Electricity meter connection. Connection diagrams for three-phase electric meters: options, methods

There are more and more electrical consumers in the modern world every year. World electricity consumption is growing every year. TO 2035 experts predict that global electricity consumption will increase by 45-50%. Naturally, it is necessary to take into account this resource on one scale or another; this is why electricity consumption meters were created. In today's article we will tell you how to connect an electric meter and analyze the basic circuits.

Forecast of growth in electricity consumption until 2035. Clickable.

Currently global electricity consumption is approximately 22,000 TWh (terawatt hour). It’s hard to even imagine such an amount of energy consumed, 1 TW is 10 9 kW.

Purpose of the electric meter. Types of electricity meters.

Electric meter- a special electrical (electronic) device that is designed to take into account the amount of electricity consumed by the consumer.

By voltage type:

1. single-phase;
2. three-phase.

Three-phase meters in turn There are direct connection and transformer. Transformer connection meters are mainly used in metering units industrial enterprises. In household networks, single-phase and three-phase direct connection devices are widely used.

By type of work electric meters are:

1. electronic (modern version);
2. induction (outdated version).

Counters by type of work. Clickable.

How to connect an electric meter. Detailed diagram.

Many people wonder - “How to connect an electric meter, is it difficult to do?!” Everyone will have their own answer to this question, today we will tell you about it, and you draw your own conclusions.

A single-phase meter is the most common metering device in household networks. Connecting a device of this type is quite simple. Let's figure it out Electricity meter connection diagram step by step:

Electric meter connection diagram. Clickable.

Step #1

The power cable from the electrical pole or from the substation comes to the input panel. Next, the power cable must be connected to the input circuit breaker. In modern networks the most widespread received double pole circuit breakers. Two-pole machine simultaneously “tears” phase (L) And zero worker (N) conductors.

We connect the phase and neutral conductor to the terminals of the circuit breaker, and the ground wire P.E. to the ground bus.

Good manners require that the input cable be connected to the upper terminals of the circuit breaker.

Step #2

From the lower terminals of the input circuit breaker, the phase conductor goes to terminal No. 1 of the meter, the neutral conductor goes to terminal No. 3 of the meter.

Step #3

From terminals No. 2 and No. 4 of the electric meter, the phase and neutral conductors, respectively, go to the second two-pole circuit breaker (to the upper terminals).

Step #4

Group circuit breakers are connected to the lower terminals of the second two-pole switch: for lighting, socket groups or other loads.
As you can see, there is nothing complicated about the connection. But there are main points that you should pay attention to when assembling a wiring diagram for an electricity meter.

Electric meter connection. Highlights.

Box for sealing the circuit breaker. Clickable.

1. The input circuit breaker must be located in a special (usually plastic) box, which will subsequently be sealed by the energy supply organization.
2. Due to the fact that the input machine and the terminals of the metering device will be sealed and you will not have access to them, you should immediately pay attention to the high-quality clamping of the conductors connected to these devices. After 5-7 minutes, after clamping the conductors, it is necessary to tighten them again (pulse them).
3. Care should be taken when choosing circuit breakers. The input circuit breaker must be selected one rating higher than the rating of the circuit breaker installed after the meter. This way you can achieve some kind of selectivity. When connecting group machines, you should also pay attention to the correct choice

How to connect an electric meter. Other scheme options.

In addition to the connection diagram for the electricity metering device given above, slightly different schemes can also be used. For example, schemes using single-pole circuit breakers, RCDs or differential circuit breakers. They are practically no different
according to the type of connection from the diagram on two-pole circuit breakers.

Electric meter connection diagram. Clickable.

The only thing attention should be paid, when using a single-pole input circuit breaker, the neutral conductor from the input cable must immediately go to terminal No. 2 of the metering device. The neutral conductor, which comes out from terminal No. 4 of the meter, goes to the neutral bus or to a two-pole automatic device.

When using a single-pole input circuit breaker, you cannot “break” the neutral conductor to the electric meter.

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The main purpose of the electric meter is to measure the level of electricity consumption. Typically, the installation of such equipment is carried out by specialized employees, but if you wish, you can handle the installation of the electric meter yourself. The main thing is to carefully prepare for the upcoming event and do everything in accordance with the instructions, because self-installation full responsibility for the actions performed and possible consequences will rest solely with you.

Depending on the mechanism of action, electricity meters are divided into electronic and induction. Induction equipment is gradually being forced out of the market, mainly on the initiative of the government - such meters are very easy to “deceive”.

Electronic electricity meters are characterized by higher accuracy, smaller dimensions and excellent versatility. For example, modern electricity meters support operation in multi-tariff mode. This advantage is relevant for regions where electricity tariffs vary depending on the time of day. Therefore, when choosing between induction and electronic equipment, preference should definitely be given to the latter.

Electricity meters are classified according to the rated current value and accuracy indicators (class). The lower the class number of your meter, the less deviation it will work with.

To determine the approximate current rating required, divide valid value active power provided by the network organization per consumer, per voltage of your network, i.e. 220V or 380V.

Typically, higher power is allocated for a three-phase connection, however, the use of single-phase networks in domestic conditions is more appropriate and preferable.

Difficulties with connecting the meter arise in situations in which the owner needs to power a building with a design current above 100 A. In such conditions, direct “insertion” of the meter is not feasible. To install metering equipment, you will need to additionally connect current transformers.

The use of any intermediate components leads to an increase in the error in metering electricity consumption, so the transformer circuit must be properly planned. This task must be solved by a qualified specialist.

When choosing a meter, pay attention to the age of installation of the seal and the integrity of this element.

The state verifier's seal is attached to the screws of the casing of the metering device. The meter seal for a single-phase electrical network must be no older than 1 year. In the case of meters for three-phase networks, the maximum permissible period increases to 2 years.

You can handle the installation of an electric meter yourself without any problems. However, before you decide to “uncover” the pliers, obtain the necessary permits and other documents. To do this, contact your local network provider office with a request to issue technical specifications for the work. There you can conclude the necessary agreement.

The mentioned documents list a number of requirements that the user must fulfill before connecting the building to the power grid. The documentation also clearly delineates the responsibility between the electricity supplier and its consumer.

In accordance with current legislation, the homeowner must install a meter within their consumption networks. The best place to install the meter is a heated distribution panel in the house. However, recently, regulatory organizations have required that accounting equipment be installed strictly outside the residential premises and be freely accessible to inspection organizations.

For example, a representative of the network company may require that you install an electric meter on the facade of your house or even on a nearby power pole. All these points are discussed individually. Apartment owners are usually required to place the equipment in question in a common panel on the site.

According to official statements, electricity suppliers are forcing owners to install meters on the street to ensure accessibility to the device for the purpose of taking readings and performing maintenance. According to unofficial data, suppliers are trying to prevent the possibility of unauthorized access to metering equipment in order to steal electricity.

Electric meter connection diagrams

It is not necessary for a home master to understand any complex wiring diagrams for accounting devices. Therefore, we bring to your attention the most popular and basic options for connecting an electric meter.

The simplest option is a single-phase connection. To install such a network, you will need no more than 6 electrical wires without taking into account the load. The working “zero”, phase and ground cables are connected to the device input. Similar cables are placed at the output of the metering device.

For greater convenience and safety, it is recommended to install a circuit breaker in front of the meter. This device will automatically turn off the power supply in the event of an emergency.

Energy sales services do not have a very favorable attitude towards the mentioned switches. To avoid unnecessary problems and disputes, the switch should be sealed using a special plastic box, a DIN rail and the seal itself. All these additional devices cost little, take up virtually no space, and are very easy to install, so take a little time and save yourself from unnecessary headaches.

The design of the accounting installation contains special terminal blocks, also known as buses. This device is a copper strip fixed using special dielectric clamps. The bar has several holes through which wires are connected using screw terminals. This connection option is suitable for situations where there is a need to connect several separate wires into a single whole.

Video - How to install a single-phase electric meter

There are a number of important requirements that you will have to strictly comply with when installing an electric meter. First, review the safety regulations that apply to any electrical equipment.

It is not recommended to install an electric meter at sub-zero temperatures. Electronics do not tolerate cold very well - under its influence, the accuracy of measurements decreases.

For most household models of electric meters, the minimum permissible temperature installation is +5 degrees. Therefore, if the metering device is installed outdoors, it is necessary to provide for the possibility of installing it in a special heated and hermetically sealed cabinet.

The mounting height of the unit is 80-170 cm above the ground. If you install the counter lower or higher, it will simply be inconvenient for you to take numerical readings from the screen.

Electric meter connection procedure

Self-installation of an electric meter is carried out in a few simple steps.

First step. Prepare the necessary equipment for installation, namely:

Second step. Find out how many phases (1 or 3) your electrical network has. Calculate the required number of circuit breakers.

Third step. Install the meter into the panel housing. To fix the product, use the fasteners included in the kit.

Fourth step. Install circuit breakers. These devices are fixed to the DIN rail. The rail is pre-attached to the support insulators using screws. The machine itself is fixed on the DIN rail using a spring-loaded latch.

Fifth step. Install the protective and ground bus on insulators inside the panel body or on a special DIN rail. Use nuts and mounting screws to secure the elements. Place the busbars at a distance to prevent cable short-circuits.

Start installation by connecting the load to the machines, then connect the machines to the electric meter and only then connect the meter directly.

Sixth step. Connect all loads. The phase will go to the lower terminals of the machines, connect the “zero” to the “zero” bus, run the grounding cable to the corresponding ground bus.

Seventh step. Connect the upper terminals of the circuit breakers with jumpers. You can buy ready-made jumpers at a specialized store.

Eighth step. Connect the meter to the load. To do this, connect the “phase” output (represented by the third terminal of the electric meter) to the upper terminals of the circuit breakers, and connect the “zero” output (the fourth terminal of the electric meter) to the corresponding zero bus.

Ninth step. Attach the electrical panel housing to a wall or other flat surface at the optimal height for you.

Tenth step. Find the neutral, phase and ground wires. In the absence of grounding, the work will be extremely simple: you check each core using the indicator pointer, and it itself indicates the phase. If there is grounding, its core is usually placed in green.

Eleventh step. Turn off the power at home.

Twelfth step. Connect the “phase” wire to the first terminal of the electric meter, and the “zero” wire to the third terminal.

At this point, the independent connection of the electric meter is considered complete. Check the device at idle and begin to gradually apply the load. After the preliminary check, contact the energy sales office with a request for additional checking and sealing of the meter.

Good luck!

Video - Installing an electric meter yourself

Good afternoon, dear readers of the site! This article describes the diagrams for connecting a three-phase electricity meter to the electrical network and provides installation tips. We recommend not only studying the provided electrical circuits, but also watching video lessons that describe electrical installation technology and other important nuances.

Preliminary stage

Connecting an electric meter (ES) is the final stage electrical installation work. Before installing a three-phase ES, you must first have a wiring diagram. The device must be checked for the presence of seals on the casing screws. These seals must indicate the year and quarter of the last inspection and the seal of the verifier.

When connecting wires to the clamps, it is better to make a reserve of 70-80 mm. In the future, such a measure will allow measuring power/current consumption and rewiring if the circuit was assembled incorrectly.

Each wire must be clamped in the terminal box with two screws (they are clearly visible in the photo below). The top screw is tightened first. Before tightening the lower one, you need to make sure that the upper wire is clamped by first tugging on it. If a stranded wire is used when connecting the meter, it must first be installed.

Direct (direct) inclusion

This is the simplest installation scheme. When directly switched on, the vehicle is connected to the network without instrument transformers (Figure 2). Most often, this installation method is used in household networks for electricity metering, where there are powerful installations with a rated current of 5 to 50 A, depending on the type of wiring (from 4 to 100 mm2). The operating voltage here is usually 380 V. When connecting the wire to a three-phase meter, the color order must be observed: 1st phase A must be on the wire yellow, phase B – on green, C – on red. The neutral wire N should be blue, and the ground wire PE should be yellow-green. For a safe one directly connected to the network, a switching device must be provided in front of each meter to remove voltage from all phases connected to the meter. ( , clause 7.1.64).

Figure 2 – Direct connection of the vehicle to the network

A brief video instruction for connecting a three-phase meter is shown in this video:

Electrical installation of three-phase model

Connection to a single-phase circuit

Before describing this diagram for connecting the meter to a 380 Volt network, it is necessary to give brief description differences between three-phase voltage and single-phase voltage. In both types, one neutral conductor N is used. The potential difference between each phase wire and zero is 220 V, and in the ratio of these phases to each other - 380 V. This difference is obtained due to the fact that the oscillations on each wire are shifted by 120 degrees (Figures 3 and 4).

Figure 3 – Voltage fluctuations

Figure 4 – Voltage distribution by phase

Single-phase voltage is used in private homes, in the country, as well as in garages. In such places, power consumption rarely exceeds 10 kW. This also allows you to use cheaper wires with a cross-section of 4 mm2 on the site, since the current consumption is limited to 40 A.

For powerful electrical receivers, it is recommended to use three-phase power supply to avoid exceeding the rated value. When installing the meter, it is recommended to check the load asymmetry with a current clamp. between phases of the lighting network of public buildings should, as a rule, be uniform; the difference in currents of the most and least loaded phases should not exceed 30% within one panel and 15% at the beginning of the supply lines. (clause 9.5)

The schematic diagram of connecting a three-phase meter to a single-phase network (OS) is not so common, since in such cases single-phase metering devices are used. In most cases, the circuit is similar to the direct connection circuit, but phases 2 and 3 are not connected (connection occurs per phase). In addition, after installation, problems with certification organizations may arise.

Also about possible problems The operation of three-phase electricity meters when connected to a two-wire network can be seen in this video:

Connecting the meter to a 220 Volt network

Connection via current transformers

The maximum current of an electricity meter is, as a rule, limited to 100 A, so it is impossible to use them in powerful electrical installations. In this case, the connection to the three-phase network is not direct, but through transformers. This also allows you to expand the measurement range of current and voltage meters. However, the main task of input transformers is to reduce primary currents and voltages to nominal values ​​for ES and protective relays.

Semi-indirect

When connecting the meter through a transformer, it is necessary to follow the order of connection of the beginning and end of the windings of the current transformer, both primary (L1, L2) and secondary (I1, I2). Similarly, you need to ensure that the voltage transformer is turned on correctly. The common point of the secondary windings of transformers must be grounded.

Purpose of current transformer contacts:

• L1 - phase (power) line input.
• I1 - input of the measuring winding.
• I2 - output of the measuring winding.

Figure 5 – Ten-wire connection diagram via CT

This type of connection of the electric meter to a 380 Volt network allows you to separate the current and voltage circuits, which increases electrical safety. The disadvantage of this electrical circuit for a three-phase meter connection is the large number of wires required to connect the ES.

Star

This type of connection of an electricity meter with grounding to a 380 V network requires fewer wires. Connection according to the star circuit is achieved by combining the I2 output of all CT windings into one common point and connecting to the neutral wire (Figure 6).

Figure 6 – Star connection of transformers

The disadvantage of this method of connecting an electric meter to a 380 Volt network is that the connection diagram is not clearly visible, which can complicate verification of inclusion for representatives of energy supply companies.

Indirect

This connection diagram for a three-phase meter is used for high-voltage connections. This type of indirect connection is used in most cases only at large enterprises and is given for informational purposes only (Figure 7).

Figure 7 - Indirect inclusion

In this case, not only current transformers are used, but also voltage transformers. For a three-phase connection, it is necessary to ground the common point of the current and voltage transformers. To minimize measurement error, if there is asymmetry of phase voltages, it is necessary that the neutral conductor of the network be connected to the neutral terminal of the meter.

Connecting a single-phase electric meter, from a technical point of view, is not difficult. Some skills and a minimum set of tools are enough. More importantly, the electric meter, like any other metering device, must meet certain requirements, otherwise the grid company inspector will refuse to register it. In addition, representatives of energy supply organizations have their own opinion about some technical specifications, different from the consumer's opinion. It is precisely these moments that are discussed in this article.

Requirements for electric meters

There are several mandatory requirements, without which the meter will not be registered.

1. Each meter must have a passport that records: a conclusion about the suitability of the device, the date of initial and subsequent verification, information about commissioning. The passport is stored for the entire period of operation of the device.
2. The device must be included in the State Register of Measuring Instruments and have certificates of type approval and conformity.
3. Have government certification seals on the casing fastening screws, and a seal from the energy supply organization on the clamping cover of the terminal block.
4. The age of state verification seals at the time of installation should be no more than 12 months for three-phase meters, and 24 for single-phase meters.
5. The accuracy class of a newly installed meter for metering electricity consumed by citizens must be no lower than 2.0 (RF PP No. 442, clause 138).
6. The placement rules are set out in the PES clauses 1. 5. 27. – 1. 5. 38. They do not contain any special requirements, except for the only one, ensuring free and convenient access.

If the listed rules are met, i.e., all the conditions stipulated by the legislation of the Russian Federation are met, then the refusal of the network company to put the electric meter into operation on the basis that the meter is of the wrong brand, model, manufacturer is illegal (RF PP No. 442, clause 148).

Connection diagram for a single-phase electric meter

It’s hard to make a mistake here; the connection diagram for each specific model is shown on the terminal block cover and in the passport.

Single-phase direct-connection electricity meters use a sequential connection scheme. From left to right. 1 – supply wire phase, 2 – load phase wire, 3 – supply wire neutral, 4 – load zero wire. Wires stripped of insulation (25-30 mm) are inserted into contact clamps and securely clamped with screws. That's actually the whole installation.

The power part of the circuit is typical, i.e. it is suitable for connecting any single-phase direct-connection electric meter, regardless of its brand, model and manufacturer. All you need to know before proceeding with installation is the purpose of each of the incoming conductors.

In theory, the color marking of the wires should serve as an indicator of wire ownership. Neutral (zero), wire insulation color blue, blue, blue with a white stripe. Zero protective (grounding), insulation color is yellow with 1-2 bright green stripes. Phase, insulation color: black, red, brown.

Even if the color of the wire insulation is different, I do not recommend relying on it 100%. In practice, color marking can only serve as a guide to determine the identity of the conductor. You can reliably verify the identity of the phase wire using a probe indicator. It is more difficult to distinguish between the neutral and ground wires. Depending on the circumstances, you can use one of the methods shown in.

Actually, connecting an electric meter to the power grid is not difficult. More often, questions arise related to network design and operational features. I will answer some of them.

Is it possible to connect an electric meter without an input switch?

In principle, the input switching device can be of any design. The only mandatory requirement is that it must be designed for a fairly high current, from 30-40 A.

In the PES paragraph 1. 5. 36. there is a direct answer, no, it is impossible. The purpose of the switching device (fuse, input circuit breaker, switch) in this case is precisely for the safe installation and replacement of the electric meter. Contrary to popular belief, the input switch does not have to be located in close proximity to the electric meter. It is quite possible that the input switching device will be located in the interfloor distribution board. This does not contradict the rules if the distance between the meter and the switch does not exceed 10 meters.

Is it possible to install an electric meter on the street?

If you strictly follow the PEU, then you can’t step 1. 5. 27. The threshold for the lower temperature is specified, not lower than 0°. Considering the harsh climate of our country, maintaining the required temperature, even in a closed box heated by an incandescent light bulb, is impossible in principle. Nevertheless, energy supply organizations considered this installation method the most acceptable. Time will show the correctness of this approach, but in any case we will wait for changes.

Does the electric meter need grounding?

No, it is not necessary, but if such a question arises, I very much suspect that there is an intention to use the contact clamp as the splitting point of the combined PEN conductor (TN-C system). Alternatively, connect the output neutral wire to the ground loop. I strongly advise you not to conduct such experiments. This won't end well. About the features various systems Read about grounding in one site.

If everything is clear with the power part, then the connection to the ASKUE metering system is different. Depending on the communication system, the device must have certain functions. ASKUE assumes the same type of technical accounting means, therefore, before buying a specific model, you need to know for sure how data is transferred in a specific, local system.

The difference between this circuit and similar ones is the absence of an input RCD. I think it is wrong to place this device at the entrance for all occasions. The only small plus from connecting a common RCD is a small saving of money, but the big minus is the impossibility of localizing the fault. The previous scheme brought to reality. 1 – input switch, 2 – N bus, 3 – PE bus, 4 – group circuit breakers and automatic circuit breakers.

Characteristics of electricity meters

Although it is dedicated to the choice of parameters, when talking about how to connect an electric meter one cannot help but touch upon this topic once again. This time, from the point of view of the efficiency of electricity metering. Believe me, this knowledge will help in case of lack of mutual understanding with representatives of regulatory authorities.

• Number of phases. In our case, one. Therefore, we will only talk about direct-on meters that read the total (absolute) power consumption.
• Established operating voltage range. Indicates the voltage limits within which the device operates with the stated accuracy. Sometimes this parameter is confused with the maximum voltage, i.e. power surges, dips, after exiting which the electric meter saves the previously recorded information. The lower limit voltage value is zero (no voltage), and the upper value is the highest value of the extended operating voltage range. Another parameter within which the device remains operational, but its measurement error does not correspond to the declared accuracy class.
• Rated and maximum current. In the passport, the rated (base) current is indicated first, and the maximum current value is indicated in brackets or with a hyphen. For example, so 5-60 or so 10 (100). If everything is clear with the maximum current, 60 A is more than enough for an apartment, and no one in their right mind would put more than 100 A on one phase, then the minimum value of the base current can cause problems when registering the device.

The sensitivity threshold (starting current) depends on the rated current. Thus, for a single-phase meter with an accuracy class of 2.0, the starting current should not exceed 0.46% of the rated current, and for an accuracy class of 1.0, the sensitivity threshold is even lower than 0.4%. In fact, this percentage varies slightly among different models. Network companies attach great importance to this seemingly insignificant difference.

Let me explain using the example of Mercury 230AM-01 and 230AM-02 devices. The first has a base current of 5 A, the second 10. Although both devices have the same accuracy class of 1.0, their sensitivity is different: 20 and 25 mA, respectively. From the point of view of the inspecting authorities, using the 230AM-02 device instead of the more sensitive 230AM-01, there is a hypothetical possibility of not taking into account about 10 kW per year. That’s right, there is some truth in these fabrications, but this is provided that the power of the constantly connected load during the year does not exceed 1.1 W.

• Accuracy class. Although, according to the law, the accuracy class cannot be lower than 2.0, this does not mean that meters with a lower accuracy class at the time of the adoption of Russian Government Decree No. 442 (05/04/2012) immediately became illegal. Paragraph 142 of the same document contains an explanation that the devices used at the time the Resolution entered into force can be used until the end of their service life.

If there is only one current circuit, then there is one circle on the stick of the graphic icon.

• Number of measuring elements in the current circuit. For normal operation of a single-phase electric meter, one coil (sensor) connected in series to the phase circuit is sufficient, but to prevent the known reception and phase transfer, modern electronic meters use two current measuring circuits, one in phase and one in zero. Readings are taken from the circuit where the current is greater.

It is not visible in the picture, but in fact the device shows the current strength in the circuit: the body of a connected but not working washing machine is a potential equalization system. The current strength may not be impressive, but there is no load as such. It’s just that this simple picture illustrates the fact that there are currents in the N and PE circuits and an incorrectly connected electric meter, with a measuring element in the zero circuit, will take them into account, even if there is no current in the phase current coil.

It would seem that to us honest consumers, it makes no difference whether the meter can take into account the current of the neutral conductor or not. After all, when turned on correctly, the current strength in both conductors is equal, but if you intentionally or unknowingly connect the neutral wire coming from the meter to a common neutral bus located in the interfloor distribution board, then the meter will count non-stop, taking into account the energy consumed by you, your neighbors and others God knows by whom.

An electric meter is a device for recording the amount of electricity consumed. Electric meters are used both in production and in everyday life.

Types and types of electricity meters

According to the type of load, meters are single-phase and three-phase. In the household electrical network, in most cases, single-phase meters are used, because all household consumers operate from a single-phase 220V network.

According to their design, meters are electromechanical (induction) and electronic. Recently, in production and in everyday life, old-style meters have been replaced with new electronic meters. When commissioning new electrical networks today, only modern electronic meters are used.

This is due to the fact that they are more reliable in operation, and electricity calculations are more accurate. In addition, the functionality of some new electronic meters allows you to remotely find out and transmit information about consumed kilowatt-hours.

Connection Tools

Sometimes situations happen when the meter breaks down and needs to be replaced. Also quite often, if desired, the old meter is replaced with a new, more modern one. If the electrical network is just being put into operation, then the first installation of the meter is carried out in accordance with all modern norms and rules.

Regardless of the reason for installing a new meter, for its installation it is necessary to use some tools, electrical measuring instruments and consumables:

• pliers, side cutters;
• assembly knife;
• insulation stripper;
• screwdrivers;
• indicator screwdriver;
• drill, hammer drill;
• hammer;
• pointer tester or digital multimeter;
• monolithic copper wire;
• dowels, screws.

General connection diagram for a single-phase meter

In order to connect the meter correctly, you need to know its connection diagram. It should be noted that the process of connecting all single-phase meters is absolutely the same.

• Firstly, the meter is connected directly to the power circuit, i.e. in series with the supplied supply voltage and electrical load. If we consider electrical diagram completely, then it looks like this: input (supply) voltage 220V – single-phase meter – output voltage 220V – circuit breaker – transition (connection) box – electrical consumers.
• Secondly, each single-phase meter has four special power terminals for connecting wires. If we count these terminals from left to right, then the first terminal is the incoming phase, the second terminal is the outgoing phase. The third terminal is the incoming zero, and the fourth is the outgoing zero. Those. A single-phase meter has two input and two output terminals.

In order not to confuse the purpose of each terminal when connecting, the connection diagram is usually indicated either on the meter itself or in its passport.

Installation and connection of the meter

For each individual apartment, the meter is usually installed in a common panel on the floor of an apartment building or in the apartment itself. Sometimes meters are installed on the street. This usually happens if it is a private house.

The meter installation option depends on several technical issues. If an old (or unusable) meter is being replaced, then dismantling and installation proceed as follows.

To dismantle the meter being replaced, first turn off the input voltage to the meter and unseal it. Then the terminal cover on the meter is removed. A tester, multimeter or screwdriver-indicator is used to check the absence of voltage on the meter, after which all four wires are disconnected one by one using a screwdriver. When the meter is freed from all wires, it is dismantled from its installation location.

Installation and connection of a new meter is carried out in the reverse order. First, the new meter is mounted in place of the old one, then four wires are connected to the power terminals of the meter. The terminal cover is closed and the meter is sealed. After this, voltage is applied, the electrical load in the form of household consumers is turned on, and the operation of the meter is visually determined.

If the meter needs to be connected in a new location (for example, somewhere in an apartment), then the installation process will be a little more complicated.

First you need to decide on the installation location of the meter. Usually the meter is installed near the entrance to the apartment. When a location has been selected, you need to select a shield for the meter. The shield is selected so that inside it, in addition to the meter itself, it is possible to additionally install automatic switches and residual current devices.

• So, in the place marked on the wall, holes are drilled with a drill or hammer drill for installing the shield. Dowels are driven into the holes with a hammer. Then the shield is screwed to the wall with screws.
• The next stage is the installation of the meter itself in the panel. Currently, for mounting meters, automatic machines, RCDs, etc. special metal DIN rails are used, on which all this must be fixed. Very often, electrical panels already have a DIN rail. After installing the meter, modular equipment (automatic machines, RCDs) is installed in the required quantity.
• The next step is wiring, i.e. All wires must be connected to the meter. First, two wires are connected to the second and fourth terminals, i.e. to the counter output. In order to connect the wires, the wire strands are stripped with a knife (or better yet, a special insulation stripper). Then the wires coming out of the meter are connected to a general circuit breaker, which supplies voltage to electrical consumers.
• After this, the wires are connected to the first and third terminals, i.e. to the counter input. To do this, part of the insulation is also removed from them. After the wires are connected, the terminal cover is closed and the meter is sealed.

Typically, installation, connection and sealing of the meter is carried out by the energy supply organization. If you carry out installation and connection yourself, then in order to avoid misunderstandings and fines, you must first contact representatives of this organization, who themselves will approve the correct procedure for work.