A very important indicator of saving money at home is reducing the cost of paying for electrical energy. In the modern world, household appliances have high power, which certainly hits the pocket when the monthly receipt for electricity arrives. Next, we will look at which electricity meter is better to choose and buy for an apartment or private house, so that monthly receipts are less and less!
Type of devices
First, let's briefly understand what types of electricity meters there are, after which we will find out which one is needed for a house, apartment and cottage.
So, today there are the following types of metering devices:
- Induction (mechanical) and electronic. The first ones are classics of the genre and are still used in buildings of the old type. The advantage of induction electricity meters is durability, reliability and low price. At the same time, the main disadvantage is the low accuracy class, as a result of which you can either overpay extra money or underpay. In turn, electronic metering devices are multifunctional, can be designed for several tariffs, and are also better in that they take up less space on the input panel. As you understand, the disadvantage is the higher cost and shorter service life, which discourages buyers. You need to choose the type of meter based on your financial capabilities. We talked about how one and the other option works in the article:.
- Single-tariff and multi-tariff. There has already been a whole discussion here among owners of meters with two/three tariffs and ordinary single-tariff meters. We have already looked at where we provided both negative and positive customer reviews. We repeat once again that the rationality of choosing an electric meter for several tariffs depends on the region of residence and on what household appliances You use it more often. If you have a nocturnal rhythm of life, it is better to choose and buy a multi-tariff meter for your home and apartment.
- Single-phase or three-phase. Everything is simple here and the choice of meter depends on the type of power supply to your home or apartment - single-phase or three-phase.
- . This characteristic shows the percentage error of the electricity meter when accounting for electricity consumption. Today, it is necessary to use devices with an accuracy class of no lower than 2.0 (according to Decree of the Government of the Russian Federation dated May 4, 2012 N 442 (as amended on June 22, 2019), see Rules for organizing electricity metering in retail markets. p. 138 ). The more accurate the accounting, the less likely it is to be deceived when paying for light.
- Power.Another equally important characteristic that must be taken into account when choosing an electricity meter is the total electrical load (power). Market electrical products offers direct connection meters in the current load range from 5 to 100A. We talked about this in a separate article.
- Mounting method. The housing can be mounted either on or with bolts.
- Conditions of use. There are devices intended for use only in heated rooms, and there are outdoor models. Meters must be operated under the conditions specified in the metering device's passport.
A short video review on choosing an electric meter for a home or apartment:
Expert advice
Which option should you prefer?
So, we have provided the types of electrical networks, now let’s talk about which one is better to choose and buy for your house, apartment, garage and cottage.
Firstly, rely on power characteristics metering devices. In order to choose the right electricity meter for power, or rather current, you need to calculate what electrical appliances you will use. Modern household appliances have nominal values (in kW) indicated in their passports. Sum them up and take into account the stock (in case you buy something else), on the basis of which you make a decision on choosing a certain characteristic. If the total is no more than 10 kW, buy a 60 A model, which will be quite enough. If the average daily power consumption is more than 10 kW, it is better to choose a 100 A electricity meter. Usually for a house and apartment 60 A is enough. 
Secondly , decide on the type of device– mechanics or electronics, one tariff, two or three. Here, again, you are your only advisor, because... Everyone has their own preferences and financial capabilities. If difficulties arise at this stage, consult our specialists in the “” category. We recommend that you choose only single-tariff electricity meters for your dacha, because once a week (or even a month) is not correct, given that the rest of the time you will overpay for the daily rate. 
Third, choose the right one fastening type. Here we recommend choosing a model that is mounted on a DIN rail, because... it is universal - when you buy an adapter strip, you can fix the case on the wall too.
Well, the last thing that should be said is manufacturer. High-quality electricity meters are produced by domestic companies, such as Incotex (the popular Mercury model), Concern Energomera, Leningrad Electromechanical Plant and the Moscow Electrical Instruments Plant. Elster Group, ABB and General Electric are popular among foreign companies. As for which electricity meter is best to choose based on manufacturer, we recommend actively reviewing reviews of various models on the forums. Best rating quality can only be given by someone who has already used one or another model.
Rating of the best electricity meters 2019
In 2019, according to reviews from customers and companies that sell electricity meters, the following models are the best today:
- single-phase, single-tariff: Energy meter CE101 R5, Neva 103/5 1s0, ABB FBU11200, Mercury 201.8, ;
- single-phase, multi-tariff: Energomera CE 102 MR5, Neva MT 114, ABB FBВ 11205-108, Mercury 200.2;
- three-phase, single tariff: Energomera SE300, Neva 303-306, Neva MT 324, Mercury 231 AM-01;
- three-phase, multi-tariff: Energy meter CE301, Mercury 231 AT-01.
And finally, I would like to tell you how to choose the right electricity meter. By adhering to the following recommendations, you will definitely be able to choose and buy the most suitable model:
- For a garage, purchase a more powerful metering device, because... very powerful equipment can be used here, and several types at the same time: welding machine, compressor, etc.
- Check the date of verification of the meter (indicated in the attached passport), as well as the presence of seals on the case. The state verification date should be no more than two years old for single-phase devices and no more than a year for a 3-phase electric meter.
- Don’t listen if they tell you to overpay and buy a device with automated consumption accounting. This function will not change anything for the better for you, because... it only helps the power companies track the readings, while you have to pay the extra money.
- Russian manufacturers produce products of no less quality than foreign ones. Take a good look at the domestic models, read reviews on thematic forums and choose a cheaper, but still reliable option for an electricity meter.
- Also read on the Internet about how expensive it is to repair the electricity meter you have chosen, because... sometimes service prices are simply astronomical in relation to a particular company.
- A small but very important nuance - before purchasing, inquire about the noise level of the electric meter, so that after installation you will not be upset by an unpleasantly buzzing device.
- Electronic devices have a longer calibration period than induction devices. You can learn more about this from our article.
- Mechanical equipment can be “rewinded”, unlike modern electronic equipment. This, of course, is prohibited by law, but nevertheless our people do not stop.
- If you decide to choose a mechanical electric meter, check it before purchasing. This is done as follows: spin the disk by hand and if it rotates by inertia, it means that the movement is normal and the mechanism is suitable for operation. Any irregularity in movement indicates that the wheel is not in working condition.
So we have provided all the basic tips for choosing an electricity meter, as well as a rating the best electricity meters for 2019. We hope that now you know which option is better to choose and buy for your conditions!
Expert advice
The decision about which electric meter is best to install in an apartment must be made at an early stage of planning the installation of electrical equipment.
Once you have purchased the device, you will not be able to return it, since the equipment passport contains a mark that includes the seal of the government agency and the serial number. The only situation when returning an electric meter is possible is a manufacturing defect.
Criterias of choice
When choosing an electric meter, you will have to rely not on personal preferences, but look for a device whose characteristics are suitable for the parameters of a particular electrical wiring.
Significant characteristics of the electric meter:
- type of design;
- number of phases;
- device current class;
- presence or absence of multiple tariffs;
- accuracy of electricity consumption calculations;
- method of fixing the device;
- terms of Use;
- date of manufacture;
- time of last reconciliation;
- interverification interval.
The defining parameters include the first four from the list above. Other criteria are secondary.
Type of design
It is better to start the story about how to choose an electricity meter for an apartment with information about the technical device of a potential purchase.
There are three types of electricity consumption meters:
- Induction meters. These are mechanical counters with a rotating disk. The advantage of induction devices is their long service life and low cost. A significant flaw in the mechanics is the insufficient calculation accuracy. The device can operate both negatively and positively compared to actual energy consumption. Induction equipment operates only on a single-tariff principle.
- Electronic meters. This equipment is distinguished by metering accuracy and compactness. Electronics allows you to work in multi-tariff mode (you can choose from one, two or multiple tariffs). The main disadvantage of electronic devices is their relatively short service life. Electronics are more expensive than mechanics, which together makes the purchase even more dubious for many.
- Combined (hybrid) electricity meter. This is an intermediate option between mechanics and electronics. The device interface is executed in digital form. The measuring part can be either electronic or inductive. The computing unit is always mechanical.
When choosing counting equipment, it is recommended to proceed from electricity consumption. Electronics are relevant at high consumption rates, when inaccuracies are fraught with significant financial costs. In some cases, electronic meters pay for themselves in a couple of months due to more accurate counting.
The possibility of multiple tariffs should be taken into account: not all regions have different electricity prices throughout the day. And even if the prices are different, the low electricity consumption negates the arguments in favor of buying an electronic device.
Number of phases
Based on the number of phases, there are two types of devices:
- Single-phase.
- Three-phase.
When choosing, you should proceed from the existing wiring: for single-phase wiring - 1 phase, for three-phase wiring - 3 phases.
Note! IN apartment buildings Single-phase devices are always installed. When purchasing a meter for a private home, you can figure out the number of phases by paying attention to the wiring. If there are 2 wires in the power line, you will need a single-phase meter; for a line with 4 wires, you need a three-phase meter.
Each electric meter has terminals with which current-carrying conductors are connected to account for electricity. The single-phase device is equipped with 4 terminals: 2 phases and zero for the input and two for the output. Connecting a single-phase device to a three-phase power line is not possible. If, when purchasing a single-phase device, a mistake was made with phase counting, you cannot do without a new trip to the store.
A three-phase electric meter has 8 terminals (at least). For input, 4 terminals are used (3 per phase and 1 for zero) and the same number per output. For a single-phase line, you can also use a three-phase device, but in this case half of the terminals will not be used.
Device current class
Single-phase models are used to calculate electricity consumption in circuits where the current is in the range of 5 - 80 A. Three-phase devices are designed for circuits in the range of 50 - 100 A. Some equipment modifications also work with a smaller spread: a smaller range makes the device cheaper.
When choosing an electric meter, you need to proceed from the thickness of the cable going into your home. The table below shows the maximum current for copper and aluminum conductors of different thicknesses. No more current is required than the value indicated in the table. Please note that the Electrical Installation Rules (ELR) regulate the installation of electrical appliances depending on the type of electrical wiring (closed or open) and the number of phases.
As an example, we can cite the situation with single-phase open-type electrical wiring with a copper wire. The wire cross-section is 6 square millimeters. In this case, you will need a meter with a maximum current of 50 A. If we are talking about an aluminum wire, the current will be 39 A. There is no point in overpaying for a larger range, since the power supply automatically turns off at 39 A.
Note! At closed type electrical wiring, the current strength for a copper wire will be 34 A, and for an aluminum wire - 38 A.
Presence or absence of multiple tariffs
There are 3 types of equipment available:
- Single tariff.
- Two-tariff.
- Multi-tariff.
Payment for electricity consumption for a single-tariff device is calculated based on the principle: electricity consumed per month is multiplied by the price per 1 kWh.
Calculation example for single-tariff equipment:
- Consumption - 200 kWh.
- Price per 1 kWh. - 5 rubles.
- Financial expenses - 200×5=1000 rubles.
In two-tariff models, the cost of consumed electricity is calculated based on the time of day:
- Day rate (from 7 am to 11 pm). The cost of a unit of electricity is 1–20% higher than the nominal value. The nominal value is understood as the cost established in a single tariff.
- Night rate (from 11 pm to 7 am). The cost of 1 kWh is 20–60% less than the nominal value.
Example of calculation for a two-tariff plan:
- The price of electricity at the daily rate is 3 rubles per 1 kWh. 100 kWh consumed per month.
- The price of electricity at night tariff is 2 rubles. Monthly consumption - 150 kWh.
- Total monthly electricity costs: 100×3+150×2=600 rubles.
- Savings when using a two-tariff meter are 150 rubles or 20%. With one tariff, the costs would be: 250×3=750 rubles.
Note! All figures are provided as an example only. Each region has its own tariffs and discount levels. Specific information can be obtained from the energy sales organization at your place of residence.
If a multi-tariff plan is selected, the day is divided into 3 parts:
- Night (from 11 pm to 7 am). The cost per 1 kWh is 20–60% less than the nominal value.
- Half peak (from 9 am to 5 pm and from 8 to 11 pm). The cost of 1 kWh is identical to the nominal one.
- Peak (from 7 to 9 am and from 5 to 8 pm). The cost of 1 kWh is 5–30% more than the nominal value.
Savings on using 2 or more tariffs are possible in the following cases:
- Significant difference between tariffs.
- Focus on energy consumption at night.
If it is not possible to use powerful energy consumers at night or at least during half-peak, purchasing dual-tariff or multi-tariff equipment will not justify itself. Costs will increase as the peak tariff is higher than nominal.
Electricity metering accuracy
This parameter depends on the accuracy class (CT) of the electricity meter - this is the maximum permissible deviation during the measurement of electrical energy as a percentage. The smaller the number, the higher the accuracy class.
Electrical installation rules regulate the possibility of installing devices with an accuracy class of at least 2 units. Until recently, devices with accuracy class 2.5 were allowed. There are devices on the market with a wide variety of accuracy classes - up to 0.5. However, the higher the accuracy class, the more expensive the equipment.
Note! The accuracy class can be seen in a special circle on the body of the electric meter. The error is indicated as a percentage.
There is an opinion that a less accurate device will record less electricity consumption. However, this is only true if the equipment errs on the downside. In practice, with the same probability, everything can happen the other way around.
For example, with real electricity consumption of 100 kWh and an error of 2%, the deviation will be 2 kWh per month. To a lesser or greater extent - it is impossible to predict. The indicated value (2 kWh) is insignificant, but if we are talking about consumption of thousands of kWh, installing the most accurate device can provide very significant savings.
Device fixation method
According to the mounting method, meters are divided into 2 types:
- Attached to DIN rail.
- Fixed to a shield, which can be made of metal, plastic or wood.
The method of fixation is not a fundamental issue and you can choose the option that is most suitable in this particular case.
terms of Use
Accounting equipment can be installed in the following locations:
- Interior of the building (heated room).
- Outdoors or in a cold room. There is equipment whose operation is possible at low and high temperatures, in conditions of precipitation.
Note! If the meter is located on the street, it must remain freely accessible. This is an important condition, since you will need to take measurements of electricity consumption.
Date of manufacture and time of last verification
According to the PUE, the maximum period elapsed from the date of manufacture of the device to installation is:
- for single-phase devices - 2 years;
- for three-phase devices - 1 year.
If more time has passed than required by the regulations, you will need to check the accuracy of the readings in a specialized organization. Verification is carried out at the expense of the electricity consumer. If you do not pay attention to the date of manufacture of the equipment, an unscrupulous seller may sell a product that cannot be installed without prior verification.
Any meter presented on the domestic market is verified by a state regulatory organization. If the testing is passed, the device is sealed and allowed for sale.
When purchasing, you need to pay attention to the seal: it should not be damaged. Even if there are small chips on the seal, installation of an electric meter will be refused.
Calibration interval
This indicator indicates the period after which equipment verification is mandatory. For induction devices, the verification interval is 16 years, but for electronic devices it is 3 years or more.
If necessary (for example, if there are doubts about the accuracy of the metering), the electric meter can be checked unscheduled. Payment for verification falls on the shoulders of the customer. However, if the fault is confirmed, a new consumption count begins. The new date is indicated on the seal.
Other factors when choosing a meter
A few more factors that you should pay attention to when choosing equipment for metering electricity consumption:
- Automatic consumption metering. The option is attractive for those users who do not have the time to take readings on their own.
- Country of manufacture. At the moment, Russian devices are considered to be not inferior in quality to foreign ones. Products from companies such as Intcotext and Energomera are popular among consumers.
- Repair prices for a specific model. Most often, repair work costs less than purchasing and installing a new device. However, repair prices can vary quite a bit depending on the model.
- Noisy operation. Some models make a buzzing sound when operating. This creates discomfort, so it would be a good idea to ask the seller about the noise level of the device.
Some buyers prefer induction meters since this equipment allows “rewinding” of flow. However, now the time has come for new induction models that have a magnetization indication function. The inspector will notice if the indicator goes off, which will lead to charges of electrical theft.
Conclusion
It is easier for an informed person to decide on the purchase of an electric meter - he understands what he wants. Such a buyer comes to the store and makes clear demands for the purchase. An appeal to the seller may sound, for example, like this: “I need an electronic multi-tariff single-phase meter for installation in an apartment. A range of 5 – 50 A, an accuracy class of 0.5, a verification interval of at least 5 years and fixation on a DIN rail are required.”
- induction (mechanical). They have a fairly simple design. One of the coils in such a device is connected in parallel to the AC mains, and the other is installed in the circuit between the generator and the load (current winding). Electricity flowing through the windings creates magnetic fluxes that act on the movable disk. An electromechanical force arises in it, creating a rotating moment. Electricity consumption is proportional to the number of disk revolutions, which are used to keep records.
- electronic electricity meters. The operating principle of such a device lies in the processing of analog incoming signals into counting pulses. Alternating current acts on the solid-state elements of the meter, causing pulses to appear at the output. Their number is proportional to electricity consumption.
Electromechanical meters are called induction meters. In electronic ones, an electromechanical mechanism can also be installed. It is advisable to buy an electronic electricity meter with such a counting mechanism when the meter is installed in a cold place outside the house.
Meters are also categorized by:
- accuracy class;
- the number of phases in the networks to which they are connected;
- number of measuring elements;
- the principle of inclusion in electrical networks;
- types of measured power and energy;
- designs.
There are single-tariff and multi-tariff meters.
Number of tariffs
There are single-tariff metering devices that count consumed electricity all the time at one tariff, and their multi-tariff counterparts that conduct differentiated metering.
They have one or more tariffs and “turn on” each of them at certain times. The most common version of such a device is a two-tariff electricity meter, in which during the daytime consumption is calculated as usual, and at night - at a reduced tariff. In three-tariff meters, the night period, peak and half-peak zones are distinguished.
Important to know when choosing an electric meter
Before you buy an electric meter for your apartment or house, it is important to know how to choose the right device. Main criteria:
- accuracy class. It is better to purchase devices with a lower indicator;
- inter-verification interval - the longer it is, the better;
- mounting method: three screws or DIN rail;
- number of tariffs. Multi-tariff electricity meters help you save by metering electricity at a cheaper nightly rate.
Consider also the cost of the device. At Direct-Electric you can purchase an electricity meter for a price starting from 520 rubles.
Before you figure out which electric meter to choose, you need to consider the design of the electric meter and the principle of its operation. We will not go into technical specifications, but will outline the defining parameters that you should pay attention to.
Electricity meter selection parameters
The maximum current for which the meter is designed.
Sometimes the question arises of how to choose an electricity meter based on current; the solution is quite simple - read on. Single-phase meters are used mainly for powering apartments, private houses and small office and retail premises. The rated power of such networks is in the range of 3-7 kW (the maximum value is given for apartments with electric stoves) at a voltage of 220V. Considering that 1 kW of power corresponds to a circuit current of approximately 4.5 A, we obtain a current for which the meter should be designed at 13-32 A. The current for which the meter is designed must be no less than the calculated one.
On the front panel of any electric meter, even if you have lost the passport for it, its main characteristics are always indicated, including the rated and maximum current, for example: 5-40A, which means the rated current is 5 amperes, the maximum is 40, respectively.
Electric meter accuracy class
Before July 1, 1997, there was a 2.5 standard for electricity metering. This meant that the accuracy of the electricity meter, namely measuring electricity consumption, was 2.5%. After this time, the use of such devices was banned, and a new standard 2.0 was introduced. To install a device with such an error in an apartment, it is quite enough. Electronic meters are produced with a measurement accuracy of up to 0.5%, which is even more consistent with modern requirements.
Which electric meter to choose - electronic or induction?
The models of meters today are dizzying. But it is better to opt for electronic electricity meters, as they have undoubted advantages over induction, as well as hybrid ones, which exist today as a transitional option.
In addition to those already known to us (Energomera, Incotex and MZEP), electronic meters are also manufactured today in Russia by the Nizhny Novgorod Plant named after M.V. Frunze", "Leningrad Electromechanical Plant". The production of meters from these manufacturers accounts for more than 80% of all produced electricity meters. We will not consider foreign-made meters for now due to the difficulties that arise with their repair, if necessary.
Basically, most consumers today are concerned about electricity meters for apartments and houses, as well as small commercial and industrial enterprises.
Electricity meter test data
Today, absolutely all electricity meters included in the state register comply with current standards in terms of their metrological characteristics. However, sometimes, to select products, a certain country conducts an independent examination of individual samples in its laboratories.
Thus, according to the magazine “News of Electrical Engineering” No. 1(31) and 2(32) for 2005, at the end of 2004 several types of electricity meters from Russia, Belarus, Ukraine and Lithuania were tested in Belarus. Russian metering devices were presented by three companies. The first ones are already familiar to us:
- Energomera (Stavropol)
- JSC MZEP-1 (Moscow)
- Nizhny Novgorod plant named after M.V. Frunze (Nizhny Novgorod)
Without going into the intricacies of the examination, we immediately note that the metrological characteristics of all presented electricity meters were found to comply with GOST.
The fact that Belarusians chose two of the three companies we were considering - manufacturers of electricity meters - for examination speaks volumes. To be fair, we note that Incotex began producing electric meters only in 2001. Before this, its main products were cash registers.
Of course, this is not 2004, and yet...
Which electric meter to choose - consumer reviews
At one forum in April 2013, there is a conversation about choosing a meter. The energy supply organization of St. Petersburg is forcing a forum member to replace the “grandfather”, which he has been using for n number of decades, with a new one. A forum member asks:
People! Which counter to choose?!
Leads possible options, where 7 pieces are St. Petersburg electricity meters, 2 pieces are Energomer meters.
The guy from Petrozavodsk clearly advises Energomer, citing the fact that while working in a sales company, he has extensive experience in selling electric meters, and also a year ago he purchased an electric meter from the above-mentioned company, and believes that he was right. Although he still prefers Mercury.
At the same forum, we are also talking about the fact that locally, in particular in St. Petersburg, energy supply companies are trying to “introduce” devices from local manufacturers, obviously being in cahoots with them.
In the following articles we will try to look at some electric meters from other manufacturers, and we will also try to select certain brands that are most suitable for installation.
We will send the material to you by e-mail
Scientific and technological progress does not stand still, offering more and more new measuring and control devices. But Russian residents are in no hurry to throw away old models, still using them to this day. This fully applies to such measuring equipment as electricity meters. Stores are filled with counters of different shapes, sizes and designs. But they are all divided into two groups: induction and electronic. Therefore, when the question is asked which electricity meter is best to install in an apartment, you will have to choose from these two. In today's review, we will look at the positive and negative aspects of operating the two types and analyze their prices.
Electricity meters: induction (1), electronic (2)
Both models are strikingly different from each other. This also applies appearance, and internal design, and operating principle. And if induction models are a dial with rotating numbers, then electronic ones are a display displaying indicators in the form of electronic light numbers. And this is just an external difference. Now, how do they differ purely structurally?
Induction electricity meter
The operating principle of this device is based on two coils. The first of these is the voltage coil. Its main functions are to limit the actions of alternating current, or rather, to block interference. It is this coil that generates the flow magnetic field, which corresponds to the network voltage.
The second is the current coil. It creates in the device alternating current, which in terms of its indicators is equal to the current in the network. When two coils operate, a magnetic field is formed that acts on a disk made of aluminum. Under the influence of the field, electromagnetic forces are generated. They then rotate the disk, on the axis of which the counting device is fixed. The latter is based on a worm gear, through which rotation is transmitted to the dial. The more powerful the signal inside the magnetic field, that is, the greater the electricity consumption, the faster the disk spins.
It should be noted that induction devices are gradually being phased out. But statistics show that there are several tens of millions of models in operation.
Now the advantages and disadvantages:
| Advantages | Flaws |
|---|---|
| Reliable in operation | Low accuracy class – 2.0 |
| Huge operational resource, proven over several decades | Current and voltage consumption for own needs |
| As the load on the network decreases, the error in the indicators increases | |
| Does not respond to power surges | Big sizes |
| Possibility of electricity theft | |
| Acceptable price | When metering active and reactive electricity, two meters must be installed |
| Current consumption is taken into account only in one direction |
Electronic electricity meter
The operating principle of this type of device is based on converting an analog signal to a digital one. The resulting code enters the microcontroller, where it is decrypted and sent to the display in the form of readings.
Now about the advantages and disadvantages:
| pros | Minuses |
|---|---|
| Accuracy class – 1.0 and higher | High price compared to induction models |
| Several tariffs - from two and above | |
| When metering different energies, one meter is used | |
| Accounting and control is carried out in two directions | |
| Not only the amount of power is controlled, but also its quality | Cannot be repaired |
| Data is stored for a long time with easy access to it | |
| Recording unauthorized electricity consumption | |
| Readings can be taken remotely, taking into account the use of various communication networks | |
| Possibility of using automatic accounting programs | High sensitivity to the quality of supplied power |
| The interval between checks is long | |
| Small sizes |
Which electric meter is better to install in an apartment out of the two indicated? How critical are the advantages of one and the disadvantages of the other? Here you need to understand that accuracy class “2.0” is normal for everyday use. Because it means that the actual electricity consumed may differ from the readings by only 2%. More accurate instruments are best used in industrial enterprises, where electricity consumption is huge, which means the error may be more significant.
Types of electricity meters by number of phases
There are two groups: single- and three-phase. Before choosing an electric meter for your apartment from these two, you need to look at the distribution board. If two wires enter the apartment, then it is provided with one phase. Therefore, the choice is clear – a single-phase electricity meter. If four, then there are three phases and a neutral wire. Accordingly, a three-phase model is installed in the shield. But most often apartments are provided with single-phase networks. Three-phase electricity meters are often installed in private houses with a large number of rooms and floors.
Attention! Apartments with single-phase power supply are provided with a voltage of 220 V. In three phases - 380 V. In the latter case, the phases are scattered over areas so that they form loops with a voltage of 220 V. For example, in a three-story building, the phases are distributed separately to each floor.
Selection of electricity meters according to tariffs
First of all, you need to understand what tariffs mean and why they are different. The bottom photo shows how electricity consumption changes during the day. It clearly shows that the main peak occurs in the morning and evening, when the whole family gathers in the apartments. But at night, consumption drops sharply because everyone is sleeping. Therefore, energy supply organizations have established two tariffs:
- from 7.00 to 23.00 – increased;
- from 23.00 to 7.00 – reduced.
| Cable cross-section, mm² | Copper wire | Aluminum wire | ||||
|---|---|---|---|---|---|---|
| Current strength, A | power, kWt | Current strength, A | power, kWt | |||
| 220 V | 380B | 220 V | 380B | |||
| 1 | 14 | 3 | 5,3 | - | - | - |
| 2 | 19 | 4,1 | 7,2 | 14 | 3 | 5,3 |
| 4 | 27 | 5,9 | 10 | 21 | 4,6 | 7,9 |
| 6 | 34 | 7,4 | 12 | 26 | 5,7 | 9,8 |
| 16 | 80 | 17 | 30 | 55 | 12 | 20 |
| 25 | 100 | 22 | 38 | 65 | 14 | 24 |
Attention! The table shows the parameters of electrical networks constructed according to the type of hidden wiring.
In modern apartments, a copper cable with a cross-section of no more than 6 mm² is usually installed. This means, according to the table, it will withstand a network current of 34 A. In old houses, an aluminum cable with a cross-section of no more than 4 mm² was laid.
Pay attention again to the table, which shows the dependence of current on power consumption. The last parameter is the total power of all household appliances and lighting. The power of devices is determined by the passport or on a metal tag (nameplate). There is a power formula in which the relationship with current strength is direct:
P = U × I , Where
- U – mains voltage (220 or 380),
- I – current strength.
I=P/U
The main thing here is to take into account the power of all devices.
Government Decree No. 442 of May 4, 2012 “On the replacement of electricity meters”
What provisions do you need to know in order to avoid getting into situations the result of which could be disastrous for apartment owners? The regulation itself regulates the energy consumption market. It clearly states the responsibilities of the electricity supplier and consumers. But for the latter, the main point is to replace old devices with new electronic ones. And that's the problem. Why?
The resolution states that replacement must be carried out at the expense of the apartment owner. But here a contradiction arises. The energy supply organizations themselves are needed; they are paid money for the kilowatts supplied. Therefore, apartment and house owners are in no hurry to make replacements. In addition, if you decide to install a new device, then you should not purchase it with a high accuracy class, because the latter is expensive. Why overpay for something you don’t need yourself.
Service life of an electric meter in an apartment
Many consumers confuse two concepts:
- The service life is full, it is indicated by the manufacturer in the passport as a warranty period. It differs greatly for different devices. For example, for induction ones up to 50 years, for electronic ones 25÷30. You can consider these numbers as the deadline for replacing electricity meters in the apartment. As an addition, a serious breakdown that will be more expensive to fix than buying a new device.
- Inter-inspection service life. This indicator is also indicated in the meter’s passport. It indicates when the device has been tested to meet the stated parameters. The first test is carried out by the manufacturer himself in his own laboratory. He indicates the date of the check in the passport.
So, Resolution No. 442 establishes the terms of inter-inspection operation. Induction single-phase electric meters must be tested once every two years, three-phase ones once a year. As for electronic models, they can be checked once every 4–16 years. The indicated fork is so large only because it talks about two different checks.
- Metrological testing is carried out once every 16 years.
- Check the reliability of the internal structure once every 6 years.
The last inspection is scheduled by the energy sales organization depending on the schedule of preventive maintenance. And it doesn't have to be 6 years. Prevention itself means removing the seal, removing the cover, cleaning the contacts, tightening the screws. After which the device is sealed again.
Attention! Starting from 2013, all electric meters with accuracy class 2.0 are not accepted for inspection and cannot be repaired. So if the verification period has come, then it is worth studying in advance how much a new electricity meter with an accuracy class of 1.0 costs.
How much does it cost to install an electric meter in an apartment?
Let's start with the fact that you cannot install the meter yourself if you are not an electrical specialist. Installation and connection must be carried out by an electrician authorized to carry out this type of work. It is not necessary to call a regular electrician for this. This may be a private entrepreneur or a representative of a private company. But after installation, the device must be sealed. Therefore, you will need to call a representative of the energy supply organization. He will install a seal and draw up an acceptance certificate.
