An electric meter is a device designed to accurately measure the amount of electricity consumed.
Types of electric counters
By type of connection, the following types of electric counters are distinguished:
- Direct connection devices - directly connected to the mains. They are used for individual accounting in individual apartments;
- devices for indirect switching-connected via special transformers for measuring current. They are designed to measure large currents. With their help it is convenient to account for the electricity of a multi-apartment building.
Depending on the measured values, the counters are divided into:
- Single - phase - used for measurement in AC networks, where the voltage is 220 V;
- three-phase - for a voltage of 380 V. These devices support and single-phase accounting.
By design, electrical meters are divided into:
- induction or electromechanical, which are suitable for apartments with low power consumption. They consist of conductive coils, the magnetic field of which affects the disk - the moving element. The consumed electricity is directly proportional to the number of revolutions of the disk. Counters have such drawbacks: they allow errors in accounting and are poorly protected from theft of electricity;
- Electronic - are like for apartments with high energy consumption and enterprises. In devices, alternating current affects electronic components. At the output, impulses are formed, their quantity is proportional to the measured electricity. The advantage of the device is the ability to account for energy at differentiated tariffs.
How to choose an electric counter?
When choosing an electric meter it is recommended to pay attention to the following points:
- Take into account what voltage is provided for the electrical network - it can be single-phase or three-phase.
- Check the conformity of the instrument parameters with the maximum current load provided for the room where the meter will be used. As a rule, in apartments without electric stoves, it is 16-25 Amperes, and with electric stoves - 40-63 Ampere.
- Check the availability and validity of the meter verification.
- Take into account the settlement system. So, if a two-rate settlement system is used, you can reduce the cost of using energy at night. This is possible when using an electronic meter.
- Cost of the counter. Induction devices are cheaper than electronic ones, but inferior to them in some properties.
Requirements for electricity meters
Electricity meters must meet the following requirements:
- Correspond to its basic technical parameter - the accuracy class, which determines the level of measurement error of the device.
- The installed meters must necessarily be tested at certain periods.
- In the room where the meter is installed, it is necessary to observe
the correct temperature regime - in winter the temperature should not fall below 0 ° C, and in summer it should exceed + 40 ° C. - If the meter is located in a place accessible to unauthorized persons (for example, on a staircase), it should be in a special lockable cabinet, in which there is a window at the level of the dial.
- If the meter is installed in a network with a voltage of up to 380 V, it must be possible to disconnect it using a fuse or switchgear installed at a distance of not more than 10 m from it. It should be possible to remove the voltage from all phases that are connected to the device.
The service life of the electric meter is at least 32 years. Therefore, acquiring the device, you must take into account all its characteristics, because it will serve you for a very long time.