Today, there are few rooms where there is electrical wiring, but there is no metering device for consumed electricity. And this is quite natural, because these devices help to significantly save on services provided by electricity suppliers. Since there are more electrical appliances in homes, connecting a 3-phase meter is the best option, especially for urban residents.
Content
- The main types of electricity meters
-
Three-phase meter
- Instrument options
- Connecting the device
The main types of electricity meters
Since it is necessary to install the device not only in order to save money, but also at the request of the law, its choice should be approached responsibly. So, today manufacturers offer the following types of metering devices:
- mechanical (induction) - fixes the consumption of electricity through the operation of the coils;
- electronic - readings are recorded by microcircuits.
People of the older generation are well acquainted with counters with a disk rotating behind the glass. This is a mechanical electric meter. The essence of his work is quite simple:
But time and technology do not stand still, so induction devices are gradually being replaced by electronic ones. Obviously, the cost of such an innovation will be higher, but this will not only not hit the buyer's wallet, but, on the contrary, will help to save a decent amount on more accurate energy metering, plus everything will allow you to calculate the night and day tariffs.
The instrument reads the readings by digitizing the incoming analog signal. The built-in microcontroller decodes the code that is displayed. The main disadvantage of such a device is its high sensitivity to voltage drops in the network.
Three-phase meter
Electricity meters are divided into one- and three-phase and are designed for a network with a voltage of 220 V and 380 V, respectively. As a rule, unidirectional metering is carried out in buildings with low power consumption (10 kW). All other things being equal, a three-phase device wins in the main - allows you to connect appliances such as electric heaters, induction and glass ceramic hobs.
A relative disadvantage of such a device is the mandatory receipt of permission to install it. Also, due to its rather large size, it is necessary to take care of where and how to connect a 3-phase meter. When choosing a device, you should be guided by the maximum indicators of the current strength, on which the method of its installation will depend.
The advantages of the electric meter are the built-in tariffication and power profile.
Instrument options
Such a device really allows you to save money, since almost all of its models are equipped with the function of day and night billing. Depending on your needs, you can choose an electric meter taking into account the place of operation - for domestic or industrial purposes. There are three types of 3-phase meters:
- direct connection (connected to the network);
- semi-indirect inclusion (connected using a transformer);
- indirect (only through voltage transformers).
The connection of a three-phase meter in a private house, as in a multi-storey one, takes place according to special schemes that exist for each of the listed types of devices.
Connecting the device
Before starting work, you should make sure that the installation plan is developed correctly, and that all the necessary seals are present on the electric meter. The direct connection device is easy to install, but it is worth carefully studying the instructions for it. The main feature of connecting the device is compliance with the color order of connecting wires.
Installation begins with the fact that the conductors must be freed from insulation, and then connected to the switch. The next step is to connect the phase. Work should start from the right edge of the device, introducing wiring from odd terminals. "Zero" is connected to the two extreme contacts. Three-pole circuit breakers must be installed after the device is connected.
If we talk about how to connect a three-phase semi-indirect meter, then it should be noted that before starting work it is necessary to install an isolation transformer. Experts use various connection schemes for this type of device, of which only three are often used:
- ten-wire, where the first three - phase A, with 4-6 - B, the next two - phase C, and the tenth - "zero" (neutral);
- use of a terminal box;
- "star" circuit - connection with ground, where unipolar outputs and a winding are combined into a common point, which is then connected to the neutral wire.
The connection diagram for a three-phase meter through current transformers is used not only in order to be able to use powerful electrical appliances. Its main task is to reduce primary currents and voltages to a safe value.
Indirect switching is intended for high voltage connections and is used for industrial purposes. This type of meters is never used in everyday life.
Three-phase metering devices have a number of significant advantages over single-phase models. Their main advantage is the simplicity of the device and installation.
