Let's look at this creation of engineers as a human assistant, and not as a required condition housing and communal services and the state. Many residents of our huge country do not see the advantages of metering devices, but they were invented precisely for the benefit of humans. Let's look at the pros and cons of this invention.
Which water meters are more suitable for residential and industrial premises
Every year, people increasingly look into their pockets, or rather into their wallets! A person understands that the time has come to save and give away excess family budget doesn't want to. For example, he no longer goes to the market for groceries, but to the supermarket, and the same with cold and hot water- why pay to housing and communal services and all these “honest” organizations, if you really look at how much money they counted, you would think that a herd of elephants lives at home and everyone bathes all day long. For this purpose, they came up with an accounting system, the indicator of which is cold and hot water. Let's find out which water meters are best to install at home.
What are counters for?
- allow you to independently control your fluid consumption
Allows you to save your family budget
Types of meters
In fact, there is a very diverse classification of these “devices”. Let's look at the standard ones.
Mechanical with mechanical system measurements (cubic meters) of liquid consumed.
Mechanical with a built-in sensor for signal transmission.
Electronic (the advantage is that you can take readings from the meter remotely)
Modular and capsule (intelligent - the most accurate)
Intelligent water measuring devices and their advantages
If there is a need for precise measurements, choose smart ones, since compared to other “miracle devices” they are more accurate.
Very high accuracy of liquid flow metering
Design without unnecessary wires and unnecessary details as they say “nothing extra”
Fixes various errors during operation
Very high degree meter protection
What types of counters are there?
Tachometer
Some of the most popular, available among the people, serve for more than 10 years; it is very convenient to install such a meter.
Tachometers are divided into 2 types
Single-jet - the consumption of water is taken into account when the jet hits the impeller, which rotates accordingly. Inside there are magnetic elements that serve to transmit readings to the indicator (scoreboard). Everyone knows that the mentality of the Russian people forces them to come up with bells and whistles that allow them to deceive the readings, but for this type of water measuring device it is possible to install an antimagnetic film.
Multi-jet - there is one big difference from a single-jet water measuring device; multi-jet ones are more accurate in readings, since several small streams of water serve to compile the correct readings on the indicator. If you need accuracy and ease of maintenance and installation, then take away your doubts with tachometer multi-jet counters.
There is one more separate species - turbine systems, They do not have an impeller for calculating the water consumed, but a small turbine. Well suited for unstable fluid pressure, for industrial purposes - of course, turbine ones, they serve to withstand large pressure drops.
Electromagnetic water measuring instruments
We can say that they are the most accurate among all the others; the principle of operation is based on calculation using the speed and area of liquid flow. Thermal (temperature) effects and water density do not affect the calculation of readings.
- very high accuracy of readings
- impurities and additives THAT ARE IN THE WATER CAN AFFECT THE ACCURACY OF THE READINGS OF SUCH A DEVICE, AFTER SUCH A PROCESS, the meter may fail early.
Distorts readings when working with very clean liquids
Since the device directly depends on electricity, there may be unplanned failures in the operation of such a device due to lack of electricity.
Subtleties of choosing counters
When purchasing meters for cold and hot water, carefully inspect the integrity of the entire surface of the meter, pay attention to the glass (it breaks during transportation)
Check for the correct GOST standard R. 50601, R. 50193
To install meters, use a special service that installs meters, since only they can do everything according to the standard (many self-taught people damage devices and Additional materials during self-installation)
Choose your water meter based on individual characteristics the place where you live and what you expect. Always read, always learn, learn everything!
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 electric meter, but here it is at the discretion of the 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 machine it will be indicated maximum current. 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 or 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 (in old housing stock) with an accuracy class of 2.5, but according to the law, it is high time to replace them with a higher accuracy class. 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 tariff T-1, 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 house’s electric heating 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 you have to re-do the repairs for your neighbors and yourself, 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 electricity meter for an apartment or house, 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.
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 current up to 50 amperes, accuracy class no worse than 2.0, with DIN rail mounting, no more than two years have passed since the verification date!"
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 direct for 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 calculate 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 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).
Or a residential building without a sealed electricity meter, which gives us information about our electricity consumption. What are they and under what conditions are they used? To find out more about them, read this article.
Why do you need an electricity meter?
Electricity meter- a device designed to measure energy consumption by a consumer.
Meters measure direct or alternating current in kW/h or A/h. They are needed primarily for those consumers who want to connect to the power grid on a completely legal basis. Correct and legal connection of power supply and accounting of electricity consumption using electricity meters provides consumers with significant savings and allows them to plan their expenses based on the readings of these devices.
What types of electricity meters are there?
There are three-phase and single-phase, as well as electronic and induction counters electrical energy . They can be connected to the network without current transformers (called direct connection meters) or with the help of transformers (indirect connection meters).
Electricity meters for currents from five to twenty amperes are used in networks up to 380 V. Nowadays they mainly use induction and electronic types. Induction electricity meters are well known to us all because they became widespread back in the 90s and were used quite a long period time.
On the front panel of the induction electric meter, the number of revolutions of a special plate is indicated, which corresponds to the consumption of 1 kWh of electrical energy. It may indicate that 1 kWh corresponds to 1200 revolutions.
Which counter should I choose?
A reasonable question arises: which counter should you choose for yourself and what are the advantages of each of the above types? In order to accurately determine the choice of any type of meter, it is necessary to clearly understand for what purposes it will be used.
The fact is that with the development of technology, new opportunities appear that significantly simplify and improve the scope of use of the device. You need to decide how much of these features you need. And how much are you willing to pay for these new amenities.
Induction
The essence of the work electricity meter induction type consists in the interaction of forces that are formed as a result of the operation of inductance coils with the magnetic forces of the meter indicator disk. As a rule, it is made of aluminum, and the number of its revolutions determines the consumption of electrical energy using a special recording mechanism.
Electronic
Despite the fact that induction meters are an outdated metering technology, many consumers are in no hurry to change them to electronic ones, which have a number of significant advantages, but have a higher cost. The principle of their operation is that these meters operate on the basis of electronics and do not include moving parts in their design. They transmit pulses from measuring elements, converting them into generally accepted electricity metering values. Compared to induction meters, such electricity meters have increased reliability and measurement accuracy. They may also have a number of those described above additional functions, as accounting at different tariffs and provide remote transmission of accounting information.
The last function eliminates the influence human factor into the accounting process and is especially interesting for regulatory organizations.
Basic parameters of the electric meter
Accuracy class
The most important parameter of an electric meter is the so-called “Accuracy Class”. It talks about the maximum possible error in measurement. Induction meters, which were used until the mid-nineties, had this indicator at 2.5. This meant that the maximum level of error was 2.5%. Then in 1996, a new standard of accuracy class was introduced, which was 2. This caused a massive replacement of home meters with more accurate ones.
Two tariffs
It is impossible not to mention the multi-tariff accounting function. Not so long ago everything electricity meters, which are used in the domestic sphere, supported accounting at only one tariff. Modern devices allow you to keep track of electricity at once according to several tariffs and even seasons. This allows you to save on electricity by using electrical appliances in the most profitable schedule. In this case, the electric meter independently makes the transition from one tariff to another without human intervention.
As a rule, when using two-tariff rates, a time frame is determined for each of the accounting modes, for example, from 7 to 23 - a day rate, and from 23 to 7 - a night rate. If, for example, energy supply company decide to offer discounts only on weekends, then only those consumers who have the appropriate meters will benefit from this. For industrial consumers, multi-tariff electricity metering is an opportunity for serious savings on production costs.
In new houses under construction, the practice of connecting electronic multifunctional meters already at the construction stage is widespread.
If you have installed electricity meter old model, then you can completely replace it with a new, electronic one and enjoy all the benefits it provides.
Electricity meters verification
Over time, the meter parts wear out, and there comes a time when the device must be checked for measurement accuracy and, if necessary, replaced. This period is counted from the date of release of the device and is called the inter-check interval. This interval is indicated in the electric meter passport.
As a rule, the better and more expensive the electricity meter, the longer its test interval and the longer the warranty period. The manufacturer's warranty and the availability of certified repair shops are also essential.
Power supply design
We will advise you about your power supply system, or. We provide consultations free of charge and will be happy to perform high-quality work for you and agree on it in supervisory authorities, as well as carry out designer supervision.
In the ones we develop, we recommend only high-quality and proven models electricity meters, which are well agreed upon by the Energy Supervision authorities and do not cause problems during operation. Great experience allows us to confidently recommend models that have the best value/quality ratio. There is no need to overpay for unused features.
IN modern world You can no longer do without these devices. After all, everyone in their house has electrical wiring, therefore, there must be an electric meter. But here's the problem. As soon as the time comes to replace or, we go to the store and are bombarded with a barrage of variety of choices. We start to get lost and end up choosing the wrong thing. To prevent this from happening, let's figure out what types of counters there are and which one is right for you. Today there are two main types of meters: induction (mechanical) and electronic.
Induction (mechanical) electricity meters
Fig.1. Induction single-phase electric meter
Counters with a rotating disk are familiar to almost everyone. These are the ones that have a rotating wheel behind the transparent panel. Surely many have observed the speed of its rotation more than once - the higher the speed, the greater the energy consumption. And the counter readings are indicated by numbers on special reels.
Principle of operation of such counters is as follows. IN electric meter there are 2 coils (Fig. 2 - 1 and 4 indicators) - voltage coil (serves as a limiter alternating current, a barrier to interference, etc., creates a magnetic flux commensurate with the voltage) and a current coil (creates an alternating magnetic flux commensurate with the current).
Fig.2. Operating principle of an induction electric meter
The magnetic fluxes created by the coils penetrate through the aluminum disk (Fig. 2, pointer 5). In this case, the flows that the current coil creates penetrate the disk several times due to its U shape. As a result, electromechanical forces appear, which rotate the disk.
Next, the disk axis interacts with the counting mechanism in the form of a worm (gear-screw) transmission (Fig. 3), which transmits the necessary signals and information to the digital reels. The higher the disk torque, the higher the power of the supplied signal (the torque is equal to the power of the network), and therefore the higher the power consumption.
Fig.3. Worm-gear
When the power of the supplied electromagnetic signal decreases, the permanent magnet braking (Fig. 2, pointer 3). It evens out fluctuations in the disk rotation frequency due to interaction with vortex flows. The magnet creates an electromechanical force that is opposite to the torsion of the disk. This causes the drive to slow down or stop altogether.
This group of meters is the cheapest and simplest. Induction electricity meters were widely used in Soviet time(and to this day, most apartments have just such devices installed). But gradually they are being replaced by electronic meters due to a number of disadvantages of induction devices. For example, induction electricity meter cannot take readings automatically, and there is often an error in the readings.
Advantages and disadvantages of induction meters
Advantages
- Reliable to use
- Long-term service life of the meter
- Independence from power fluctuations
- Cheaper than electronic ones
Flaws
- The accuracy class is quite low - 2.0; 2.5
- There is practically no protection against theft of electrical energy
- High self-current consumption
- At low loads the error increases (than less class accuracy, the greater the error)
- When metering several types of electricity (active and reactive), there is a need to use several energy metering devices
- Energy metering is carried out in one direction
- Large dimensions of devices
Electronic electricity meters
Fig.4. Electronic electricity meter
These devices are somewhat more expensive than induction ones, but today they are the most profitable and priority meters to use. They have a higher accuracy class and allow multiple tariffs to be taken into account.
Electronic electricity meters work by converting the analog input signal from the current sensor into a digital code equal to the power consumption. This code is sent to a special microcontroller to be decrypted. After that, the amount of electricity consumed is displayed on the display (or digital drum).
The most important component of these counters is the microcontroller. It is he who analyzes the signal and calculates the amount of electricity consumed. It also transmits information to the output electromechanical devices and display.
Fig.5. Operating principle of an electronic electricity meter
The device itself consists of a housing, a current transformer, a signal converter and a tariff module. If we look at it in more detail, the meter also includes:
- LCD (or digital drum)
- secondary power supply (converts AC voltage)
- microcontroller (calculates input pulses, calculates consumed electricity, exchanges data with other nodes and meter circuits)
- converter (converts analog signal to digital and then converting it into a pulse signal equal to the energy consumed)
- supervisor (generates a reset signal in case of power failures, outputs an alarm signal when the input voltage decreases)
- memory (stores electricity data)
- telemetry output (receives a pulse signal about energy consumption)
- real time clock (counts the current time and date)
- optical port (reads meter readings and also programs it)
Advantages and disadvantages of electronic electricity meters
Advantages
- Accuracy class - from 1.0 - high
- Multiple tariffs (from 2)
- One meter is enough to account for several types of electrical energy
- Energy accounting is carried out in 2 directions
- Measures the quality and volume of power
- Store electricity metering data
- Data is easily accessible
- In case of electricity theft, unauthorized access is recorded
- Possibility to take readings remotely
- Can be used for automated technical accounting and control of electricity metering (ASTUE and ASKUE)
- Long term metrological interval (MPI)
- Small in size
Flaws
- Very sensitive to voltage changes
- More expensive than induction
- Quite difficult to repair
Markings on electricity meters
In addition to the types of meters, there are several more nuances that you should know. Any electric meter has a certain marking, conventionally designated by letters and numbers.
Fig.6. Symbols on the electric meter
| Designation | Explanation |
|---|---|
| WITH | Device type (meter) |
| A, R | Type of energy taken into account (active energy/reactive energy) |
| ABOUT | Single phase meter |
| 3, 4 | Number of phase wires in the network (four-wire/three-wire) |
| U | Versatility |
| AND | Type of measuring system ( induction meter). Next may be three-digit number, which means the design of the meter (the design of the meter can be induction or electronic). |
| T | Tropical meter type |
| P, M | Type of execution (direct-flow - if there is no connection to a transformer / modernized). Further abbreviations may be such as "380/220 17A, 2001", which means the operating voltages in the wires, the maximum current flow and the year of manufacture. Also at the end of the inscription there may be factory number. |
As for the accuracy class of the electric meter, these parameters determine the accuracy of the readings of consumed electricity. Apartments, as a rule, have class 2.0 meters installed, but they can be higher. What does this mean? And the fact is that your electric meter can take into account 2% more or less electricity from its own power. Or, more simply put, the meter error. The smaller the number, the smaller the error. Overall, in living conditions An electric meter of class 2.0 is sufficient. More high classes precision is needed more in enterprises where high energy power is needed.
So, today we don’t have to limit ourselves in choosing electricity meters. Each of them has its own specific features and functions. In this article, we examined the main features of these devices and the principles of their operation, which will help you navigate the variety of choices.