, ShchK, Main Shch, ShchE and another. These are a kind of centers that receive large incoming current from the mother electrical network, for example, from a power plant or generator, and disperse it to smaller consumers - substations, workshops, houses, apartments.
As a rule, they are mounted on a wall inside or outside a building or in free-standing boxes and are protected by durable housings with closing doors with an abbreviation printed on them - the name of the shield, defining its purpose, and warning signs. Some boards are designed for one family or apartment building, while others are for commercial buildings and industrial facilities. The hierarchy of switchboards begins with their “boss” called main switchboard - main distribution board.
Main switchboard
You are unlikely to meet him in the residential sector, unless it is autonomous house, powered by powerful generator. Its usual “habitats” are transformer substations and boiler rooms. This shield - the most powerful at any facility - can receive a current of several thousand amperes, converting it and supplying it in the required quantity to several lines diverging throughout workshops or houses. Between the “boss” of the main switchboard and the end consumers there are the ASU - the input switchgear - and various small panels - ShchA/ShchU/ShchE/ShchK/ShchO and others.
Input distribution device
It contains numerous cables with a whole arsenal of meters, functional boards, defense mechanisms, saving networks from excessive loads, equalizing voltage, stabilizing the current supply, measuring electricity parameters, etc. ASU processes incoming data in its own way main switchboard electricity and directs it further through small switchboards for distribution among floors, apartments, automation systems, alarms, control, management, etc.
Floor shield
This closed cabinet is often made with a transparent window and is located, as the name suggests, on the floors of apartment buildings, receiving current from ASU and sending him to his apartments. The box, as a rule, contains cables, electricity metering devices, circuit breakers and various devices for protection against power surges, and sometimes some devices for servicing Internet networks, cable television, etc. In many residential buildings SHE is absent, and the duties of receiving and distributing energy are performed by his apartment colleague - ShchK.
Apartment board
Modern building and electrical standards allow for a variety of options ShchK, using combinations different schemes for several user tasks, for example, metering consumed electricity and distributing it separately in a line with power sockets and lighting, fire alarms and security systems.
Lighting boards
SCHO may include conventional circuit breakers or (in rare cases) residual current switches, relays, sensors, fuses, power meters andRCD. They are installed mainly where there is a need to manage from one place in large groups lighting fixtures, for example, turning off all lighting in hypermarkets, office premises, workshops or floors. Most PopularUOSCHV- recessed lighting panel with switches - is a neat looking panel built into the wall with a door and a row of circuit breakers underneath it.
Emergency transfer panels
Devices such as ShchAP and AVR (automatic input backup power), perform similar functions - automatic switching to backup source energy, for example to another line or generator in case emergency shutdown electricity or a sharp drop in network voltage, maintaining the necessary power supply parameters until the problem is resolved. They are usually installed where it is vitally important uninterruptible power supply.
Control and automation panels
SHU and SHCHA provide controlled power supply to lighting, ventilation/heating, security and fire alarm or used, for example, for remote control electric motors. Here you can find various switches, buttons and lights in the form of indicators that allow you to monitor the operation of systems and individual devices. In the first option, control is carried out mainly manually, while the second does everything automatically based on data from various sensors and controllers or working according to a given program.
We only talked aboutthe most common types of electrical panels, while in fact there are many more of them, intended to solve some specific tasks. For reasons of aesthetics and safety electrical panels and panels inside residential buildings, as a rule, are located in remote places - in attics, garages or basements, but sometimes they can also be an architectural part of the building. All safety panels have a closed front part and are installed so as to be easily accessible for monitoring and maintenance. Building codes and the rules prohibit the installation of panels in the bathroom, in wardrobes or where there is not enough space for an electrician seeking to access the panel. Specific situations, such as outdoor installations, fire or explosive environments, or any unusual locations, may require demand special equipment designed to withstand harsh environments and more stringent installation regulations.
Commercial network "Planet Electric"has wide range low voltage equipment from NEMZ
Electricity, reaching the consumer, goes through many stages. Among them are such stages as generation and transportation of electrical network lines. Before reaching the consumer, electricity comes to electrical panels, where electricity is distributed, and a protection system is installed. emergency situations associated with overloads and short circuits.
Such boards are used to organize the infrastructure of buildings industrial production, residential buildings, public spaces. An electrical panel of a certain type is installed depending on the purpose. There is a wide selection of options and models of such devices on sale, which have their own differences in content and form.
Purpose
In a simple design, electrical panels serve to create a network that powers lighting devices, household appliances, sockets, etc. The range of electricity consumers is constantly expanding, so a more complex model may be needed that allows you to create a division of energy into groups. These are already devices with great energy switching capabilities. They work with different categories of stationary electrical appliances.
To determine the tasks that electrical panels perform, it is necessary to take a closer look at the organization of energy supply. One panel can supply electricity both to an individual apartment and to the building as a whole. In this case, the shield controls the electricity that is supplied to different distribution devices, covering other local service areas.
Kinds electrical panels
There are different classes of electrical panels. They divide their designs primarily by intended purpose. This type of equipment, such as electrical panels, can provide electricity to one apartment or several different energy consumers.
Shields are also divided according to installation method and material of construction. According to the first factor, the most popular are conventional hanging and wall structures. Electrical panels that are built into a wall niche are very convenient to use. But the installation of such a shield is not always suitable for the location conditions.
If we consider the materials from which electrical panels are made, then most often manufacturers combine several materials, for example, metal with plastic. Metal shields have proven themselves to be reliable, time-tested structures. However, new materials and composites that have appeared in Lately, no worse than metal in terms of durability and strength, and in some ways even surpass it. There is no significant difference between electrical panels from different materials not available.
To better understand the purpose of electrical panels in the network, consider their hierarchy by type, type and subtype.
Main switchboard
This switchboard (MSB) is used to enter power supply lines, distribute electricity to various objects, and also account for electricity. In emergency situations, it protects against overloads and short circuits in electrical networks. In the hierarchy tree, the main switchboard is located at the very top. The main switchboard is usually located at the transformer substation site, either in production or in the boiler room.
Input switchgear
This device (ASU) is used to receive network power from the power cable, and further distribute electricity along the power lines of electrical panels lower level, as well as for accounting for energy consumption, protection against short circuits, overloads during accidents. It includes a system of structures and electrical automation. The incoming electrical panel is usually located in production workshops, at the entrance to buildings public organizations, residential buildings.
Emergency transfer of reserve
Backup input panel (AVR)
equipped with special automatic devices that switch power in the event of an emergency from the main source to a backup source of electricity. After eliminating the causes of the emergency mode, the ATS reconnects the main power source to the line. It is used in many places: communal buildings, cottages, and production.
Floor electrical panel
Electrical panels on the floors of buildings (SB) serve to distribute the supply of electricity to apartments on the same floor.
The shield is usually divided into 3 compartments:
- Distribution compartment (automatic devices for consumer groups).
- Accounting compartment ().
- Subscriber compartment (radio, television, telephone).
Apartment board
Most often, such an apartment panel (ASB) is located in an apartment near the entrance, usually in the hallway. Its main purpose is to account for the energy of electric current, distribute electricity along the lines of the apartment for power supply different rooms and for various household devices. Automatic device modules located in the apartment panel protect the network from short circuits and overloads.
Apartment switchboards are divided by type of installation:
- Internal.
- Invoices.
According to the material of manufacture:
- Plastic.
- Metal.
Types of apartment electrical panels by purpose:
- Accounting (Shchku).
- Distribution (SchKR).
Lighting board
The lighting board is located in almost all existing buildings equipped with lighting devices for rare switching of lighting equipment using the board's automation. The lighting board protects outgoing lines from short circuits and current overloads.
Electrical lighting panels are divided into:
- Lighting panel with switch (OSCHV).
- Built-in (recessed) lighting panel with switch (УОШЧВ).
Switchboard
This type of control panel (control panel) is designed to control automatic devices responsible for driving mechanisms: heating, alarms, ventilation, etc. Property values are adjusted manually.
Automation shield
This type of panel contains software controllers that monitor the functioning of drives of various mechanisms and systems.
Uninterruptible supply board
This switchboard (SBBP) provides electrical power to instruments and devices of control systems, computer technology, medical equipment, and other systems that must be provided with constant power supply, and belonging to category 1 power supply.
We have considered only some electrical panels used in electrical networks, but there are many more types.
Shield assembly
Installation work for the installation of electrical panels usually begins with the assembly operation of the main structure. There are switchboard devices in the form of assembled housings with mounting panels included. However, complete panels are more often used, and for them a design and assembly diagram are already developed.
First, the body is prepared for assembly, then the wall plugs of the body are removed. Electrical panels have different numbers of cable line sections depending on their design. Therefore, you need to calculate in advance the location and number of holes for cables and wires, taking into account the possibility of making additional holes.
Next, installation rails, grounding bars, and mounting brackets are mounted. The components of the shield may be different. It depends on the type of distribution board. But the main thing in the assembly is preparation for final installation.
Installation
The installation method also depends on the type of shield design. The main difficulty is the design of the built-in electrical panel, since it requires hollowing out the space necessary for its installation in the wall.
After hollowing out a niche in the wall, the shield is installed in place and secured with special brackets. In advance, before choosing the location of the switchboard, the possibility of access to the electrical wiring is calculated. After final installation, connect to power and consuming load.
An input cable with additional wires is installed inside the shield. The wires are aligned in one layer, taking into account the placement of circuit breakers and their configuration. When the electrical wiring is connected to all devices of the panel, then the load of consumers and electrical installations are connected. Next, all lines are turned on one by one to check the functionality of the network.
Access limitation
When operating electrical panels, electrical safety rules must be observed. They must also be performed when installing the shield. When installed in public premises provide fencing and insulation of live parts. Access to the switchboard elements is protected by locked fences.
Distribution electrical energy at all times was one of the responsible operations. The efficiency of energy consumption and the stability of power supply to consumers depend on it. Therefore, manufacturers are interested in producing reliable and functional devices, such as electrical panels.
The range of household devices is constantly growing, so distribution boards must also be modernized and expand their functional tasks. The popularity of models that are designed to arrange devices inside a switchboard for individual use is increasing.
Thus, using threaded connections, the installation panel of the switchboard can be equipped with almost any devices and modules.
Scutellum, inflorescence I
A corymb (Corymbus) is a multi-flowered inflorescence of some plants, similar to a brush (racemus), in which on the main peduncle there are several more peduncles of the second order, sequentially extending one after another, with each subsequent peduncle shorter than the previous one (Fig. 1), so that all pedicels end in flowers always at the same height. Thus, Shch. is an intermediate inflorescence between the raceme, head and umbrella. Shch is found in apple, pear, plum and some other plants. In addition to the simple shield just described, in some plants there is also a complex shield that differs from simple themes, that its second-order pedicels themselves still branch, so that on each peduncle of the Shch. there are several pedicels, in turn collected by Shch. We find such a complex Shch. in yarrow (Achillea - Fig. 2), chastuha and other plants . Shch is also called the cotyledon of a cereal grain, adapted for absorbing water from the soil, and therefore remaining in the ground during grain germination. I.L.S. (Corynchus) - see Inflorescence.
Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron. - St. Petersburg: Brockhaus-Efron. 1890-1907 .
See what “Scutellum, inflorescence” is in other dictionaries:
Inflorescence (lat. inflorescentia) is part of the shoot system of an angiosperm plant, bearing flowers and, therefore, variously modified. Inflorescences are usually more or less clearly demarcated from the vegetative part of the plant. Biological meaning... ... Wikipedia
Scutellum: Scutellum element of the coat of arms Scutellum inflorescence Scutellum (entomology) List of meanings of a word or phrase with links to the corresponding ... Wikipedia
- (inflorescentia) a flower, as is known, represents a simple, vegetative bud modified for the purpose of reproduction, the axis (stem) of which has taken the form of a receptacle (and pedicel), and the leaves are transformed into bracts, perianth (sepals and ... ... Encyclopedia of Brockhaus and Efron
- (inflorescentia), a shoot (or system of shoots) of a plant that bears flowers. S. are characteristic of most flowering plants. They are divided depending on the degree of branching (1-2 orders of axes or 3 or more) into simple and complex. Depending on the … Biological encyclopedic Dictionary
- (corymbus), a simple botric inflorescence, which has a lower. the pedicels are longer than the upper ones and the flowers are located in the same plane. Emerged from a brush. Shch is characteristic of cultivated pears. (see 18 TABLE 18) fig. 2. .(