Electrical energy meter is a measuring device that allows you to take into account the consumption of electricity at industrial facilities or at home. It should be borne in mind that there are a large number of such devices. They differ from each other in some engineering features and indicators. Connecting an electric meter with your own hands 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 the metal components in motion. The rotation of these elements is fixed, but in numerical terms. Such a counter has an adequate cost. However, it is necessary to take into account the presence of a small error.
Electric appliances appeared much later. In this case, the unit is devoid of moving parts, and electricity is calculated using semiconductors.or microchips. Such a device provides accurate readings.
In addition, meters are divided by the number of supported phases. Moreover, this indicator for the device must match the properties of the network. There are single-phase and three-phase electricity meters.
Parameters
One of the main parameters of such a device is the accuracy of accounting for consumed electricity and the allowable error. The currently acceptable margin of error is 2 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 instrument is also based on its own voltage class. Most often it is equal to 220 W, 380 W or 100 W.
It is worth paying attention to the type of installation. For example, the location of the device on the high side requires a transformer. Thanks to the latter, the input voltage will not exceed 100 watts. If there is a transformer at the input, then the side is called "high".
Another important indicator is tariffs. In private homes, single-tariff devices are often used. Two-tariff meters have a higher cost, which is associated with the needregistration of permits. Therefore, they are used in industrial plants and office buildings. Multi-tariff devices make it possible to divide energy according to several directions, for example, day and night.
Accuracy class
The meter's accuracy class is one of the main characteristics of such a device. After all, the device is used for accounting and rational use of electricity. Accuracy class 1.0 is by far the most common. Often only electronic devices have this characteristic.
Release date
In fact, the date of inspection is more important than the date of release. All devices must be tested at the manufacturing plant before being delivered to the end user. 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 apparatus needs systematic monitoring of the measurement accuracy. It is recommended to produce after ten years from the date of manufacture.
Work order
First of all, you need to carefully study the rules for installing an electric meter. After all, this process is quite complex and responsible.
Firstly, the room where the installation is carried out must be dry. At the same time, it is allowed to install the unit on a wall, panels, in a cabinet, etc. In addition, in order to connect the electric meter with your own hands, you should purchase some equipment. In particular, a box for equipment, switches, a contact copper plate,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, it is necessary to completely remove the supply voltage and take measures that prevent accidental resumption of its supply. Then compactly distribute the meter, contact plates and other components in the shield.
At the same time, you need to leave room for further wiring. Then the wiring is done. Most often, the phase of the device comes out on the third contacts from the left. Such information can be specified in the instructions. Then they strip the wires and insert them into the desired terminal. Fastening here is carried out using bolts. Clamps are not required for circuit breaker.
Connecting a single-phase meter
Let's consider the connection of such a device using the example of a single-phase device. The Neva electric meter is used to record energy on a cumulative basis in single-phase AC circuits with a rated voltage of 230 V. It should be borne in mind that the device has an attractive appearance. At the same time, 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 the reliability of the connection of wires and terminals annually.
Installation should begin by placing the equipment in the shield. This is a prerequisite and protects the Neva electric meter from dust and water. Then the wiring is done. After that, you need to bring the phase of the counter to a separate machine by extracting several components from the cables. Attachment of the latter is carried out strictly vertically or horizontally.
After connecting the phase, output zero. Any wire will work for this. It must be cleaned and connected to the terminal. Then you should fix the shield with self-tapping screws. Next, you can proceed to the installation of grounding. Moreover, it is better to do this directly on the shield plate, if the latter does not conduct electric current.
Self-connection is possible only after the approval of the relevant authorities and further sealing of the device.
Connecting a three-phase meter
There are several options for connecting this device, such as indirect and direct. The first method is used when 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 forward flow and the reactive energy of the reverse direction of alternating current, the rated voltage of which is 400 V. This apparatus is equipped with an indicator made on the basis of liquid crystals. Hedisplays received data. The counter can be used both autonomously and in a special system. Automated application requires preliminary preparation. That is, it is necessary to pre-program the device. "Mercury 236" allows you to conduct tariff calculations depending on the time of day and store information for a long time. In addition, it reports various errors and stores the information in the data collection center.
The three-phase electricity meter "Mercury" is installed inside special shields, which are equipped with a platform and a three-screw mount. There are several ways to enable. The converter is used if the consumed load of all devices is greater than the nominal value of the current passing through the device. Let's consider this type of connection. This is a prerequisite for the operation of the Mercury electricity meter.
The converter has two windings. The primary is connected to the gap of the power cables of the power supply. The secondary winding, which consists of many turns of thin wire, is considered the main element. The meter diagram is shown below.
This procedure is quite complicated and requires certain skills. Therefore, it is better to contact a qualified specialist.
However, connecting an electric meter with your own hands is still possible. To do this, you need to connect the current transformer to the corresponding phase. In this case, the primary winding is connectedinto the break of the power cables of the phase. Do not forget about the neutral, which is connected to the neutral bus.
Installation of the meter in the apartment
Installation of electricity meters in the apartment should be carried out by specialists in accordance with regulatory documents.
There are some 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. At the same time, 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, appliances are installed directly in the apartment, while in older houses the meter is located on the site in a special container.
If you move the device to the apartment, you should find out where you can fix it. First you need to prepare a place under 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, it is necessary to de-energize the input circuit and connect the device to the input machine. At the same time, grounding is connected to the shield in order to protect the existing household appliances from a short circuit.
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 onfacade of the building, at a distance of no more than 1.7 meters. However, at temperatures below zero, the readings of the device are taken into account incorrectly. That is why it is recommended to place it in a heated room. In addition, the consumer must ensure free access for employees of specialized organizations.
Conclusion
Installing electricity meters with your own hands is a rather difficult task. However, with some skills and knowledge, it is quite real. Please be aware of the need to comply with safety regulations when working with such installations. In addition, it is necessary to check the operability of the device by applying voltage to it. If the result is positive, you should contact the energy supply organization to complete the necessary documents.
