Electronic electricity meter for electricity metering: the principle of operation and differences from induction meters

To measure the amount of energy on a section of the electrical network for a certain period of time is the main task of an electric meter. There are many metering devices - with revolving discs and modern electronic electricity meters. The home craftsman needs to know only one thing about such devices; you can't live without it. It is forbidden to interfere with the work or install it yourself.

Device and principle of operation

To account for DC electrical energy, constant-value devices are produced, which are used only at enterprises operating powerful equipment. They are produced in small batches and are not used for household purposes.

Sinusoidal harmonic form AC devices are produced for energy metering with a single-phase and three-phase voltage system.

The main elements that are located inside the body of the device include:

• terminal block;
• liquid crystal display panel (LCD);
• bodies for transferring information and managing work;
• instrument transformers;
• PCB with carbide elements;
• protective cover.

The internal algorithm for the operation of single-phase and three-phase devices is the same. Through transformer sensors signals are sent to the inputs of the microcircuit - converter. From the output of the microcircuit, the frequency signal goes to the input of the microcontroller. He adds up all the incoming pulses to get the amount of energy in kilowatt-hour.

The accumulated energy is recorded in the flash memory and displayed on the monitor. If the voltage in the network disappears, then information about the accumulated energy is stored in the memory. It is read by the microcontroller and then displayed on the indicator after the voltage is restored. The device continues counting from this value.

This algorithm requires less than one kilobyte of microcontroller memory. The display can be 6-8 digit 7-segment LCD and is controlled by the controller.

Characteristics of the electronic counter

The first electronic metering devices were created in the 70s in Europe. The prerequisite for their creation was the development of electronics and the implementation of more complex tasks than energy accounting.

The appearance of such devices in the 90s in Russia was stimulated by the rise in energy prices, the privatization and restructuring of the electric power industry, and the emergence of various owners. In such conditions, manufacturing plants began to master the production of electronic meters.

The advantages of electronic models are undeniable:

• under conditions of rapidly changing and low loads, a high accuracy class is maintained;
• the ability to work at different rates;
• different types of energy can be taken into account by one device, including in two directions;
• it is possible to measure indicators of power, quality and quantity of energy;
• long-term storage of accounting data and access to them is permissible;
• unauthorized access and cases of theft of electrical energy can be recorded;
• the ability to remotely take indicators using various interfaces;
• losses can be calculated;
• the likelihood of creating modern ASKUE (automated system for commercial metering of electrical energy).

The declared advantages include the protection of devices from traditional methods of theft of electrical energy and up to 16 years the period of the calibration interval.

Today, electronic devices are more expensive than induction electricity meters..

Reliability assurance and repair

The device must have a certain accuracy value. You can check it in special electrical laboratories, which have the right to check and seal meters. You can evaluate the operation of the device at home:

1. When the load is disconnected, the indicator light of the device should stop. If he continues his account, then the device is faulty and self-propelled. It is better to do this at night, when the network is minimally loaded, and all electrical appliances are turned off.
2. The appearance of a noticeable buzzing of the device is not considered a sign of malfunction, if the self-propeller is not detected at the same time.
3. Distortions in the readings of the device, detected when receiving an invoice for the consumed electrical energy. For example, the meter reading for June was 100 kW. In July, the whole family went on vacation for a month, turning off electrical appliances, and according to the account, the consumption of electrical energy was 60 kW. In this case, the presence of a self-propelled vehicle must be checked.

In the absence of a self-propelled vehicle, the indicator light should not show more than one pulse within 15 minutes. So, if pulses are detected in the absence of a load, this indicates a malfunction inside the meter, it must be returned for repair.

To hand over the device for repair, it is necessary to call a representative of the energy-saving company, receive an order to check the device or to replace it.

Determination of instrument indicators

According to the data of the electric meter, a number of necessary indicators can be established:

1. Energy consumption for a certain period of time. For this, the initial readings are subtracted from the final readings of the counter. Depending on the type of device, these calculated data can be multiplied by the transformation ratio of the transformer current.
2. The fact that at the moment any electrical appliances or lamps are included in the apartment's network. If the indicator light does not count, then everything is off.
3. The power of the included devices.
4. The current flowing through the meter.
5. Overload in the network or on the meter itself.

The advantage of electronic meters is also the fact that they are produced both for one tariff, and for several.

Choosing the best option

Russian companies produce devices similar to foreign companies. Their cost is much lower, and the quality is not inferior to European leaders. All electricity meters must comply with GOST R 52320-2005, which is confirmed by the passport of the device.

The risk of getting incorrect results on consumed energy arises when buying models from little-known manufacturers. If they fail, there may be a problem with their repair. While well-known companies have service centers.

You need to choose a device for apartments with an accuracy class of up to 2.0 and the current must be at least 50 A. From 10 to 16 years is the optimal calibration interval for the device.

In the technical documentation, a seal is put on the device, which confirms the check for accuracy and operability passed at the enterprise, the date of this check is indicated. When the device is sold, the seller records the initial readings of the device. A state seal is placed on the electricity meter, on which the year and quarter of the test is recorded.

Before buying an electronic meter from an energy-saving company, you need to clarify which models are approved for use. Some companies require the purchase of metering devices that can be connected to the AMR system. In this case, the readings of the device are sent to the energy supplier automatically..

The best accounting devices

The service life of the device and cost savings depend on the correct choice of an electronic meter. According to customer reviews, there are no doubts about such manufacturers of measuring electrical equipment:

1. Incotex. This is a Russian company that is part of a powerful holding and has been producing models under the Mercury brand for 15 years. In terms of sales, this company ranks first in Russia.
2. Typeit. The company is located in St. Petersburg, founded in 1999 and produces electric meters of the "Neva" model and other measuring devices.
3. Energomer. It is a young company registered in 2010 and is the largest manufacturer of electricity meters on the Russian market.

All devices from these manufacturers are appreciated by both consumers and professionals..

Mercury

Model Mercury 201.8 is a modern metering device with a 7-digit LCD. Its accuracy class for measuring active energy is 1.0, the voltage ranges from 220 V to 230 V, and the current strength is from 5 A to 80 A. These devices can operate at temperatures from -45 ºC to +75 ºC, with a maximum humidity of up to 90%.

The modular housing, current transducer and screw terminals are all features of the device. An additional element of the device is LED illumination, which is very convenient for reading indicators.

The service life of these models is 30 years, and between revisions it is 16 years. These devices are easy to install, compact and have a minimum weight. They have a high accuracy class, good safety factor and budget cost.

Neva

Convenient and beautiful digital device Neva M. T. 123 is in demand not only in houses and apartments, but also in salesrooms, offices and enterprises.

This device can measure:

• mains voltage frequency;
• active power;
• voltage and amperage.

All models are distinguished by their versatility, accuracy of measuring electrical energy, reliability, quality of materials from which they are made, and favorable price.

The operating voltage is 230 V, the rated current is 5 A, and the warranty period is 30 years.

Energomera

The energy meter CE102M S7 145-JV is a model with an accuracy class of 1.0, resistant to climatic, electromagnetic and mechanical influences.

Device characteristics:

• current strength - 5 (60) A;
• voltage - 220 (230) V;
• operating temperature - -45 ºС (+70 ºС);
• humidity - 98%.

Additional capabilities of the meter are: non-volatile memory, the presence of a shunt, communication interface, indication of information for a certain period of time. The device is compact, easy to use and easy to reprogram. It is possible to read information from the device without the presence of voltage, its memory is protected from attempts to make changes. This meter is widely used in rooms with a large number of electrical points.