Outdoor box for an electric meter: requirements and features of choosing and installing an electrical panel
Owners of private households sooner or later have to take their utility metering devices outside.Service organizations have a number of requirements for this event. One of them is the corresponding clause of the PUE, according to which the shield is installed on the facades of houses, supports, pillars, fences, etc.
We will tell you how to place and secure an outdoor box for an electric meter in accordance with building regulations. The article we have proposed describes in detail the selection criteria and rules for installing a box for a flow meter and other equipment. Useful recommendations for assembling the shield and carrying out installation are given.
The content of the article:
Purpose of street boxes
The box must perform three functions. The first is to ensure the safety of people during maintenance and operation of the electrical network. The box must be grounded.
The second is to create optimal conditions for the devices located inside. The structure must be well protected from atmospheric influences: moisture, sunlight, wind.
The third is to provide access to the metering device to representatives of the service organization. This condition is specified in contracts with consumers, although the PUE does not contain a direct requirement to install meters on the street.
Types of boxes by type of design
Foreign and domestic manufacturers offer boxes of different sizes and capacity.The option is selected depending on the parameters of the equipment that is planned to be placed in the box.
There are also certain markings that indicate the type and purpose of the box. Example:
- control room - ordinary and simplest;
- ShchVR - a box built into the wall;
- ShchRN — distribution and hanging box.
If it is just a metering panel, it usually contains only a meter, an input machine, grounding and neutral buses. Residual current devices, and circuit breakers installed in the “home” box. But you can combine all this in one box.
The design of the shield can be:
- floor;
- built-in;
- invoice or mounted;
- hidden or open;
- whole or collapsible.
What kind of equipment, in what quantity and with what parameters should be installed in the box - all these points are specified in the project power supply for a private home. If there is no such document, you need advice from relevant specialists.
Basic criteria for choosing a box
The main task of the consumer is to find a durable, practical box that will withstand long-term service in outdoor conditions. The box should be convenient for installation and operation.
What is important about the design itself? The presence of holes of the appropriate diameter for the wires that come from the support and lead out to the building. It is desirable that these elements have rubber seals and plastic couplings.
A convenient detail is the window.It eliminates the need to open the shield to take readings and reduces the frequency of contact of the internal contents with air and moisture. Pay attention to the sealing lugs.
The IP20 index means that the box is protected from dust particles larger than 12.5 mm, but is vulnerable to moisture. Degree of protection IP65 guarantees complete isolation from these negative factors. The higher the number, the more expensive the design. The optimal option is with a score of 54.
When choosing an electrical panel, you also need to look at the thickness of its walls, operating temperature range, number of doors, and type of lock. The box can be locked with one individual key or equipped with several identical ones.
Box installation requirements
The metering device and additional equipment may only be installed in a sufficiently rigid structure. It must be well insulated from moisture and other negative atmospheric phenomena.
Meters with significant temperature changes can give errors in readings, so it is recommended to insulate the box with special caps or heating elements. This will also extend the life of the devices.
Main points PUE-7:
- The distance between the floor and the box with the meter terminals should be in the range of 0.8-1.7 m. The deviation of the first indicator is allowed up to 0.4 m.
- If the location is accessible to unauthorized persons, the box must be equipped with a secure lock and viewing window.
- The design and dimensions of the cabinet must provide easy access to all elements of the installation and the ability to replace devices, if necessary.
- During installation, the ends of the wires from 12 cm must be left near the meter. A piece of the neutral wire at a final length of 10 cm must have a distinctive color.
- Grounding with copper protective conductors is mandatory.
- Electrical wiring must not have any solders.
- Verification periods: for three-phase meters - 1 year, for single-phase meters - 2 years.
In addition to the requirements for the meters and boxes themselves, the rules also apply to cables, wires, and fastenings. For a multi-core cable, it is mandatory to use an NShVI (tip). When attaching cable ends to equipment, sealed glands (glands) are also needed.
DIY wardrobe
If you have experience and desire, you can arrange a cabinet for an electric meter yourself. You will need to buy the structure itself, arm yourself with the necessary tools and carry out electrical panel assembly in accordance with the specifics of the home electrical network.
If you come across a cabinet of the required dimensions, but it lacks a window, lugs for seals or some holes, it is permissible to add these elements. But the work must be carried out in accordance with safety regulations and the requirements of regulatory organizations.
All necessary equipment is mounted on DIN rails. Many models of metering devices come with parts that may be useful during installation (stickers, caps, fasteners). The main task is to assemble the devices and connect them correctly with each other.
Models of external meters
If you are buying a new meter and not removing the existing one from the premises, you need a device suitable for use in outdoor conditions.
Please note the following points:
- Induction models are much more sensitive to temperature changes than electronic ones.
- DIN rail is preferable as a mounting method.
- Go to the website of the electricity sales organization and see which models are allowed for installation in Russia.
- For a multi-tariff payment system, choose a device that can take into account more than three tariffs.
Brand recognition and the presence of service centers also matter. A trusted manufacturer means quality, maintainability, and loyalty of inspection organizations.
Among the commercially available domestic brands, we can consider the following: INCOTEX, Taipit, Energomera, EKF. Particularly popular is the model “Mercury” 230 AM-03. It has a single tariff and is capable of giving accurate readings at temperatures ranging from -40 to +55 degrees.
Of the foreign manufacturers that have proven themselves well: Swedish-Swiss ABB, French Schneider Electric, Turkish Legrand. But European brands often have operating temperature ranges that do not correspond to Russian realities.
It is advisable to consult with specialists from the service organization in your region. Usually they have a list of devices that have already shown their best performance during operation.
Automatic and heater
An automatic switch is installed in the box before the meter.Its parameters must be calculated from the total power of all consumers - electrical appliances installed or planned in the house and on the street/garage and other domestic buildings.
If, for example, the total power is 25 kW, then a 63 A automatic machine is optimally suitable for this value. In addition to the input one, you need an outgoing line automatic machine, protective for the heater and modem (if any). Using the latter, the readings are automatically transmitted to the processing center. But such a scheme cannot do without a heater.
Heaters for electrical panels are made of aluminum, which is coated with non-flammable thermoplastics.
The main functions of the element are to prevent the appearance of condensation, which prevents corrosive changes in current-carrying busbars and contacts and protects devices from high humidity.
Transfer input device and SPD
If the electrical installation includes an autonomous power source, a backup device must be installed after the meter. This device is needed to manually switch consumers from the external network to the generator and back.
To protect the installation from lightning strikes, high-voltage surges and fires from these impacts, an SPD (surge protection device) is added to the panel. It is placed after the input circuit breaker and through a separate fuse. An SPD is required if entry into the building is carried out via an airway.
Additionally, the shield can be installed fire protection RCD, a cross-module for distributing electricity to different groups of consumers. Sometimes a differential machine is also added to the box.
The socket is one of the optional elements. But if construction is just underway on your site or you need a street connection for some equipment, you can’t do without it. And don’t forget about the zero rail, it combines all the zero cables and is used for connecting cores.
How is installation carried out?
All equipment must be connected by an electrician, provided he has the necessary documents for such work. The owner of the power line has such specialists. Inviting someone else or doing everything yourself is not practical.
Unqualified craftsmen may not compare the technical characteristics of the input equipment with the actual loads on the network, “forget” about electric shock protection devices, or even make gross mistakes in the sequence of their connection. Therefore, it is highly desirable to know how installation is carried out.
First, an input device is equipped - this is the cabinet itself, where there are mechanisms for protecting and connecting incoming cables to outgoing ones. It’s good if the pipe with the cable goes directly into the box itself. Let's consider the connection process using the example of a three-phase network.
There are many switches on sale; one three-pole circuit breaker will do, which can be moved outside the input device. One of such designs is YaBPVU-100.This is an iron box with break contacts and 100 A fuse links.
The most important element of the input device is the grounding bus, to which repeated grounding with a neutral incoming conductor is connected. It splits the PEN conductor into a ground wire and an outgoing neutral. Then the cable from the box goes to the house, where its own panel is installed.
Zero splitting can also occur in the input device itself. In this case, the panel will be called an input distribution panel.
If you intend to disconnect street wiring, you can make a special outlet from the main panel. Thus, devices designed for three-phase power supply will have separate circuit breakers and RCDs.
The equipment is connected via power plug connectors or busbar boxes. Their degree of protection must be greater than or equal to IP45.
How to assemble and install a panel for a meter in an apartment is written in detail in next article, which we recommend that owners of urban housing familiarize themselves with.
Conclusions and useful video on the topic
Video #1. Assembling all box elements before installation:
Video #2. Assembly and installation of a three-phase meter instead of the old single-phase one, plus an estimate for such work:
Video #3. Analysis of the process of connecting electricity from a support (pole):
To install a box for an electric meter on the street, you need to select the box itself and its internal equipment so that the structure and devices can withstand outdoor conditions. You can assemble the panel yourself, but it is better to entrust all connections from the support and to the house to a specialist from a service organization.
Would you like to tell us about how you assembled and installed an electrical panel on the street in front of your own dacha or country house? Do you have technological subtleties that are worth sharing with site visitors? Please write comments in the block below, ask questions and post photos on the topic of the article.
At the very beginning of the text, a statement is made that the meter must be taken outside the house. What purpose? Is this someone's requirement? I often visit the private sector, but I have not observed anything like this. But let’s say we still take the device outside to provide free access to it for inspectors. But by doing this we also ensure free access for various marginalized people?
Formally, the requirement to install an electric meter on the street is illegal, and if you really want to “fight” with energy workers, you have the right to refuse, but be prepared for the courts.
What’s stopping you from placing an electric meter in a box inside your property, behind a fence, where the marginalized people you fear won’t get through?
They correctly wrote to you that you can sue and force power engineers to abandon their demands. But how much nerves and time will it take?
It won't take any of the nerves away. I’ll also answer Anton right away. By the way, there will be no trial either. There can only be recommendations, not requirements for removing the electric meter.
Clause 1.5.27 of the PUE states that:
«The metering device should be installed in a place that is easily accessible for maintenance and with a temperature in winter not lower than 0 degrees. C.
It is allowed to place meters in unheated rooms and corridors of switchgears of power plants and substations, as well as in outdoor cabinets. In this case, provision must be made for their stationary insulation for the winter through insulating cabinets, hoods with heated air inside them with an electric lamp or heating element to ensure a positive temperature inside the hood, but not higher than +20 degrees«.
Clause 1.5.29 PUE: “The permissible installation height of the meter is in the range from 0.4 to 1.7 m from the floor". That is, this height is easily accessible to thieves and vandals.
Due to these standards, it is difficult for the owner to ensure the safety of the meter. Although, Art. 210 of the Civil Code of the Russian Federation states that: “The owner is responsible for the safety of his property, unless otherwise provided by the contract«.
In connection with these points, the law on the obligation to remove the meter does not exist, and the resource supplying organization simply does not have the right to demand this. If someone obliges you, simply request a normative act established at the legislative level. An interesting practice is in SNT, where they allegedly try to oblige someone at a general meeting that all owners take out the meters. And often, people fall for it, although in this case, you have every right to refuse to remove the meter.
Good afternoon, Anton, other participants in the discussion.
Energy engineers pursue the only goal - availability of the meter to inspectors at any time of the day. Attempts to install street metering boxes at an accessible height recommended by the PUE were faced with obvious consequences in Russia - the devices were broken and stolen.
Today, power engineers have begun installing special meters near the supports of 0.4 kV overhead lines. To read the readings, owners are given remote controls that “see the numbers” even from the window of the house - they recorded the reading on the billing day and handed it over to the energy supply organization. Examples of innovation include Orenburg, Tver, and many other cities. By the way, installation is free in Orenburg.
I watched as the controller of Orenburg Energosbyt T+ took readings using a laptop - Wi-Fi was working. I have attached a photo of such a counter.
And where is the point from PUE 7 section 1., chapter 1.5, point 1.5.27 - heating the box? Probably major sclerosis. Where does the condensation that forms due to temperature changes, which leads to damage to electronics, go? And who is responsible for the integrity and serviceability of MY equipment installed on the STREET? Uncle? Or post security?
Hello. Not an uncle or a security guard, if you did not enter into such an agreement with them, but according to the law, it is you who are responsible for your IPU. Of course, we fully understood your sarcasm, now about your indignation...
The article was written not with a recommendatory nature about installing a metering device on the street, but for those who install such devices voluntarily and of their own free will. This usually happens to those who are away from home for a long time, work a lot and the controller cannot find anyone at home, or simply does not tolerate strangers with mandatory checks on their territory. To avoid fines, this option is often very convenient.
Hello! I have a question - we have an electric meter in our house that we use.The energy supply company installed its meters on poles on the street. Our actions? They carry remote controls and hand them out to residents. Is all this legal?
Hello. Please read the Federal Law of December 27, 2018 N 522-FZ “On amendments to certain legislative acts of the Russian Federation in connection with the development of electrical energy (power) metering systems in the Russian Federation.”