How to put a single-phase meter. Connection diagrams of a three-phase electric meter, direct and indirect connection. Tools and consumables for installing the meter

The circuit of a single-phase meter is quite simple. In this article I will tell you how to connect a single-phase meter. I already wrote earlier how to choose the right. Now, after buying a meter, there is a new task - to connect a single-phase meter to the mains.

Single-phase meters for houses and apartments are made with direct connection, i.e. without additional step-down current transformers.

There is nothing complicated in connecting a single-phase meter, before installing the meter, carefully study the documentation, instructions, examples of connecting single-phase meter circuits, etc. To properly connect a single-phase meter, we, first of all, need a single-phase meter circuit, which can be found:

• documentation, which the electric meter is equipped with is a passport, instruction or form for the meter, which indicates all the characteristics, serial number, dates of issue and verification of the meter, and of course - the single-phase meter circuit itself;

• additionally, the set of documents for the counter may include manual, which will also indicate the circuit of a single-phase meter;

• without fail, on the back of the terminal cover any electricity meter, will be applied;

• and of course, a single-phase meter circuit can be found on the Internet.

Having studied the circuit of a single-phase meter "on paper", we turn directly to the electric meter itself.

A simple single-phase meter has 4 pins on the terminal block:

• terminal No. 1 - input of a phase from an external network (to a house or apartment)
• terminal No. 2 - phase output (inside the house or apartment)
• terminal number 3 - zero input from the external network (to the house or apartment)
• terminal number 4 - zero output (inside the house or apartment)

In the same sequence, we connect the wires to the contacts of our single-phase electric meter, not forgetting to turn off the machine, plugs or knife switch, which is installed in front of the single-phase electric meter, if you have an input cable (wire) immediately comes to the meter, in this case, it is necessary to turn off the line.

When replacing an old single-phase electricity meter, if you decide to replace it yourself or called a friend-neighbor-electrician, at least make a call to your network company, management company, HOA and find out what needs to be done to replace a single-phase meter. Main question - who will break the seal from the old counter.

If you break the seal from the old electricity meter, and install a new one, and only after that report it to the power grid, serious problems may arise. You can be accused of stealing electricity (the seal is broken) and impose a heavy fine.

Scheme of a single-phase meter with an introductory machine

Scheme of a single-phase meter, when an introductory machine is installed in front of the meter. This should be the case according to the PUE, but if the introductory machine cannot be sealed, the network organization will not allow such a meter connection scheme.

Scheme of a single-phase meter, when the introductory machine is installed after the meter. This option for connecting an electric meter is used if it is not possible to seal the introductory machine. The cable (wire) is connected directly to the electricity meter, the terminal cover is sealed and there is no possibility of electricity theft.

Thank you for your attention.

Typically, metering devices are installed by organizations providing certain services. In this case, this is a meter for electric energy and the power grid or ZhEKi. Nevertheless, self-installation of an electric meter is not forbidden. The only thing is that the specialist must check the work and seal the meter.

Thus, connecting an electric meter with your own hands in an apartment or a private house is a very real and feasible task. But this must be done correctly and taking into account all the requirements for installation. This will help to avoid many problems, including accidents at the substation or in the house, fire and, finally, defeat. electric shock. Yes, and an incorrectly connected meter will not be accepted for work.

How does it work and what does it count

First of all, what does he think? He thinks, more precisely, reads the power consumption, which is usually expressed in watts per hour(W/h). A watt is a unit of power, and an hour, of course, is a unit of time. It is for the spent watts that we pay. Please note - not for amps or volts, but for watts. How much does the same hundred-watt light bulb "eat"? She "eats" a hundred watts, that's why it's a hundred watts.

But the amount of payment for its use will depend on the time during which this light bulb was on. Thus, the tasks of the electric energy meter include calculating the power of electrical appliances operating at each moment of time and calculating the time during which this power was consumed. As a result, at the output we get the so-called kilowatts per hour kWh, for which we pay. Kilowatts - because we spend so much watts that it's easier to add the prefix "kilo" (similar to kilograms and grams), and not write extra three zeros.

How he does it

P = I x U

Almost all electric meters do this. Mechanical - using the principle of eddy currents, which is quite difficult for a layman to understand, electronic - using analog or digital processing of signals from current and voltage sensors. The data obtained accumulates over time and, say, in a week you can read on the indicator (mechanical or electronic - it doesn’t matter) the readings corresponding to the amount of energy consumed in W / h. or kWh.

What are the types

All currently existing metering devices for consumed electricity can be divided into three groups:

• Mechanical;
• Electronic-mechanical;
• Electronic.

A dozen or two years ago, all electricity meters were mechanical. The eddy currents created by the current flowing through a special bus twisted the metal disk. The disk itself was placed in a magnetic field, which was the higher, the higher the voltage. The usual mechanical counter counted the disk revolutions. These counters were very capricious (for example, they had to be installed strictly vertically), their accuracy directly depended on the quality and condition of the mechanical components of the counting mechanism and was not high. Such a counter could be easily "cheated" by creating a strong magnetic field near it (in other words, bringing a magnet to the disk).

Probably everyone knows the mechanical counter-this real sample of the old product is still working in garages and cottages

Later appeared electronic-mechanical devices. The first calculated the power electronic methods, but the counter had a mechanical one. The latter are completely electronic, having a microcontroller, memory and a display of one type or another. Today, conventional mechanical meters are almost universally replaced by electronic ones. Firstly, electronic ones are much more accurate, more durable and better protected from sabotage (deception). Secondly, a modern electronic electricity meter is able to independently transmit data to the service provider via a separate line. On the same line, you can control the device - switch the day / night tariff, turn off the consumer, for example, for non-payment, etc.

Electronic-mechanical (left) and electronic electricity meter

What you need to know before installation

If you decide to install an electric meter with your own hands, then you will have to pay attention to some features of the correct connection. Some conditions must be met in accordance with existing requirements, others will ensure the safety of operation.

Before starting the installation, ask the supplier which electric meter can be supplied and where it can be placed. In private homes, for example, many electrical networks require metering devices to be installed outside the building, and the supply from the supplier must be made with a solid cable and not have switching devices. Some people allow, say, an automatic machine to be placed in front of the meter, but demand that it be placed in an electrical panel next to the meter so that the whole thing can be sealed.

If the electrical panel is metal, it will require grounding, which means the manufacture of a ground loop. In general, there are many nuances, so be sure to clarify so as not to redo it. As for the type, you should not install an old mechanical counter - if it is in your region that they are still “in vogue”, then they will soon go out of it, and you will have to spend money on buying an electronic-mechanical or electronic one.

Next item. Any electric meter has its own verification period. The new meter has already been verified by the manufacturer, and the period until the next test begins to “click off” from the moment the device was purchased (according to the sales date stamp in the passport). So if your device has lain in the closet even completely new for five years, then before you install it, you will have to take it to the appropriate organization for verification. You will also have to believe the device, it is impossible to determine the date of the previous verification - there are no corresponding verifications on the case, there are no documents for the device. After checking, both the manufacturer and the testing organization seal the device and this seal must not be broken!

There is a separate hatch with a cover for installation and connection in the meter. You can install the device, make the necessary switching without damaging the main seal. But when the work is completed and the electricians accept it, they will seal this hatch and, perhaps, the entire electrical panel (if the device is outside and has additional switching facilities to which you are not allowed to access) will be sealed. Now you can only take readings from the device by direct observation and nothing more.

And the last remark. If your network is single-phase, then it will be enough for you to connect a single-phase meter. If three-phase, then you will have to buy a three-phase device. Is it possible to put a three-phase meter in a single-phase network? Theoretically possible. The device will properly count the electricity in one phase, the other two will simply be idle. Practically - the electricity supplier will not allow just in case. “Why, if it costs 3 times more?” For them, there are fewer misunderstandings - you can sleep better.

Electric meter installation

So, the meter is bought, all the nuances of installation in a particular place are clarified with the electricity supplier. Suppose you decide to put a single-phase meter on the street. Here you will need an electrical panel to protect against the weather and against vandals. Yes, you didn’t forget to ask the electricians at what height it is their organization that is allowed to hang the meter? Hang on the maximum allowed, since the electrical panel, especially plastic, is no protection against vandals and burglars.

Now the routine. Fix the meter in the switchboard together with the switching devices (if any). You climb the stairs and fix the shield on the wall in one way or another - with dowels, nails, bolts, shoot with a mounting gun, weld - it doesn’t matter, the main thing is that the fastening is strong, reliable and durable.

Here comes a dilemma: if the shield is plastic, then it will protect the meter only from bad weather. If iron, it must be grounded. Which option to choose is up to you. If you have a ready-made ground loop at your disposal or you are able to make it (in a private house this is not a problem and the issue is not considered in this article), then, of course, metal is better. The meter itself, after installing the shield, must hang vertically - this is stipulated in the relevant provisions and spelled out in the device's passport.

The metal shield (left) is stronger, but requires grounding, unlike its plastic counterpart.

If you install a meter in an apartment, then you can use an open electrical panel. On the same shield, switching and protection devices will fit perfectly - automatic machines, RCDs or ordinary "plugs". You will have access to them, since the electricians will only seal the meter.

How to connect an electricity meter correctly

The meter is installed, shielded, if necessary, grounded. It remains to do the wiring. You climb onto a ladder with a voltage indicator (in everyday life - a “screwdriver indicator”) and find out which input wire you have is zero and which is phase. You go to the electricians and ask to turn off the power supply to your country or country house, and at the same time you enlist their word of honor that they will not “turn on” the light without your permission. In this regard, almost all electricians adhere to clear rules, and if they said that they would not turn it on, they would not turn it on.

If you yourself turn off the light, say, on a house shield, be sure to put an observer, because all these signs like “Do not turn on, people are working!” for the majority of our population - is nonsense. Half of the people never read anything, but on the move they click all the switches in a row. The second half, such an impression, does not know how to read at all.

Again on the ladder. Check the absence of voltage at the input and you can work. Almost all electric meters are connected in the same way. They have input and output terminals. Voltage is supplied to the input terminals from the supplier's line (input), from the output you take energy for your own needs. The terminals of single-phase meters are usually arranged in the following order:

1. Input phase wire;
2. phase output;
3. Input neutral wire;
4. Zero output.

If you don’t put anything before the meter, then run the input cable directly into the meter terminals, and you can’t confuse phase and zero! If you put, for example, an automatic machine in front of the electric meter, then connect the cable to it, and connect the automatic machine with segments of a single-core wire of the appropriate section with the input of the meter. Now you are wiring after the electricity meter by connecting all kinds of protective devices, RCDs, fuses, etc. If there is nothing like that, just connect the cable going to your house to the electricity meter output terminals. For example, below is a connection diagram for a meter with a protection system installed both before and after the meter itself.

An example of how to connect an electric meter to a single-phase network

The input machine protects the line from short circuit and allows you to de-energize the meter and everything after it manually. Immediately behind the electric meter there is an RCD that protects the house network from leakage currents, and the house network itself is divided into three lines, each of which is protected from short circuits by its own machine. Pay attention to the fact that the ground wire (green) does not break anywhere and does not start anywhere - neither into the meter, nor to the machines. It serves to ensure the safety of using electrical appliances and nothing more.

How to connect a three-phase meter

The whole difference between a three-phase electric meter and a single-phase one is only that it has not two, but four inputs (three phases and zero) and, accordingly, four outputs:

• 1, 2 - Input / output phase A;
• 3, 4 - -//- B;
• 5.6 - -//- C;
• 7, 8 - Input / output zero.

The scheme of its inclusion, which, by the way, is also in the accompanying documentation, looks like this:

How to connect an electric meter to a three-phase network

Do-it-yourself electric meter repair

Unfortunately, the electric meter is not a device that everyone can fix with their own hands, like, say, an iron or a table lamp. First of all, its case is sealed and after opening the device, it will have to be carried in fact. However, it would have to be done anyway. Modern electronic and electronic-mechanical meters are quite complex (no simpler than a washing machine or even a mobile phone), so to repair it you need to have special knowledge of electronics in the scope of the institute. Therefore, to answer the question "How to fix an electric meter?" in volumes small article it is impossible, just as it is impossible to outline in three words a repair manual, for example, for a PC or a GLONASS satellite.

As for mechanical devices, then, in principle, if you are familiar with the mechanics and the basics of electrical engineering, you can try to repair it by assembling, say, one of two or simply cleaning and lubricating it, because it is mechanical and most often the cause of the problem is dust and moisture. But, it is worth repeating, if you open the case of the device, it will need to be rechecked in the appropriate organization. Without opening, you can only replace the burnt terminals with which the meter is connected, but even here you will have to invite a representative of the service provider (controller or electrician) who will remove his seal from the terminal cover, and after the repair is completed, put it in place, after checking the connection of all wires .

To account for the consumed electricity, special devices are used - electric meters. Connecting an electricity meter with your own hands is carried out according to certain rules.

The device and principle of operation of the electric meter

The principle of electricity metering is the same in devices different type, but according to their design, they are divided into induction and electronic.

Induction or electromechanical counter

Induction meters have an aluminum disk that is rotated by two coils:

• voltage, connected in parallel with the load and measuring the mains voltage;
• current connected in series with the load.

The greater the current or voltage, the faster the aluminum disk rotates, transmitting rotation through a worm gear to a mechanical digital display. To reduce the inertia of the disc rotation, a permanent magnet is located inside the device, which slows it down with its field.

Through various manipulations, such metering devices can be made to rotate in the opposite direction. Therefore, electricity supply companies are replacing them with new, electronic ones.

The device of an electronic meter

An electronic electricity meter converts the measured power into analog signal and later digital.

The main part of this device is a microcontroller that records the consumed electricity. It transmits a signal to a liquid crystal display or an electromechanical display, as well as to the ASKUE system (automated system for monitoring and metering electricity).

These meters have built-in reverse rotation protection and anti-magnetic seals.

Connection diagrams for electricity meters

Connecting the meter to the network depends on the number of phases and the measured current and voltage and does not depend on the design of these devices. Terminal blocks in these devices are sealed by power grid controllers.

Single-phase electricity meters

Connection of a single-phase meter is made through a sealed terminal block. When using current or voltage transformers, secondary windings of transformers are connected to it. There are four terminals on the terminal block:

• incoming phase wire;
• outgoing phase;
• incoming neutral wire;
• outgoing zero.

The following figure shows the connection diagram of the electricity meter.

How to connect a three-phase meter

These devices are structurally three single-phase meters in one housing.

In induction electricity meters there are three aluminum disks on the same axis, and in electronic meters there is a common board.

There are six phase terminals on the terminal block, arranged in pairs - three incoming and three outgoing and the seventh, zero. Similar to single-phase meters, they are switched on directly or through a transformer. Some models have two zero terminals. The connection diagram of a two-phase meter is a cropped version of a three-phase one.

The connection of a three-phase meter in a private house is made in agreement with the power supply organization.

Turning on electricity meters through transformers

If it is necessary to measure the power in networks, the current or voltage of which exceeds the allowable for the metering devices used, the meter is connected through current and voltage transformers.

The calculation of the consumed electricity is made by multiplying the meter readings by the transformation ratio.

How to properly install an electric meter

Installation and connection of electricity meters is carried out in accordance with chapter 1.5 of the PUE.

State verification period

When purchasing an electric meter and installing it, you should check the presence of a state verification seal and its date. This seal is located on the body of the device, in contrast to the seal of the power company, located on the terminal block.

The quarter is indicated in Roman numerals, and in Arabic, on the reverse side, the year of the state verification date. According to the PUE, the period between state verification and sealing of the meter at the installation site should be no more than a year for a 3-phase device and two for a single-phase one. Whether the device was in operation does not matter.

Electric meter installation

Despite the fact that the installation of such devices is allowed to be carried out at a height of 0.8-1.7 meters, most often it is done so that the display is at a level convenient for taking readings and checking the integrity of the seals.

The meter is installed vertically, with a maximum deviation of 1 °. This rule was established for induction meters, the accuracy of which depended on the position, but was not abolished with the advent of electronic devices, for which this does not matter.

If the induction counter is given a horizontal position, then it stops. Therefore, the fastening of such devices was sealed by inspectors of Energonadzor.

Primary requirements

The basic rules for installation and connection of metering devices are determined by p.p. 1.5.27-1.5.29 PUE.

According to these rules, the electric meter must be located in a place convenient for both homeowners and electric company inspectors. Most often it is installed in the corridor or at the front door. You should also take into account external conditions - temperature, humidity and others. In high-rise buildings of the Soviet construction, such devices were located in the shield at the entrance.

The devices are mounted on a rigid base, in an open or closed panel, in an electrical cabinet or directly on the wall.

How to connect an electricity meter in a private house on the street

The rules for installing an electric meter in a private house on the street do not differ from the rules for in-house installation. However, at low temperatures, the device may show incorrect data. Therefore, for outdoor installation, according to PUE 1.5.27, the shield must be insulated and heated.

In addition, not only the owners and inspectors, but also unauthorized persons will have access to the shield. Despite this, in some cases, power supply companies require the installation of the shield on the street. This makes it easier to control the integrity of the seals and take readings.

Multi-tariff electricity meters

Electricity consumption is uneven at different times of the day. Therefore, in order to reduce electricity consumption during peak hours, electricity companies offer the installation of two-tariff electricity meters.

These metering devices take into account the consumed energy with an increasing or decreasing factor. It depends on the time of day and the device settings. Specific values ​​vary from region to region.

Dual zone tariff:

• in the afternoon with a ratio of 1:1;
• at night, 23.00-7.00 the coefficient is lowered.

Tri-zone tariff:

• in the afternoon, 10.00-17.00 and 21.00-23.00 ratio 1:1;
• during peak hours, 7.00-10.00 and 17.00-23.00 the coefficient is increased;
• at night, during the hours of minimum load, 23.00-7.00, energy is the cheapest, with a reduction factor.

Such appliances help to reduce your energy bill, especially if you turn on powerful loads such as washing machines, dishwashers or boilers during the hours of the cheapest electricity.

Despite the fact that such devices and their programming are more expensive than single-zone ones, this is beneficial. The combination of electric heating and a two-tariff meter is especially effective.

Connecting the electric meter yourself is easy. It is important to comply with all the rules of the PUE, otherwise the inspector of the electric company will force the work to be redone, which will lead to additional costs and wasted time.

The right counter is the main assistant in saving. To do right choice when buying, the first thing to decide is single-phase or three-phase. But how do they differ, how is the installation and what are the pros and cons of each of them?

In a word - single-phase are suitable for a network with a voltage of 220V, and three-phase - at a voltage of 380V. The first of them - single-phase - are well known to everyone, as they are installed in apartments, office buildings and private garages. But three-phase ones, which were previously used in most cases at enterprises, are increasingly being used in private or country houses. The reason for this was the increase in the number of household electrical appliances that require more powerful power.

The solution was found in the electrification of houses with three-phase cable glands, and to measure the incoming energy, many models of three-phase meters equipped with useful functions were released. Let's deal with everything in order.

Electricity is metered in two-wire AC networks with a voltage of 220V. And three-phase - in networks of alternating three-phase current (3-wire and 4-wire) with a nominal frequency of 50 Hz.

Single-phase power is most often used for the electrification of the private sector, residential areas of cities, office and administrative premises, in which the power consumption is about 10 kW. Accordingly, in this case, electricity is also metered using single-phase meters, the big advantage of which is the simplicity of their design and installation, as well as ease of use (taking phases and readings).

But modern realities are such that over the past couple of decades, the number of electrical appliances and their power has increased significantly. For this reason, not only enterprises, but also residential premises - especially in the private sector - are connected to a three-phase power supply. But does this actually allow more power to be consumed? According to the technical conditions for connection, it turns out that the power supply from a three-phase and single-phase network is almost equal - 15 kW and 10-15 kW, respectively.

The main advantage lies in the ability to directly connect three-phase electrical appliances, such as heaters, electric boilers, asynchronous motors, powerful electric stoves. More precisely, there are two advantages at once. The first is that with a three-phase power supply, these devices operate with higher quality parameters, and the second is that there is no “phase imbalance” when simultaneous use several powerful electrical receivers, since it is always possible to connect electrical appliances to a phase free from drawdown through "skew".