The electric energy meter is a measuring device that allows you to take into account the consumption of electricity at industrial facilities or in domestic conditions. It is worth considering that there are a large number of such devices. They differ from each other in some engineering features and indicators. DIY connection of the meter is possible after studying all the features of the device.
Varieties
Electricity meters have several varieties. For example, mechanical is the most common. The principle of operation of such a device is quite simple: the current that passes through the device sets in motion metal components. The rotation of these elements is fixed, but already in numerical equivalent. Such a counter has an adequate cost. However, it is necessary to take into account the presence of a small error.
Much later appeared electrical appliances. In this case, the unit is deprived of moving parts, and electricity is calculated using semiconductors or microcircuits. Such a device provides accurate readings.
In addition, the counters are divided by the number of phases supported. Moreover, this indicator for the device should coincide with the network properties. There are single-phase and three-phase electric meters.
Parameters
One of the main parameters of such a device is the accuracy of accounting for the consumed electricity and the permissible error. At present, an acceptable margin of error is two percent. It is this indicator that is characteristic of most devices offered in the construction markets.
However, the options for connecting the device also vary. For example, this can be done directly or through a transformer. The choice of method depends on the load on the power grid. When this indicator is not more than 100 A, a direct connection is made. Otherwise, a transformer must be used.
The choice of device is also based on its own voltage class. Most often it is equal to 220 watts, 380 watts or 100 watts.
It is worth paying attention to the type of installation. For example, placing the device on the high side requires a transformer. Thanks to the latter, the input voltage will not exceed 100 watts. If a transformer is present at the input, the side is called “high”.
Another important indicator is the tariff. In private homes, single-rate devices are often used. Two-tariff meters have a higher cost, which is associated with the need to issue permits. Therefore, they are used in industrial enterprises and in office premises. Multi-tariff instruments make it possible to divide energy according to several directions, for example, day and night.
Accuracy class
Accuracy class of the counter is one of the main characteristics of such a device. After all, the device is used for metering and rational use of electricity. Accuracy class 1.0 is by far the most common. Often, only electronic devices have such a characteristic.
Release date
In fact, the validation date is more important than the release date. All devices must be tested at the factory before entering the final consumer. As a result of such an event, the device receives a mark in the relevant documents and a seal on the case. In addition, each device needs a systematic observation of the accuracy of measurements. It is recommended to produce after ten years from the date of manufacture.
Work order
First of all, it is necessary to carefully study the installation rules of the electric meter. After all, this process is quite complex and responsible.
Firstly, the room where the installation is carried out must be dry. In this case, it is allowed to install the unit on the wall, panels, in the cabinet, etc. In addition, in order to make the connection of the electric meter with your own hands, you need to purchase some equipment. In particular, a box for equipment, switches, a copper contact plate, a three-core cable and self-tapping screws.
Installation
First you need to decide on the choice of device. If you plan to connect the electric meter with your own hands, then preliminary preparation should be carried out. That is, you need to completely remove the supply voltage and take measures that will prevent the accidental resumption of its supply. Then you should compactly distribute the counter, contact plates and other components in the shield.
In this case, you need to leave room for further installation of wires. Then the wiring is carried out. Most often, the phase of the device goes to the third contacts on the left. You can clarify this information in the instructions. Then they strip the wires and insert them into the desired terminal. Mounting is carried out using bolts. Clips are not needed for the circuit breaker.
Single phase meter connection
Consider connecting a similar device using the example of a single-phase device. The Neva electric meter is used to record energy on an accrual basis in single-phase alternating current circuits with a nominal voltage of 230 V. It should be borne in mind that the device has an attractive appearance. Moreover, the components of the device are made of high-quality non-combustible material, which provides protection against increased input voltage and impulse noise. Such a meter is equipped with an LED indicator, which displays information about the characteristics of the connection. After the start of operation, it is recommended to check annually the reliability of the connection of wires and terminals.
Installation should begin with the placement of equipment in the shield. This is a prerequisite and protects the Neva electric meter from dust and water. Then the wiring is done. Then you need to bring the phase of the meter to a separate machine by extracting several components from the cables. Attaching the latter is carried out strictly vertically or horizontally.
After connecting the phase, zero should be output. Any wire is suitable for this. It must be cleaned and connected to the terminal. Then you should fix the shield using self-tapping screws. Next, you can begin to install grounding. Moreover, it is better to do this directly on the shield plate, if the latter does not conduct electric current.
Independent connection is possible only after the approval of the relevant authorities and further sealing of the device.
Three-phase meter connection
There are several connection options for this unit, such as indirect and direct. The first method is used if there is a converter or too much load on the network. The latter method is most often used in private homes.
As an example, we use a three-phase electricity meter "Mercury 236". It is used to calculate the active energy of the direct current and the reactive energy of the reverse direction of alternating current, the rated voltage of which is 400 V. A similar device is equipped with an indicator made on the basis of liquid crystals. It displays the received data. The counter can be used both autonomously and in a special system. Automated use requires prior preparation. That is, you must pre-program the device. "Mercury 236" allows you to conduct tariff calculation depending on the time of day and store information for a long time. In addition, it reports various errors and stores information in a data center.
The three-phase electricity meter "Mercury" is installed inside special panels that are equipped with a platform and a three-screw mount. There are several ways to enable it. The converter is used if the consumed load of all devices is greater than the nominal value of the current passing through the device. Consider just this type of connection. This is a prerequisite for the operation of the electricity meter "Mercury".
The converter has two windings. Primary connects to the gap of power supply cables. The secondary winding, which consists of many turns of thin wire, is considered the main element. The meter circuit is presented below.
This procedure is quite complicated and requires certain skills. Therefore, it is better to contact a qualified specialist.
However, connecting a power meter with your own hands is still possible. To do this, connect the current transformer with the corresponding phase. In this case, the primary winding is connected to the gap of the phase power cables. Do not forget about the grounding, which is connected to a neutral bus.
Installation of the counter in the apartment
Installation of electricity meters in the apartment should be carried out by specialists in accordance with regulatory documents.
There are several basic requirements. In particular, the device is placed in dry rooms with free access for work. The temperature in winter should not be below zero. Installation of the device in external boards is allowed. In this case, it is necessary to ensure their stationary insulation. In addition, the installation height of the device must be at least 0.4 m. The listed requirements are called "Electric Meter Installation Rules".
It is worth considering that in new buildings, devices are installed directly in the apartment, while in older houses the meter is located on the site in a special container.
In the case of transferring the device to the apartment, you should find out where you can fix it. First you need to prepare the place for the shield. The optimal value for the height of the structure will be 1.5 meters from the floor level.
However, the question arises: how to connect the electricity meter yourself? To do this, disconnect the input circuit and connect the device to the input circuit breaker. At the same time, grounding is applied to the shield in order to protect existing household appliances from short circuits.
Installation of the meter in the house
Installation of the device is carried out in accordance with the rules for the installation of electrical installations. Electric meters for the home are most often placed on the facade of the building, at a distance of no more than 1.7 meters. However, at temperatures below zero, the readings of the device are not taken into account correctly. That is why it is recommended to place it in a heated room. In addition, the consumer should provide free access for employees of specialized organizations.
Conclusion
Do-it-yourself installation of electric meters is a rather difficult task. However, in the presence of some skills and knowledge is quite real. Keep in mind the need to comply with safety rules when working with such installations. In addition, it is necessary to carry out a functional check by applying voltage to it. If the result is positive, you should contact the energy supplying organization to draw up the necessary documents.