Box for electric machines: types of boxes and their features + the nuances of selecting and filling the box
Equipping an apartment or house network, one has to deal with the choice of electrical equipment. And if it is not so difficult to choose a socket, then the purchase of a cable, an automatic machine or an electrical panel requires knowledge and preliminary calculations.
It’s not easy to get even an ordinary box for electric machines - the range of modern offers is so wide. We offer you to understand the variety of options and consider the criteria that are most important when choosing a box.
The content of the article:
- Appointment of boxes for machines
- Types of equipment in accordance with GOST
- Design features of electric boxes
- Box Specifications
- Tips from selection and assembly masters
- Conclusions and useful video on the topic
Appointment of boxes for machines
Plastic and metal boxes perform the same function as switchboards - organize the work of electrical equipment, serve for the installation of protective devices. In the literature, you can find other names: boxing, box, flap, panel.
The main “stuffing” for filling the box is made up of automatic machines, however, other protective devices can be located next to them - UZO and difavtomaty.
Large boxes contain indicators, circuit breakers, timers, differential relays. But to equip the network of a private house or one apartment, the installation of additional equipment is optional.
Boxes are mounted in apartments, on floor areas, as well as on the street, if it is necessary to connect to the electric main of a private house. They are diverse in design, assembly and function.
Types of equipment in accordance with GOST
According to legislatively adopted documents, both small boxes for 2 modules and large distribution cabinets-stations belong to distribution panels responsible for connecting electrical groups. The standards can be found in the editorial office. GOST 32395-2013.
Shields are divided into apartment boxes and floor - at the installation site. The next division is into distribution and accounting and distribution. The second is distinguished by the installation of a counter.
Thus, two broad categories can be distinguished:
- apartment - group and group accounting;
- floor - distribution, accounting and distribution, accounting and distribution and group.
By the installation method, all of these types are wall mounted or built into a specially prepared niche.
Junction boxes are protected against electric shock. According to this indicator, they can belong to I or II class.
Some floor products are equipped with special compartments for low-voltage equipment. Apartment boxes come with an apparatus at the input and without it, designed for a single-phase or three-phase circuit.
Design features of electric boxes
Electrical products differ not only in the size of the housing. They are manufactured according to the requirements set forth in GOST.
If the equipment is foreign-made, then it must also comply with Russian standards, otherwise the controlling organization simply will not allow connecting the apartment / house to the power supply highway.
If only installed inside circuit breakersLocking the door is optional. But safety devices and shutdown devices require mandatory locking of the box.
The main parts of the box for circuit breakers:
Mandatory are structural elements designed either for hanging the box on the wall surface, or for embedding it in a niche.
When choosing a box for an apartment and a house, it is necessary to take into account the number of automatic machines and other electrical equipment that is planned to be installed to protect the power grid.
The main guideline should serve as a diagram indicating devices in groups. In addition, you need to determine the type of box, the exact size, protection class and nominal values.
Electrical insulation and protection class
All electrical products, including those used in everyday life, must be protected from electric shock. This applies to boxing machines.
Turning off the automatic device or taking data from the meter, the owner of the apartment must be sure of his safety.
According to GOST 12.2.007.0-75There are five classes of protection, from 0 to III.
All electrical boxes belong to the I or II class of electrical insulation:
- I class - metal boxes with working insulation and 1-2 grounding elements;
- II class - plastic boxes with reinforced insulation without grounding elements.
The insulation class must be indicated in the technical documentation of the new product. You also need to take into account the installation location and, depending on it, choose a box with degree of protection from dust and humidity - from IP44 to IP65.
If the box with automatic machines is installed in the hallway, the lowest degree of protection is sufficient, but boxes for street use must have a mark not lower than IP54.
According to the rules of installation, boxes for electrical appliances can not be mounted in the kitchen, in the bathroom, combined bathroom, attached pool - that is, in any room where humidity is above normal
Case and part manufacturing material
There are 2 types of products according to the material of manufacture: plastic and metal.
Metal. Boxes belonging to class I are coated with a protective coating that is resistant to corrosion. They can be equipped with additional parts from other materials - grounding buses, contact clamps, connection devices.
Plastic. Most of the housing shields are made from a special heat-resistant polymer - ABS plastic. It is a shockproof material that withstands heating up to an average of + 650 ° C. It is not prone to spontaneous combustion, and in the event of an emergency it can only melt, but not burn.
The design of the plastic box does not deform over time, as it takes shape during the heat treatment. The surface is not exposed to ultraviolet radiation, that is, it can safely be mounted on a post or the outer wall of a building.
The shells of the polymer boxes are very lightweight and easy to install. Modern drawers have extruded inputs for connecting wires and pivot doors.
If the box is planned to be installed on a wooden wall, then the requirements are increased. Suppose that the details of class II boxes, built-in or external, must be resistant to heating the wire to + 850 ° C.
Number of rows and modules
Another important characteristic is the dimensions of the box. Inside the box are horizontally directed strips - DIN rails.
Each of them is designed for a certain number of places (modules). The width of one place is approximately 1.75 cm. For example, one machine occupies one place, and an electric meter - from 5 to 8.
Boxing for a living room has a compact size and is designed for an average of 12-36 places, depending on the number of electrical circuits.
But manufacturers usually expand their assortment by increasing the size range, so in their collections you can also find the smallest boxes with 2 switches, and large panels that hold up to 180 modules.
Small boxes are convenient when the protective devices are located in several places. For example, if the RCD and the meter are installed on the street, and the group shield is inside the house. Option for urban installation: switch + counter on the site, distribution box - in the hallway.
All nominal values are indicated in the technical documentation, they must be taken into account when choosing apartment or floor boxes, as there are differences. For example, in urban high-rise buildings, the nominal input voltage for apartment boxes is 230 V, while for floor boxes there can be both 230 V and 400 V.
According to the rated currents of 1-phase and 3-phase input devices, the boxes do not have differences, for all types, values from 25 A to 63 A are suitable. The rated currents of individual machines and differential devices depend on energy consumption and can vary from 6 A to 40 A.
It should be remembered that it is strictly forbidden to install the apartment box as a floor switchboard.
Modifications for installation on the site should be designed for a minimum of 2, a maximum of 4 apartments. If more connections are required, an additional box must be installed.
Tips from selection and assembly masters
Given these and other characteristics, choosing a suitable box even for arranging a network in a small apartment is not such a simple matter.
It is better to consult a qualified electrician and, at a minimum, order a professional wiring project. Based on the scheme, it is possible to carry out the assembly of the electric box.
In the design of the future shield, every detail is important. As an example - apartment boxing ABB.
This is the box that is most suitable for mounting machines without buying additional parts.It costs more than a metal box without tires and frames, but much more convenient in installation and use.
On the base of the case there are even extruded hatches for wiring and small grooves for more convenient distribution of conductors inside the box.
For installation in the wall, dowels are used, and the gaps between the niche and the box are covered with plaster or gypsum. If the frame with slats is removable, then all the installation work of the case can be performed together with construction measures for wall decoration, and the assembly of the box later.
We recommend that you pay attention to the products of brands that have long established themselves in the Russian market: ABB, Legrand, Vico, IEK, Makel, Schneider electric.
Conclusions and useful video on the topic
Box assembly - all in order:
How to save on purchase and assembly:
The process of mounting the shield and cable connections:
The choice and installation of distribution equipment is best entrusted to a qualified specialist - an electrician from the management company or an electrician with a license hired from the outside for the installation of electrical wiring.
But it is better to own information about the boxes and the homeowner - to take urgent measures in an emergency or a small independent repair.
Have something to supplement, or have questions about choosing a box for an electric machine? You can leave comments on the publication, participate in discussions and share your own experience in the purchase, installation and filling of the box. The contact form is located in the lower block.