To account for electricity in everyday life, at industrial enterprises, as well as in energy companies, special devices are used. The Neva electric meter has a high level of reliability, developed taking into account the wishes of users. The meter is intended for installation in residential and public buildings, as well as in cottages, summer cottages, garages.
Description of the Neva counter
NEVA meters are classified as electromechanical and electronic. New models have the following qualities:
- accuracy of indicators;
- protection against theft of electricity;
- after installation, they turn on automatically;
- work takes place without human help;
- small dimensions.
Neva is an electricity meter that is used to measure and control active energy, both in single-phase and three-phase AC networks. Single-phase meters keep records in two-wire networks with a voltage of 220 V. Three-phase meters take into account three-phase alternating current in three and four-wire networks with a nominal frequency of 50 Hz.
A three-phase network is increasingly used, which makes it possible to directly connect powerful electrical appliances - electric boilers, heaters, electric stoves, asynchronous motors.
Specifications
Neva devices are equipped with an electromechanical reading device (EMOU) or have a liquid crystal display (LCD). Energy is recorded in kilowatt-hours. Models for single-phase and three-phase networks differ:
- on the device of the counting mechanism;
- the value of the base and maximum current;
- housing design and installation method.
The operating temperature varies for LCD devices from -20 ° to + 55 °, for EMOU from -40 ° to + 55 °. They are designed for atmospheric pressure of 630–800 mm Hg. at a relative humidity of not more than 90% under conditions of 30 ° C.
The devices differ in the degree of protection against ingress of dust and water. For devices with DIN rail mounting the degree of protection is IP40, for the others - IP51.
Electronic meters Neva have the following reliability characteristics:
- the average number of hours to failure is 160 thousand;
- the interval between verifications is 16 years;
- service life is calculated for 30 years;
- retention of data in memory for at least 10 years.
The devices have a certificate of safety and electromagnetic compatibility, comply with regulatory and technical documents. Prices are formed depending on the type and model of the meter, availability of goods, retail network, region and other conditions.
How to take readings
Reading an induction meter is easy. After installing the device, the initial data are indicated in the act. At the end of the month, you need to write down all the digits to the decimal point that are on the scoreboard. The difference between the numbers is the monthly electricity consumption. By multiplying the number of kilowatts by the tariff, the payment amount is obtained.
The energy sales subscriber service takes readings and automatically generates a receipt. The user only has to pay the bill. But to control the calculations, you can do it yourself. Pulse electronics are not wrong. They have different ways of protecting themselves. They cannot be slowed down, stopped, turned off or turned in the other direction.
The electronic device has a display that displays the number of kilowatts, date, operating time and other information. The data changes after a few seconds.To calculate the consumption for a separate tariff, you should take and write down the initial and final readings for each zone for the reporting month.
Due to the wide variety of electronic models, it is impossible to develop a single algorithm for taking readings. Each device comes with detailed instructions. Almost all devices of this kind store data from the previous reporting period in memory.
Varieties of counters
All models in this series have a modern design and are made of high quality, non-flammable materials. Devices for single-phase and three-phase networks have similar characteristics, differ in some nuances and method of attachment.
Electricity meter Neva 101 is a common and reliable model. The meter is recommended for household installation, designed for a single-phase circuit. Has protection against the effects of a magnet. Mounted with three bolts. Its dimensions and fasteners correspond to the parameters of induction devices, which simplifies installation in case of replacing an old device. Counter price from 928 rubles.
Neva 103 1SO – it is a single-phase, single-rate electricity meter. Suitable for use with moderate energy consumption - apartment, garage. Can be installed outdoors in a dry place. The meter body is not collapsible. Has an electromechanical drum dial. The pulse indicator flashes in proportion to the consumption. Install the device on a DIN rail. The cost is 984 rubles.
Neva 112 is a single-phase multi-tariff device. Allows you to keep records at four rates - day, night, half-peak, reserve. Suitable for apartments, as well as public buildings, businesses and other facilities. The data is recorded separately for each tariff plan. Information management is performed manually at the push of a button. The cost of the model is about 1300 rubles.
Neva 303 is a three-phase one-rate device. Used in 3 and 4 wire AC circuits. It has an electromechanical counting mechanism, phase-by-phase load control indicators, and a current sensor. The minimum price of the device is 2199 rubles.
The three-phase two-tariff meter Neva is used to measure and account for alternating current energy by time zones of the day - day, night, peak, half-peak. Readout device - LCD, accuracy class 1, degree of protection IP50. Electricity meter Neva MT 324 can be installed in enterprises, retail premises, apartments with high energy consumption. The cost of the device is from 2468 rubles.
Installing the appliance
For proper operation, it is not enough to choose a suitable device, it must be connected correctly. A single-phase device is connected to a break in the power line. In order not to have to de-energize the entire supply line, an input circuit breaker must be installed in front of the meter. It is advisable to install the machine after the counter. It will protect the meter and the outlet line if a malfunction occurs in the consumer circuit.
The wiring diagram is shown on the back of the device cover and in the attached instructions. Single-phase meter Neva has 4 terminals - input and output of the phase wire, input and output of the zero line.
The phase wires leaving the machine are stripped 1.5 cm from the insulation. They are connected to terminals 1 and 3. Lead-out conductors, respectively, to terminals 2 and 4.
For a three-phase device, there are two types of connection - direct or through a current transformer. When there is a small number of low-power consumers in the circuit, the meter can be connected to the break of the supply conductors.
Direct connection of such a meter requires a three-phase supply network. More terminals and wires are used. After the machine, the phase conductors are connected to terminals 2, 4, and 6. At the exit from the counter - to 1, 3, 5. Neutral input to terminal number 7, output to 8.
Single-phase consumers can also be connected to such a device. To do this, a single-pole circuit breaker must be installed on one of the phases. The second conductor is taken from the neutral grounding bus.If the currents of powerful consumers exceed the rated value of the meter, a transformer must be installed.
When a meter needs to be replaced, it is important to select the correct certified device for the network. You can connect a single-phase electric meter yourself. The three-phase device requires a permit. Before installation, you must read the instructions. When installing the device, you should strictly adhere to the sequence of actions and check the reliability of the connections.
