How does a two-tariff electricity meter work and is it profitable?

Advantages of a two-tariff meter

Two-rate meters have many advantages to consider. Depending on the model, these advantages may appear less or more, but still relevant:

• savings - thanks to the proper organization of life, they can save a lot of money, it is enough to load the washing machine and dishwasher at night;
• emission reduction - if the operation of the device is evenly distributed, emissions to the environment are reduced;
• assistance for electrical substations - saving money that can be used for other family needs is a distinct advantage.

Two-tariff electricity meter

Calculation for Moscow

Initial data for Moscow:

• Electricity tariff night zone (from 23:00 to 07:00) - 1.15 rubles / kWh
• Electricity tariff day zone (from 7:00 to 23:00) - 4.34 rubles / kWh
• Consumption during the day - 200 kW / month (all electrical appliances that cannot be transferred to work at night)
• Consumption at night - 100 kW / month (heaters, boiler, washing machine, partially refrigerator, dishwasher, etc.)
• The total consumption remained the same - 300 kW / month (all electrical appliances)

It turns out: 100 kW / month * 1.15 rubles / kW * h + 200 kW / month * 4.34 rubles / kW * h \u003d 983 rubles / month

Calculation for Novosibirsk

Initial data for Novosibirsk:

• Electricity tariff night zone (from 23:00 to 07:00) - 1.91 rubles / kWh
• Electricity tariff day zone (from 7:00 to 23:00) - 2.78 rubles / kWh
• Consumption during the day - 200 kW / month (all electrical appliances that cannot be transferred to work at night)
• Consumption at night - 100 kW / month (heaters, boiler, washing machine, partially refrigerator, dishwasher, etc.)
• Total consumption remained the same - 300 kW/month (all electrical appliances)

It turns out: 100 kW / month * 1.91 rubles / kWh + 200 kW / month * 2.78 rubles / kWh = 747 rubles / month

Why do electricity suppliers need multi-tariff meters?

Why would companies that produce and supply electricity need to reduce the cost of using it at night if it does not bring benefits? Here lie the pitfalls that consumers often stumble upon:

1. Stone first. With a two-tariff payment for electricity consumption during the day, you pay more. This is unprofitable, even if the difference between overnight and single-rate pay is large: at night, the average resident of Russia sleeps;
2. Second stone. In order to save on two-tariff electricity bills, you will have to change the way you use electricity. You should spend the main part at night and as little as possible during the day. And with a multi-tariff plan, you need to use electricity even less during peak hours. It is not comfortable. If you spend energy in the usual mode, the payment will increase, not decrease;
3. Third stone. Even if you change your lifestyle so that you spend most of your energy at night, your neighbors may remain unhappy. This is due to the fact that the dishwasher and washing machines are noisy: it will be difficult for neighbors to sleep;
4. Stone fourth. Purchase, installation, sealing and tariff setting are also financial costs. Therefore, even with a noticeable reduction in energy costs, spending may not pay off. Electricity providers can change the tariff plan, then you will again have to reconfigure the meter at your own expense. Then the counter can pay off for years.

An electricity supplier can be compared to playing poker online: players (electricity consumers) try to win (pay less for electricity), but if one side wins, the other loses (a two-tariff plan can either reduce or increase the total fee).But the poker room (electricity supplier) always remains in the black, if not by increasing the fee, then by smoothing out the peaks. Indeed, in order to supply the energy of the required power during peak hours, it is necessary to accumulate it in some way. Energy reserves are made in powerful and expensive batteries. The less they are needed, the lower the costs for the electricity supplier.

Payment for work on weekends and non-working holidays

According to Art. 153 of the Labor Code of the Russian Federation, work on a weekend or non-working holiday is paid at least twice:

• pieceworkers - at least at double piecework rates;

• employees whose work is paid at daily and hourly tariff rates - in the amount of at least double the daily or hourly tariff rate;

• employees receiving a salary (official salary) - in the amount of at least a single daily or hourly rate (part of the salary (official salary) per day or hour of work) in excess of the salary (official salary), if work on a weekend or non-working holiday was carried out within monthly norm of working hours, and in the amount of at least double the daily or hourly rate (part of the salary (official salary) per day or hour of work) in excess of the salary (official salary), if the work was performed in excess of the monthly norm of working hours.

At the same time, specific amounts of payment for work on a weekend or non-working holiday may be established by a collective agreement, a local regulatory act adopted taking into account the opinion of the representative body of workers, and an employment contract.

Recall that according to the Labor Code of the Russian Federation, wages (remuneration of an employee) consist of:

• from remuneration for work, depending on the qualifications of the employee, the complexity, quantity, quality and conditions of the work performed by him;

• from compensation payments (surcharges and allowances of a compensatory nature, including for work in conditions deviating from normal, special climatic conditions and in territories subjected to radioactive contamination, and other compensation payments);

• from incentive payments (additional payments and allowances of a stimulating nature, bonuses and other incentive payments).

Employees of Rostrud base their new clarifications on payment for work on a weekend or non-working holiday on Resolution of the Constitutional Court of the Russian Federation No. 26-P.

In paragraph 3.5 of the said decision, it is noted: Art. 153 of the Labor Code of the Russian Federation, considered in the system of current legal regulation, does not in itself imply that work on a weekend or non-working holiday performed by employees whose remuneration system, along with the tariff part, includes compensation and incentive payments, will be paid on the basis of only one component wages - salary (official salary), and these employees, when calculating the amount of payment for work performed by them on a weekend or holiday, may be arbitrarily deprived of the right to receive appropriate additional payments, which leads to an unacceptable decrease in the remuneration due to them compared to payment of a similar work performed on a normal working day.

Thus, when paying for work on a day off, the employer must take into account not only the tariff part of the salary, regional coefficients and percentage allowances, but also compensatory and incentive payments, as well as bonuses. This interpretation of Art. 153 of the Labor Code of the Russian Federation is given in the Resolution of the Constitutional Court of the Russian Federation No. 26-P.

In addition, Rostrud noted: despite the fact that the court decision refers to the civilian personnel of military units, it is indicated that the interpretation of Art. 153 of the Labor Code of the Russian Federation is mandatory, this conclusion of the Constitutional Court of the Russian Federation applies to all employers without exception.

How to accelerate the payback of such a device?

The payback of a two-tariff meter is a separate issue. For the installation or flashing of the device you need to pay a tidy sum. These devices are not installed free of charge and are more expensive than typical single-tariff flowmeters.

We talked about the cost of installing and replacing electricity meters in this material.

A two-tariff meter of any brand is more expensive than a single-tariff one due to the features of the software filling and more complex functionality

Externally, a two-tariff electric meter is no different from a standard meter. The difference between them lies only in the readings, which display information for night and daytime in different ways.

Due to the fact that the dimensions of the counters are the same, the new device can be installed in place of the old one.

Any person who understands electricity and fire safety can install a new two-tariff meter, but only an employee of the enterprise providing the service can seal the device

Before installation, you need to evaluate the feasibility of using the device and, perhaps, stop at a single-tariff device.

If the electric meter is already installed, you can think about the optimal consumption of electricity:

• turn on the washing machine and dishwasher only after 23:00;
• set a timer on the multicooker so that it starts cooking even before the household wakes up, i.e. until 7 am;
• start the water heating mode in the boiler (if any) only at night, and during the day activate the temperature maintenance function in it (much less electricity is required to maintain the water temperature than when it is heated).

In this case, it will be possible to achieve savings of about 200 rubles per month. Those. installation of an electric meter will be beaten off in 2 years.

If you don’t try to use electrical appliances after 23:00, then there will be no tangible benefit, because even the meter itself will beat off for about 5 years (if not more).

Popular Models

Today, three models of two-tariff meters are most in demand on the market - MZIP, Energomera and Mercury. Let's consider them in more detail.

Mercury

Mercury meters are manufactured by NPK Incotex, which produces a wide range of metering devices - from conventional 1-phase devices to more complex 3-phase models.

Products are manufactured at a high technical and scientific level, which makes NPK Incotex one of the best companies today.

Now the company also produces other products - KKM, ASKUE accounting and control systems, various types of screens and displays, POS and other equipment.

The popular multi-tariff meters include the following Mercury models:

• Three-phase - 256 ART, 234 ARM (2), 230 ART, 231 AT, 231 ART Sh.
• Single-phase - 206, 203.2T, 201.8 TLO, 200.

Energomera

Energomera positions itself as the leader of the Russian market for the production of metering devices. Every year, more than 3 million metering devices are produced on the territory of the enterprise's factories. At the same time, more than 30 million devices have been produced over 20 years of work.

The company includes 4 factories and 1 institute.In addition to two-tariff meters, the enterprise produces ASKUE systems, low-voltage equipment, metrological and switchboard equipment, devices for electrochemical protection and other equipment.

Popular models of multi-tariff meters include:

• Single-phase - CE 102-R5.1, CE 102M-R5, CE 102-S7, CE 102M-S7, CE 201-S7.
• Three-phase - CE 307-R33, CE 301-R33, CE 307-S31, CE 303-R33, CE 303-S31.

MZEP

At the moment, the Moscow plant MZEP is considered one of the best in the field of manufacturing metering devices. Every month, the plant produces more than 100,000 devices that are used both in private homes and in large organizations.

The company's products are certified and meet internationally accepted quality standards. Before being sold, the two-tariff meters of the plant are checked by the metrological service, and their compliance with the requirements is confirmed by certificates.

Popular multi-tariff models of the manufacturer:

• Single-phase - AGAT 2-12, AGAT 2-23M, AGAT 2-23M1, AGAT 2-27M, AGAT 2-42.
• Three-phase - AGATE 3-1.100.2, AGATE 3-1.5.2, AGATE 3-1.50.2, AGATE 3-3.100.5, AGAT 3-3.60.2.

Who benefits from installing a two-tariff meter

What is the reason for the appearance of such reviews? The main thing that should be known to those who are just planning to install a two-tariff electricity meter: people's reviews of the benefits and payback time of switching to such a metering scheme in different regions differ significantly due to the fact that the "day" and "night" tariffs set by energy companies in each region. So, for example, in the Russian capital and region, the price of a kilowatt for the urban population during the day is 5.57, at night - 1.43 rubles. Such a tangible difference makes the installation of a two-tariff meter incredibly profitable.

Another example: if a citizen lives in a rural area of ​​the Volgograd region, for him the day/night ratio for 2016 will be 2.81/2.01 rubles. In this case, the difference is not so felt. And given that during the day a citizen “overpays” for electricity relative to a one-tariff scheme, the benefit of installing a two-tariff meter is rather doubtful.

Therefore, before installing a two-tariff electricity meter, it is worth clarifying the difference between the day and night tariffs and deciding for yourself whether it is worth switching to such a metering scheme at all.

The principle of operation of a two-tariff meter

It is not difficult to understand how a two-tariff electricity meter works and what is the difference between a single-tariff and multi-tariff electricity meter. It records energy consumption in two periods: during the daytime from 7.00 to 23.00 and at night from 23.00 to 7.00. Such differentiated accounting by zones distinguishes a two-rate meter from a conventional single-rate meter, which records data around the clock at one rate.

The electrical energy consumed in private or multi-apartment buildings during the day varies greatly, which can be clearly seen on the load graph of an apartment building.

An example of a daily load schedule for an apartment building.

The graph shows that at night, from about 1.30 to 6.00, the amount of electricity consumed is the lowest. And the peak of loads falls in the evening from 18.00 to 22.00 hours.

Such a schedule can be a strong motivation to use electrical appliances at night.It is preferable to use household appliances with high energy consumption (washing machine, dishwasher, electric kettle, microwave oven, iron, air conditioner) at a lower peak load, and their use at night will save a lot.

When is a double energy tariff beneficial?

A two-zone energy tariff can be very beneficial. The cost of energy is 30% lower than for conventional, provided that the bulk of consumption occurs during the so-called off-peak hours. Such a tariff forces people to turn on the washing machine after 23.00, and companies organize work for the second shift. In any case, the savings are not immediately noticeable, it is difficult to immediately organize life in this way and adapt to the counter.

The choice of a two-zone tariff becomes cost-effective. Cost differences are per year and refer to the cheapest single and dual zone fares available in a given city. An annual consumption of 3,000 kWh for a home is the average for housekeeping. The consumption of more energy at the peak will make it unprofitable to choose a two-rate meter. The main thing is to always use the number of kilowatts within the monthly norm.

The location of the consumer also plays an important role. Although the profitability thresholds in individual cities are more uniform, the difference reaches 15%, which will still matter for the invoice amount. In a two-zone tariff, off-peak hours are from 13.00-15.00 and from 23.00-6.00. Most people work or sleep at this time, which makes it difficult to organize household processes.

But many household appliances, such as a washing machine or dishwasher, have a delayed start function.Therefore, you can perform the most energy-intensive actions at a lower cost by setting the correct switching mode. In a household, washing machines and dishwashers are responsible for about ¼ of the total energy consumption.

If we take this fact into account, the achievement of the profitability threshold will be much closer.

Economical two-tariff meters are not cheap. They are cost-effective if a lot of electricity is used and 30% of the total consumption is a significant amount. If you wash a lot and often, cook on an electric stove and use other electrical devices, buying a counter is beneficial. They are also convenient for users in regions with high electricity tariffs, then the meter is the main way to save resources.

Accuracy

In modern electronic models, the accuracy class starts from 2 units, and can also be more than 0.5.

On the device, this characteristic is indicated by a number. Information in the technical documentation of the device is also indicated.

It is important to know: the legislative act sets the minimum accuracy class limit for private consumers at a level not lower than "2".

With standard electricity consumption in an apartment or a private house, the purchase of an ultra-precise measuring device will simply be irrelevant. The increased cost of the device simply does not pay off over the period of operation. For enterprises with a lot of powerful equipment, this solution is recommended.

Settlement ratio: what are the rules for calculating?

First you need to find out the cost of one kilowatt of electricity per hour. And the numbers must be determined under different conditions:

• When using a one-part scheme.
• Daytime.
• Night time.

The order of calculation has its own sequence:

1. The difference between one-rate payment and night time is determined.
2. Next, we need the difference between the daytime and the one-rate type.
3. The result of the first action is divided by the numbers of the second.
4. We add one to the result of the third stage.
5. We divide the unit by the result of 4 actions.
6. Multiplying by a hundred of the number obtained from the previous action.

What about the actual relationship?

This indicator will help you find out how much is actually spent on energy both at night and during the day. To do this, you need to take readings every day for one month. This is done twice, at 7 am and 11 pm. After that, the penultimate result is subtracted from the last one. So it will turn out to determine the average consumption per night and day. It is better to write the data in the form of a table, then it will be more convenient.

The value for daily consumption on average is also easy to calculate by dividing by the number of days in a month the sum of all daily readings. The same goes for calculating the average level at night.

The actual relation also has its own formula.

• We take the average night result.
• We divide it by the sum of the day and night average.
• We multiply the number from the previous result by one hundred percent.

Read more: Fire safety training in the workplace

Is a multi-tariff meter beneficial for apartments and houses with electric stoves, and for the rural population?

Most new buildings in Moscow are equipped with electric stoves, so the electricity consumption in such apartments is much higher than in gasified houses. Because of this, the prices for tariffs are slightly lower. The table below shows tariff rates for apartments equipped with electric stoves and for houses in rural areas.

One-rate	3,89
two-tariff	Night zone T2 (23.00 — 7.00)	1,68
Daily zone T1 (7.00 — 23.00)	4,47
multi-tariff	Night zone T2 (23.00 — 7.00)	1,68
Semi-peak zone T3 (10.00 — 17.00, 21.00 — 23.00)	3,89
Peak zone T1 (7.00 — 10.00, 17.00 — 21.00)	5,06

We took average indicators of electricity consumption per month of about 500 kW - regular use of an electric stove, washing machine, boiler, microwave and electronics. The ratio of electricity consumption for multi-tariff and two-tariff ones is the same as above: 40/10/50 and 90/10, respectively. The cost of 500 kW will be as follows:

• Single-tariff: 500 * 3.89 = 1945 rubles.
• Two-tariff:

T1: 500*0.9*4.47 = 2011.5

T2: 500*0.1*1.68 = 84;

Total for T1 and T2 = 2095.5 rubles.

Multi-tariff:

T1: 500*0.4*5.06 = 1012

T2: 500*0.1*1.68 = 84

T3: 500*0.5*3.89 = 972.5;

Total for T1, T2 and T3 = 2068.5 rubles.

Here, as in the previous calculation, multi-tariff accounting is more profitable than two-tariff accounting, but more expensive than single-tariff accounting. To increase the “profitability” of the multi-tariff rate, it is necessary to reduce consumption during the day and increase consumption at night by at least 12%, which will lead to an amount of 1935.9 rubles for multi-tariff accounting. Thus, for the beneficial use of a multi-tariff meter, it is necessary to spend electricity in a percentage ratio of at least 40/22/38 for T1/T2/T3.

Of course, it is best to reduce electricity during peak hours. However, this is quite difficult in today's pace of life. If you consume an average of 500 kW per month and the loss of 100 rubles is not a matter of principle for you, then leave a single-tariff meter. If you have an active "night" life or an electric boiler with which you are going to heat the apartment in winter at night, then a multi-tariff meter will be very beneficial for you.

Installation and operation

To switch to a new tariff system, it is recommended to buy a device with the corresponding function.It is better to purchase a meter from a company that supplies electricity. If the purchase is made independently, it is necessary to give preference to a specialized store.

To obtain permission to replace the device, you must contact the supplier with the appropriate application. After receiving the decision, you can call a specialist to replace the device. The installation of the meter consists in setting up, adjusting, sealing the new device. The specialist makes the appropriate notes in the technical passport. At the final stage of installation, the consumer must receive instructions from the master manual, information on the timing of the device check and taking readings.

Taking readings

A novice user should know how take readings correctly from a two-tariff electricity meter. This will help you avoid overpayments and penalties. It is better to collect data in one period - the last day of the current month. By observing this regularity, the user will be able to control the consumption of light.

It is recommended to write down all readings of the consumed electricity in a notebook. Data is collected following the following guidelines:

• Indications for the period "day" are designated "T1", and for "night" - "T2".
• You need to fix the numbers that indicate kW.
• Numbers separated by a dot indicate fractions of kW. They are not fixed.

Data calculation

To independently calculate the amount payable for electricity, you will need to subtract the previous T1 data from the T1 readings for the current period. The result is multiplied by the cost of 1 kW at the "Day" tariff.

From the readings of "T2" for the current period, the previous readings of "T2" are subtracted. The result is multiplied by the cost of 1 kW at the Night tariff.If the receipt for electricity comes to each tariff separately, the readings are entered into the "night" and "day" receipt. When the light is paid for on one receipt, the amount of two tariffs is entered into it.

Some energy supply companies send invoices to their customers with details already filled in and a ready calculation. In this case, users need to enter meter readings for the current period into the form.

If the consumer of electricity is filling out the receipt, he must know the following:

• all fields specified in the form must be filled in;
• in the column with bank details, the account of the energy supply company, the MFI and the code are indicated (the data must be in the contract with the light supplier);
• in the column with the data of the payer, the full name and address of residence are indicated;
• in the table "Electricity" it is necessary to record the month for which the calculation is made, the value of the readings "T1", "T2".

The principle of the counter

The principle of a two-tariff meter is that at different times of the day it takes into account the price of electricity at different costs. The cost of a kilowatt at night is significantly different from the day rate

It is worth taking into account the dynamic rhythm of life in our country. Many return home late at night, so it is beneficial to do all household chores after work.

To optimize the distribution of electricity use throughout the day, a counter for two tariffs was invented. The way it works is simple:

• a two-phase electricity meter from 7:00 to 23:00 calculates the cost of a kilowatt in accordance with the usual tariff;
• at night comes the second or preferential rate.

That is, it is not the meter itself that saves electricity, but simply divides it into two types.

How does a two-tariff electricity meter work?

Rising prices for electricity supplies are growing, which makes the average man in the street look towards cost-effective electricity meters. Unlike old induction devices, new devices have a number of advantages: two or more tariff zones, a minimum accuracy class limit, synchronization of indicators, etc.

The principle of operation of a two-tariff electricity meter:

• tariff zones. The device is programmed, and two zones are distinguished - “day” and “night”. The first zone counts the number of kW used by the consumer in the period from 7-00 to 23-00. The tariff zone "night" takes into account the period between 23-00 at night and until 7-00 in the morning;
• Database. The basis of a modern meter is an industrial controller. Like a minicomputer, in its memory it stores the minute, hour and "daily archive" of kW used by the user;
• Radio module. Almost all new models are equipped with radio modules (GSM or 3G technology is used), and monthly meter readings are automatically transmitted to the accounting control authorities.

Additional options, such as the built-in "event log", allow you to analyze voltage consumption and redistribute the load when using electronic devices to obtain a favorable tariff for yourself.

What is a multi-tariff accounting system?

The amount of energy consumed depends on the time of day, which forces power engineers to divide the day into several zones:

• NIGHT. It starts at 23.00 and ends at 7.00 in the morning. Its peculiarity lies in the most favorable tariff.
• MORNING (PEAK). This zone starts at 7.00 and lasts until 9.00.After rest, people wake up and prepare to go to work. They include a lot of electrical appliances, which leads to a sharp increase in load. In addition, during this period, the working day begins in companies and enterprises.
• DAY (SEMI-PEAK). This period covers a larger range from 10.00 am to 5.00 pm. The "lion's" part of the people at work, so the load is approximately leveled. The largest consumption remains with companies, firms and organizations.
• EVENING (PEAK). In the period from 17.00 to 21.00, the second phase of the greatest load takes place, when people return from work and turn on different load sources, namely washing machines, electric kettles, air conditioners, PCs and other household appliances.
• EVENING (SELF-PEAK). This zone is limited to two hours from 21.00 to 23.00. The period is special with a gradual decrease in the load as people go to sleep.

A multi-tariff meter is a special device for electricity metering that controls each of the mentioned periods. Thanks to this mode, the network is unloaded during peak hours due to the transfer of part of the power to night time or weekends.

The use of differential accounting allows you to reduce costs, which is especially important for enterprises with a round-the-clock work cycle or with short breaks in the work of consumers.

The purchase of a multi-tariff meter is considered a profitable investment for manufacturers of various products. With this approach, it is possible to reduce the cost of goods and thereby increase profits.

For the effective use of such devices, it is important to understand the intricacies of the operation of such meters and determine the relevance of their use.As for apartments and houses, there are enough metering devices designed to work with two tariffs

As for apartments and houses, there are enough metering devices designed to work with two tariffs.

How to find out if it is profitable for you to take a meter with two tariffs?

To combine a comfortable life and a low payment for electricity, you do not need to adapt to the meter. It is enough to choose the device according to your needs. To understand whether it is profitable to install a two-tariff electric meter for you, you need to complete three steps:

1. Calculate at what ratio of night and day electricity consumption (when calculated according to two tariff plans) the payment will be equal to what is considered in one rate (at one tariff);
2. Calculate the average actual electricity consumption at night and during the day;
3. Compare the actual ratio of night to day flow with what was calculated in point 1.

If the actual ratio of night to day is less than the calculated one, then it is unprofitable to have an electric meter with two tariff plans. If they are equal, then it doesn’t matter what counting device you have. You will notice the benefit only when the actual ratio of night to day is greater than the calculated ratio.

Calculation ratio definition

To do this, you need to know how much 1 kWh of electricity costs:

• With a single-rate payment (OO);
• Night (NO);
• Afternoon (DO).

Calculation procedure:

1. Find the difference between OO and BUT;
2. Find the difference between DO and OO;
3. Divide the result of action 1 by the result of action 2;
4. Add 3 units to the result;
5. Divide one by the result of step 4;
6. Multiply the number after step 5 by 100.This will be the calculated ratio (RO) of nighttime energy consumption to daytime energy consumption, at which the payment for electricity at least does not increase when a two-tariff meter is installed.

This can be expressed in one formula, but it is complicated:

Example. OO - 3.6 rubles per 1 kWh, BUT - 1.8, and TO - 3.9 rubles. We find the difference between OO and BUT - this is 1.8. Then we find the difference between DO and OO - this is 0.3. Now we divide 1.8 by 0.3. We get 6. Add 1 - now we have 7. Divide 1 by 7 and get about 0.14. And multiplying by 100%, we get 14%. This means that your nightly energy consumption must be at least 14% of the total (day + night) so that installing a meter with two tariffs does not hit your pocket.

Determining the Actual Relationship

Now you need to find out how much electricity you actually spend at night and during the day. To do this, take readings twice every day for one month at exactly 7.00 and 23.00. Then, by subtracting the penultimate reading from the last, calculate how much you spend on average during the day and how much at night. It is convenient to record the data in a table, as in the figure below.

Average Daily Value (ADV) is the sum of all daily readings divided by the number of days in a month. The average night flow rate (AMNR) is the sum of all night readings, also divided by the number of days in a month.

The actual ratio (FR) is searched for by the formula:

An example from the table: SZDR = 7, and SZNR = 3. Then FD = 3/(3+7)*100% = 30%.

Comparison of the calculated ratio with the actual

And how do you know that single-phase two-tariff electric meters will benefit? It is necessary to compare the relations we have obtained: RO with FD. Three cases are possible:

• RO>FO. Your costs when installing an electricity meter with two tariffs will increase. You don't need this;
• RO=FO. The costs will remain the same. There is no point in reinstalling;
• RO<FO. The transition to two-tariff payment will bring economic benefits.

Example. We have RO equal to 14%, and FD - 30%. This is the third case, which says that a two-tariff electricity meter will help us save money when paying for electricity.