Electricity metering cabinet, pros and cons, placement methods

Each house, apartment or enterprise has an electric metering cabinet, which is necessary for taking readings of a consumed resource. This equipment is specialized, manufactured in accordance with the rules and regulations.

Product purpose

Before entering the consumer, electrical energy goes through several stages: generation and transportation via power transmission lines. Initially, electricity enters the shields, after which it is redistributed. At the same time, the installation of protection systems necessary for possible emergencies and incidents is carried out. Boards are used in manufacturing industries, installation is carried out in residential buildings or public buildings.

The main purpose of the cabinet is the reception and subsequent distribution of electrical energy. It also has the function of protecting the lines from possible overloads, short circuits. Structurally, the product contains the following elements:

a protective plate made of plastic or metal with switches fixed to it;
devices for calculating energy consumption;
input machine.

Installation of equipment is carried out:

inside buildings, structures;
outdoors.

The guards are designed for a standard voltage of 220 V or 380 V.

Electricity metering cabinets are made in a simple design, they are used for receiving and transmitting electricity for the operation of household appliances, sockets and lighting devices. The purpose of the shields is expanding, and there is a need to make more complex structures. Through one shield, electric current can be distributed to one apartment or the whole house.

Varieties

In total there are several classes of manufactured cabinets, the division is made by:

installation method - the design of the shields is wall or hanging. The most popular are boxes that fit into a niche, but only at certain sizes, planned for placement inside the walls;
the choice of material - a combination of metal with plastic - is an ideal option for the manufacture of cabinets, as it provides strength at the same time, and the material plays the role of a dielectric.

Recessed

Mounted

Cabinets are divided as follows:

at the place of installation: external or internal design;
by the method of placement: floor, built-in or mounted;
by type of electricity distribution: on fuses or circuit breakers;
by the method of connecting an energy meter: direct power or through transformer devices;
in terms of rated current: from 50 to 400 A;
according to the characteristics of the degree of protection of the shell: for placement indoors or outdoors (IP21 or IP54);
on placement in different climatic modifications (U3, UHL U31,);
according to operational characteristics, including the relation to external dynamic loads (M1, M2 and M3).

Apartment

Street

Types of cabinets for electric current metering:

SHU-1 is a cabinet equipped with a single counter, operating from a transformer or connected directly;
SHU-2 - the design of this equipment involves the installation of two meters connected via a transformer or directly;
ШУ-1 / Т - this device operates from a single meter, with the provided connection of a transformer and one test terminal box (hereinafter referred to as ICK);
ШУ -2 / Т - cabinet equipped with two transformer meters and a pair of IKK;
SCHUR - switchboard for metering energy, connected directly to the electricity distributor for several consumers.

The manufacture, installation or installation of electricity metering cabinets is carried out in accordance with the requirements of regulatory documents.

SHU-1

SHU-1-T

SHU-2

SCHUR

Equipment

The design of control cabinets takes into account both safety and ease of use. The box consists of a main body and a door.

The list of equipment elements:

fasteners for cabinets;
structural elements for input of electric current conductors, devices, clamps and connecting devices;
contact clamps for connecting external conductors of electric current, including special clamps for connecting zero working conductive elements and networks PE, N or PEN;
the door structure provides that it opens at an angle. It is convenient for maintenance, installation work, scheduled and other types of repairs;
various components are installed inside the cabinets: circuit breakers for differential electric current and circuit breakers provided without protection against high-frequency currents, modular circuit breakers with multifunctional releases C or B, as well as manual switching switches;
for direct-connected electricity meters, the manufacture takes into account performance with an accuracy class of at least 2, while the highest current indicator during operation is not less than the nominal value of the input apparatus;
the circuits installed inside the cabinets are made of copper conductors pre-insulated, while the cross-section is selected taking into account the connection diagram of the components of the structure and the rated electric current index;
insulation is provided for the wires, rated for at least 660 V of the supplied voltage.
zero protective conductors PE, N are provided by the manufacturer in various colors based on the requirements of state standards;
when designing cabinets, their execution is taken into account. Namely, functioning under moderate climatic conditions. The category of cabinets 1 indicates that the metering panels can be placed outdoors. The group of operating conditions in relation to the influence of mechanical stresses is external.

Installation of cabinets for metering consumed energy is carried out in accordance with the Rules, GOSTs and other standards, in accordance with a previously approved project. On the inside of the doors of the shields, the machine numbers must be clearly spelled out and in which particular room the power is supplied when the switch is turned on.

Where to post

Installed cabinets must be certified and have instructions for placement, repair and operation. Placement Requirements:

installation of shields should be carried out in a free place for maintenance, while the room must be dry, and the temperature regime is ensured not lower than 00 even in winter;
based on the standards, the placement of cabinets is allowed in unheated rooms of electrical substations, as well as outdoor installation panels. But for such cases, insulation is provided for the cold season: using insulation cabinets or methods of heating with an electric lamp. In this case, the heating temperature should not exceed more than 20 degrees;
cabinets designed for work in the manufacturing sector should not be installed in aggressive environments and at an outdoor temperature of more than 400;
height requirements from the terminal box to the floor should be in the range from 0.8 to 1.7 m. In exceptional cases, a height of less than 0.8 but not less than 0.4 m is allowed.
if cabinets for electricity metering are required to be placed in public buildings, structures, including stairwells and in corridors, then they must be closed, and the readings of the consumed electricity must be displayed on a separate dial;
the design of all cabinets must take into account the free access to the terminals and clamps, the installation or replacement of the meter from the front of the cabinet;
safety requirements when installing and replacing meters at a voltage of 380 V include switching off using switching devices at a distance not exceeding 10 m;
meters for energy metering from a transformer are carried out by remote located in an adjacent cabinet.

Each built-in cabinet must have an appropriate safety certificate, a locking device that is accessible to people who have been trained and certified according to the Electrical Safety Rules, including the installation of grounding devices is mandatory.

Selection tips

The main recommendations for choosing an electricity metering cabinet:

Before deciding on a choice, you should initially consider the installation location. Such a decision may be determined by an approved project;
the installation method is determined based on the capabilities, including the availability of free access, but this takes into account the requirements of the Rules and other standards;
the number of meters installed in the cabinet is also an important aspect;
value of the rated current parameter. In the technical characteristics of the cabinet, the current and voltage indicators for which it is designed are painted;
protection of the hull structure from environmental influences.

Additional recommendations for choosing an electricity metering cabinet:

Do not forget about your own safety when choosing a device, therefore, it is recommended to conduct an external examination for the presence of sharp edges and burrs;
the appearance must comply with the requirements of aesthetics, that is, non-paint, rusting, residual deformation of the metal, chips and cracks should not be;
it is not necessary to ignore the performance of locking devices, that is, you must first check the opening and closing of the lock;
if in doubt when choosing, you should ask for help from a specialist.

Installation of electrical panels should be carried out by a specialized organization having the right to engage in this type of activity. A properly selected and installed cabinet for metering electrical energy will contribute to maintenance safety and accurate readings.