No one argues that electricity is a good thing, but you have to pay for it.
Installed in many homes, they are designed to help stabilize payments and, if possible, minimize them.
Types of devices
The operating principle of any meter is to measure active energy and calculate the energy spent.
There are several options for counters.
They share:
- according to the connection principle - to direct and transformer connected devices;
- according to measured values - single-phase and three-phase;
- by design - mechanical, electronic and hybrid;
- by the number of tariffs - single-tariff and multi-tariff.
Mainly used for electricity metering electronic devices, which have a number of advantages: they are more accurate and allow you to use several tariffs, to which they are transferred independently, without the participation of the owners.
It is worth noting: There are also hybrid meters that have a digital interface and a mechanical computing device, but, judging by the reviews, they are used extremely rarely.
How does it work
Electrical metering is based on direct measurement of voltage and current: all information about electricity consumption is supplied to the indicator and stored in the device’s memory.
At the same time, the device has a number of advantages:
- It allows information to be read more accurately, which prevents electricity theft.
- It is smaller in size compared to mechanical ones.
- Can automatically switch between different tariffs without requiring human presence, which saves money.
- Electronic models are checked every 4-16 years. This is necessary to verify the correctness of the accruals. The verification is carried out by the Sphere of State Regulation of Ensuring the Uniformity of Measurements.
Note: The first check is carried out at the factory - its date is indicated in the device passport.
Along with the advantages, there are usually some disadvantages. These include higher cost and unreliability: despite the assurances of manufacturers, electronic models have to be replaced more often than mechanical ones. The latter can work for several decades, since there is practically nothing to break in them.
Schematic diagram electronic counter. (Click to enlarge) Electricity is calculated by converting the current and voltage signals “entering” the device into a pulse, which it counts.
The number of the latter varies in accordance with the incoming energy. That is, the more electricity is consumed, the more impulse the device will receive and count.
Together with the counting device, the electronic meter has a display that reflects changes in current consumption, maximum and minimum values, the current tariff and other data necessary for the owners.
Single-phase and three-phase models
The main principle of dividing electronic meters is the measured quantities themselves and technical characteristics.
They are:
- Single-phase: they are used in apartments, separate houses, small offices and other sites powered by a network of 3-7 kW with a voltage of 220 V. Such devices are designed for currents of 13-32 A (1 kW = 4.5 A, respectively, 3 kW is 13.5 A). When choosing a device, it is necessary to take into account that it must indicate the rated and maximum current values, usually this corresponds to 5-40 A.
- Three-phase: they are usually used in industrial and domestic buildings with a high current flow, as well as in private cottages, where input occurs only through a three-phase system. The most in a simple way To choose a suitable device, you will need to contact the appropriate services: they will be able to help in the choice by naming the main characteristics or models.
It is worth noting that a three-phase meter must have an internal tarifficator. It generates a load schedule and monitors the transition of tariffs, notes overvoltage and lack of current, its operation, a decrease or increase in voltage. This helps in taking meter readings.
Take note: electronic three-phase meters usually have an event log in which all changes in the “operation” of the current are noted for timely troubleshooting.
When choosing an electronic electricity meter, it is better to choose models with a larger warranty period and the specified service life, and also make sure that there is a company workshop in the city. This will help reduce costs in case of breakdown or installation of a new one.
The electronic version of the meter is currently used in great demand in apartments and houses. Thanks to its advanced capabilities, it prevents energy theft and can help save money for the homeowner.
When choosing a model, do not skimp: cheap option made from fragile materials will last much less than a more expensive one.
Watch the video, which uses the example of a specific brand to discuss the features of electronic electricity meters:
Electric meters are usually installed in all apartments and private houses. They measure the energy consumed alternating current, because in any living space there are many modern household appliances. Availability of a counter electrical energy – mandatory requirement all local energy sales companies, unless, of course, you are on a desert island and do not use electricity yourself obtained from solar or wind energy.
Meters are different and differ in the type of design and connection. In this article we will find out how to choose a single-phase electricity meter and connect this device in your home.
What does a single-phase electricity meter mean?
So, single-phase meters are designed to measure alternating current in a network with a voltage of 220 V and a frequency of 50 Hz (one phase and zero). These devices are installed in all city apartments, small shops, country houses, garages, etc. They are quite convenient to use and easy to take readings from.
Unlike single-phase ones, they are designed to work with a 380 V / 50 Hz network (three phases and zero). Typically these are homes, offices, administrative and industrial buildings with high electricity consumption. Typically, three-phase meter models are also used for single-phase metering.
How to choose a single-phase electricity meter?
When purchasing, pay attention to the labeling: devices that transmit single phase current, must be marked “CO”, in contrast to three-phase ones marked “ST”. As we have already found out, both types of meters are suitable for a single-phase network, but do not rush to buy a “more powerful” three-phase device for your home unless there is a special need. Indeed, due to the higher voltage in the case short circuit the consequences will be much more dangerous. At the same time, installing a three-phase meter in an ordinary residential building makes sense if you are afraid of overloading the electrical network with an abundance of powerful appliances, such as heating boilers, etc. The main thing is to treat the issue of fire safety with full responsibility.
However, ordinary single-phase meters are also different. First of all, they are divided into single-tariff and multi-tariff. This means dividing energy consumption into periods of time, which are charged differently. And since tariffs and conditions in regions and cities are different, the feasibility of installing a single-phase multi-tariff electricity meter instead of a single-tariff one should be calculated separately for each specific case.
In addition, there are induction (conventional) electricity meters and electronic models, some of them are equipped with a liquid crystal screen. The latter are considered more convenient and accurate.
How to connect a single-phase electricity meter?
A single-phase electricity meter is easy to use, but should only be installed by a professional electrician or someone with the appropriate skills and qualifications. For this you need 
First of all, carefully study the documentation of the meter and its connection diagram, and also first de-energize the line. As a rule, any single-phase model has 4 contacts on the terminal block: this is the phase input to the apartment and its output, as well as the zero input from the external network and its output into the apartment. Actually, in this sequence you need to connect the meter wires to the contacts.
After installation, the meter must be sealed by employees of the local energy sales organization. And if the meter is replaced, you should contact the utility company in advance so that they remove the seal from the old one and immediately install it on the new device.
With this material we begin a series of articles under the general title “I want to buy.” Often people come to a store with the goal of buying some product, but they do not know what exactly they need. Therefore, they tell the seller: “I want to buy, but I don’t know what to choose.” These articles will be, in a way, a detailed response from the seller to such a buyer.
So, let's begin. In the first article we will answer the buyer’s question: “I want to buy an electric meter, but I don’t know which one to choose. Which one do I need?” After reading this article, you will know which electric meter you should buy: , , , , and . And when you come to the store, you can proudly say, for example, like this: “I need a single-tariff, single-phase electric meter, for a current of up to 50 amperes, an accuracy class of no worse than 2.0, with DIN-rail mounting, no more than two years have passed since the verification date.” years!"
If you have not yet decided which panel or box you will install, then buy a meter with a DIN rail mount. This type of electric meter is more universal: you can always purchase either a rail or an adapter strip for it and install it on a flat surface (for example, the mounting plate of a PCB board) or on three screws.
What current should I buy an electric meter for?
As a rule, single-phase electronic electricity meters are produced for currents from 5A to 50-60A. Three-phase electronic electricity meters are produced directly at maximum current up to 50A and up to 100A and transformer connection- for currents up to 10 amperes. In residential construction and apartment renovation, transformer connection meters are practically not used, since loads rarely exceed 100 amperes.
But there are also exceptions. For example, there is a single-phase electronic device electricity metering Neva 103, which is designed for a maximum current of 80A. But as a rule, in apartments and houses connected to a single-phase circuit, the consumption currents are much lower.
If you have new house, then there should be a project for it, which specifies at what current the electric meter should be installed, how much power is allocated to the house and which input circuit breaker should be selected. If you are making repairs in an apartment and changing the wiring there, you can determine the required current by the cross-section of the wire that fits the meter. That is, if an aluminum cable with a cross-section of 6 sq. mm, which can withstand up to 39A, is suitable for the apartment, then there is no point in installing Neva 103 at 5-80A.
What accuracy class should I buy an electric meter?
The accuracy class is indicated on front panel in a circle and indicates how accurately it will count the electricity consumed. Sometimes you can hear the phrase: “You need to buy a less accurate meter and then you will pay less for electricity.” But it is worth remembering that the phrase “less accurate” does not mean that it will count in your favor!
According to Chapter 1.5 of the Rules for the Construction of Electrical Installations (PUE), for the population, the accuracy of active energy meters must be no worse than class 2.0. That is, you can install metering devices of classes 2.0; 1.0; 0.7 and 0.5. And metering devices with an accuracy class of 2.5 and lower are no longer produced, since they can no longer be installed.
When should the meter be released?
In fact, it is not the release date that is more important, but the verification date. Before going on sale, all metering devices must go through state verification (testing for operability and measurement accuracy) at the manufacturer. Based on the results of a successful verification, if the meter has passed it, a state verifier’s seal is placed on the meter body, and a seal is placed in the passport. The date is also indicated in the passport, and the quarter and year of state verification are placed on the seal.
According to the PUE (clause 1.5.13) “every installed settlement meter must have seals with the stamp of the state verifier on the screws securing the meter casing, and on the clamping cover - the seal of the energy supply organization. Newly installed three-phase meters must have state verification seals that are no more than 12 months old, and single-phase meters must have state verification seals that are no more than 2 years old.”
That is, your single-phase meter must be installed and sealed by the energy supply organization no later than two years after verification, and three-phase - no later than 1 year.
Periodic checking of the performance and measurement accuracy of the meters is also required. Therefore, for each type of metering device there is also a verification interval, which for electronic meters is usually 10-16 years from the date of production.
Something else?
There are active and active-reactive energy meters. Reactive electricity metering is used mainly in enterprises with meters connected through current transformers.
There are also meters for working in automated systems for monitoring and accounting for electricity (ASKUE). But we did not consider this issue here, since the requirements for installing such meters are usually specified in the requirements for installing metering devices or in the connection project. These documents usually indicate a specific model, which depends on the type of ASKUE used in the region. But you should still remember that you can install any electricity meter yourself, which is certified and included in the State Register of Measuring Instruments.
All of the above applies to a greater extent to electronic electricity meters. We did not consider induction meters separately, since every year they are produced and used less and less: they are more expensive, less accurate, larger in size, and have a shorter calibration interval (usually 8 years).
Dear guests of the site “Notes of an Electrician”. Firstly, today I want to congratulate everyone on Orthodox holiday Epiphany.
Secondly, I have prepared for you an article on choosing an electric meter for metering electricity.
Electric energy meter is an electrical measuring device that is necessary to account for electrical energy consumed in everyday life or in industrial enterprises.
This device is very necessary for monitoring electricity consumption over a certain period of time and makes it possible to save on this.
Currently, the market is overflowing with electricity meters different types and with various technical properties and characteristics. Therefore, the purpose of this article is to help you do right choice electricity meter.
According to the principle of operation and type of device:
- induction (for example: SO-I446, NE-1-44, SAZU-IT, )
- electronic (for example: CE 102, )
Induction meters electrical energy is electromechanical devices, which work on the principle of rotating a metal disk, the number of revolutions of which is used. Induction meters have the only advantage over electronic ones: price and calibration interval.
Electronic electricity meters are electronic devices whose operation is based on semiconductor technology and microcircuits. They do not have rotating mechanical parts, and the conversion of input signals comes directly from voltage and current sensors. Electronic meters are produced with a higher accuracy class.
By number of phases:
- single-phase
- three-phase
Single-phase electricity meters are used for single-phase networks, respectively, three-phase - . IN Lately three-phase began to be produced electronic electricity meters, which can be connected to a single-phase network.
Conversely, 3 single-phase electricity meters (per phase) can be connected to a three-phase network. Thus, we will keep electricity records for all phases separately. current transformers with secondary current 5 (A).
By voltage class:
- 220/380 (V)
- 100 (V)
If your facility receives power via high voltage line 6 (kV) or 10 (kV) and you need electricity metering on the high side, then in this case it is necessary to use voltage measuring transformers with secondary voltage is 100 (V). Therefore, you must install an electric meter with a voltage class of 100 (V). In this case, current transformers are also used.
By number of tariffs:
- single tariff
- two-tariff
- multi-tariff
If you have a two-tariff meter, it becomes possible to pay for electricity consumption at two tariffs: day and night. The difference between these tariffs lies in the cost of electricity, which differs by almost 2 times. Check out.
The day rate operates from 7:00 to 23:00, after 23:00 the meter automatically switches to the night rate, which continues to operate from 23:00 to 7:00.
Therefore, many of our citizens, if they have two-tariff meters They also actively begin to use other energy-intensive devices at night.
Choosing an electric meter for an apartment or house is not as simple a task as it might seem at first glance. Suppose you decide to replace old electric meter for an apartment, house or garage, but so that when you come to an electrical goods store, you don’t get confused at the first question from the seller, what kind of electric meter do you need for your apartment, so that the seller doesn’t sell you an expensive electric meter with many functions that you absolutely don’t need, or vice versa, will sell you old junk that is lying around. I wrote this article so that you can easily choose an electric meter for an apartment or a private house, what basic parameters of the electric meter to pay attention to in order to buy exactly the electric meter for the apartment or house that you need. The article discusses the most common meters in our country - Mercury and Energomera.
Single-phase or three-phase electric meter
To choose the right electric meter for an apartment or house, you need to decide how many phases your electrical network has. Everything here is quite simple, if a cable with two conductors (phase and zero) is suitable for your input circuit breaker in an apartment or house, it means you have a single-phase electrical network and you need an electric meter for your apartment single-phase. This type of electric meter for an apartment is designed for a voltage of 220 V, which will be indicated on the electric meter panel.
If a cable of four cores comes to the input machine of an apartment or house, then you have three-phase network (three phases and zero), for which it is set three-phase electricity meter Three-phase meters are designed for phase (between one phase and another) voltage of 380 V, and will also be indicated on the meter panel. Can three phase electricity meter for an apartment, turn on 220 V, it will be correct to count the electricity meter, but here it’s up to your discretion network organization Whether the inspector will accept (seal) such an electric meter or not depends on the inspector himself, and internal rules Your network company, I repeat, will calculate the electricity meter for the apartment correctly. This example is more likely for those cases when the network is three-phase, the meter is three-phase, but only one phase is involved, in this case the metering will be correct.
Methods for installing (mounting) an electric meter in a panel
Next, we decide how the electric meter for an apartment or house will be installed in the electrical panel, first of all - it depends on the, if the design of the electrical panel allows, then we choose an electric meter for an apartment or house, which is installed on a DIN rail:
If you have an electrical panel of a different design, the electric meter for an apartment or private house can be installed on a mounting panel in the panel:
Usually, electric meterfor an apartment or private housein the first option, it is installed indoors, and in the second option, in input distribution devices (IDUs), metering panels, etc. on the street, but it also happens in different ways, depending on the situation.
Date of issue (verification) of the electric meter
In my opinion, and even more so from the inspectors of the network company, this the most important moment, because if there is a dishonest seller in the store or simply unknowingly “steals” you single-phase electricity meter for apartment, issued more than 2 years ago, then according to the rules of electricity metering, the inspector will not accept such an electric meter from you and will force you to check the electric meter for your apartment, house, or, which will be much faster, buy a new one. For three-phase electricity meters- the period is even shorter, and amounts to no more than 1 year. The issue date can be seen on the electric meter panel and in the passport (form) for the electric meter in the apartment.
Single phase electricity meter
Three-phase electricity meter Mercury 230 ART
Let me note one more point: when you install a previously used electric meter for an apartment somewhere (it was in an old house, garage, gifted by a friend, etc.), then for the electric meter for the apartment you must have a certificate of verification not older than 1 year for three-phase electricity meters and 2 years for single-phase ones, i.e. you can use an old electric meter for an apartment if it passes state verification before installation.
Please remember this first of all, so as not to disrupt your plans for connecting electricity; without an electric meter, no one will supply electricity to your house.
Maximum and rated (base) current of the electric meter
We have already decided on a single-phase or three-phase electric meter for an apartment or at home, we need it, then we need choose an electricity meter by maximum current , i.e. according to our maximum load (the sum of the powers of all electrical appliances, this will, of course, help us first of all, where on the single-line diagram on the input circuit breaker its maximum current will be indicated. If you are simply replacing an old electric meter for an apartment or house with a new one, then just look at the maximum current on the machine itself in the electrical panel, or on the panel of the old electric meter, and select an electric meter for the apartment or house with a current higher than that of the machine, i.e. if your input circuit breaker is designed for 32 A, then the electric meter must be selected at least 40 A. As an example, the photo shows an electric meter for an apartment, through which more than 60 A should not “flow”.
The first current value of 5A and 10A is for an apartment. The second value of 60A and 100A is maximum current. Within these limits, the electricity meter for an apartment or house will count correctly, with the stated error (accuracy class). If the operating current is greater than the maximum, then most likely your electric meter for the apartment will burn out, but if it is less than 5A and 10A, then the electric meter will have an error greater than stated, perhaps in your favor, or perhaps vice versa, it will overestimate the readings.
Electric meter accuracy class
It is necessary to decide which accuracy class (maximum error, expressed as a percentage) will be our electricity meter for an apartment, house; the lower the accuracy class of the electricity meter, the more accurate the electricity meter will be. The error can be either in your favor (under-metering), or vice versa - the electric meter for an apartment can overestimate the readings (over-metering).
Everything is simple here, if you buy an electric meter for an apartment, house, cottage or garage, then according to the requirements for electricity metering, the accuracy class of the electric meter should be no more than 2(for the population, and categories equated to them, for example, such as GSK), if you purchase an electric meter for commercial purposes (enterprise, store, car service, etc.), then the requirements in terms of legislation are stricter, an electric meter is needed with an accuracy class no more than 1. They produce electricity meters with accuracy classes 0.2, 0.5, 1 and 2, although they can still be found (old housing stock) with an accuracy class of 2.5, but according to the law, it is high time to replace them with more high class accuracy. The higher the accuracy class of an electric meter for an apartment or house, the higher its price. The accuracy class of the electric meter, according to GOST, is indicated on the panel of the electric meter in a circle.
Multi-tariff electricity meter
The main parameter from the point of view of savings is the number of tariffs included in the electricity meter for an apartment; there are single-tariff, double-tariff or multi-tariff electricity meters. Let's take a closer look at two tariffs m, where the day rate is from 7:00 to 23:00 and the night rate is from 23:00 to 7:00.
As an example, pLet's look at electricity tariffs in Moscow in 2014.
The table shows that the night tariff T-2 is 75% lower than the day T-1 tariff, so if, for example, of your monthly 200 kWh, the night tariff T-2 accounts for half of the electricity consumed, then the price for electricity will be equal to:
C=Wday*T-1 + Wnight*T-2 = 100*4.53 + 100*1.16 = 569 rubles
With a single-rate tariff, when the price for electricity is the same at all hours of the day:
C=W*T = 200 * 4.50 = 900 rubles
The difference was 331 rubles, and in a year it will already be 4,000 rubles. Your multi-tariff electricity meter for an apartment or house will pay for itself in almost 1 month, and in the future you will actually save on electricity bills. And if you have your own house with a consumption of not 200 kWh per month, but 2,000 kWh ( electric heating, electric heated floors, turn on the washing machine only at night), then the savings with a multi-tariff electric meter will be much more significant.
But......not everything is the same for everyone when it comes to paying for electricity with two-tariff electricity meters, let’s take another region - the Kursk region:
In the Kursk region, the price for electricity, if the electric meter also “winds up” 200 kWh, will be at the “day-night” tariff equal to:
C = 100*3.22 + 100*2.41 = 563 rubles
And with a single-rate tariff:
C = 200 * 3.05 = 610 rubles
The difference with a two-tariff electric meter for an apartment or house is no longer so significant, and this is taking into account electricity consumption day and night 50/50. And if in a private house this is quite realistic to achieve - by increasing the power of the electric heating of the house at night or heated floors, and decreasing during the day, then in the apartment consumption during the day in most cases will be 80 percent, and this will lead to the fact that at the “day-night” tariff you will pay more than at the single-rate rate. But if the difference in the price of an electric meter of 600-800 rubles is not significant for you, then purchase a multi-tariff electric meter for an apartment or house. In case of constant overpayment at the day-night tariff, you can always switch to a single tariff by writing the appropriate paper to the energy supply, if you pay for electricity directly to them, or to your management company.
In my opinion, the transition to a multi-tariff regime, first of all, depends on a person’s lifestyle; if a person constantly wakes up at 7 am and goes to bed until 11 pm, then the transition to multi-tariff accounting is absolutely not necessary for him. You can turn on the washing machine after 23 hours, when you are already sleeping, but you do not control the process, and one water leak in washing machine, if your neighbors and yourself have to re-do repairs, it will “eat up” all the savings from the “nightly” tariff for many years.
Additional parameters of the electric meter
I will briefly describe the various additional parameters and functions of electricity meters. Electricity meters vary according to the operating principle: on electronic and induction, many mistakenly believe that if the electric meter for an apartment is electronic, then it is obviously more accurate than an induction one, but this is not so. If an electric meter has the same accuracy class (error), for example 1%, then these electric meters will count the same with an error of up to 1%.
Currently, there are many additional characteristics and electricity meter options for an apartment, house - this includes displaying various information on the display (date-time, parameters electrical network, power value, electricity growth per month, year, etc.), storage of electricity values for several months, electronic passwords, remote connection and reading of electricity meter readings via digital interfaces, GSM modem, using an optical port, and much more.
It is clear that the more sophisticated the electric meter for an apartment or house is, the more expensive it is. The leading manufacturers of electricity meters have enough big choice, from the simplest induction electricity meters for several hundred rubles, to electronic ones with all sorts of bells and whistles for several tens of thousands of rubles.
Also, when choosing an electric meter, pay attention that the electric meter for the apartment is included in the State Register of Measuring Instruments of Russia (State Register), i.e. an electric meter for an apartment must be “approved” by Russian standards in the field of metrology. Each measuring instrument that meets Russian standards is entered into the register under its own unique number.
Let's highlight the main parameters to choose the right electric meter for your apartment:
- Single-phase or three-phase.
- Entering the electric meter into the State Register of Measuring Instruments.
- According to the installation method in the electrical panel.
- The date of issue (verification) is no more than 2 years for single-phase and one year for three-phase.
- The maximum current of the meter is greater than the input circuit breaker.
- Accuracy class is no more than 2 (for the public), for legal entities - no more than 1.
- Single tariff or multi tariff.
Thank you for your attention.