Meter "Mercury-230" is equipment that is designed to account for power and energy (reactive, active) in one / two directions in three-phase 3- or 4-wire systems of alternating current (50 Hz) by means of measuring transformers. It has the ability to account for tariffs by day zones, losses, as well as transmit readings and information about energy consumption via digital interface channels.
Specifications
Meter "Mercury-230" has the following technical characteristics:
- Dimensions - 258x170x74 mm.
- The weight of the device is 1.5 kg.
- The time interval between verifications is 120 months.
- MTBF - 150,000 hours.
- Average service life is 30 years.
- Warranty period - 36 months.
Functionality
The three-phase meter "Mercury-230" stores, measures, records, displays on the LCD and then transmits via electrical interfacesenergy (reactive, active) for each tariff separately and in total for periods of time for all tariffs:
- From the moment it was reset.
- At the beginning and for the current day.
- At the beginning and for the previous day.
- At the beginning and for the current month.
- At the beginning and for each of the previous 11 months.
- At the beginning and for the current year.
- At the beginning and for the previous year.
Accounting parameters
Meter "Mercury-230" is able to control 4 tariffs for 4 types of days in 16 time zones of the day. On a monthly basis, this equipment is programmed in accordance with an individual tariff schedule. Within a day, the minimum tariff validity interval is one minute.
Technical losses can also be taken into account in power transformers and power lines.
Measuring parameters
Additionally, the "Mercury-230" meter can measure the following parameters in the network:
- Instantaneous values of reactive, active and apparent power for the sum of the phases and for each phase, indicating the direction of the apparent power vector.
- Network frequencies.
- Angles between phase voltages, effective voltages and values of phase currents.
- Monitoring the energy and power of the load with switching to a high-impedance state of the pulse output when increasing the set settings.
- Power factors for sum of phases and for each phase.
Fix logs
The following information remains in the logs:
- Time when the three-phase meter "Mercury-230" was turned on/off.
- Time to increase the set power and energy limits.
- Tariff schedule correction time.
- Device closing/opening time.
- Time of appearance/disappearance of phases 1, 2, 3.
Interface
Electricity meter "Mercury-230" can be presented with the following interface:
- PLC-I.
- IrDA.
- GSM.
- CAN.
- RS-485.
Information on the LCD display
Electric meter "Mercury-230" displays the following information on the LCD:
- Current date and time.
- Network frequency.
- The total power factor for the three phases and for each of them.
- Current and phase voltage in each phase.
- Evening and morning maximum reactive and active power in the previous three months and in the current one.
- Measured value of apparent, reactive and active power (integration period is one second) in total for three phases and for each with an indication of the quadrant in which the apparent power vector resides.
- The value of the consumed reactive and active electricity in total for all tariffs and for each of them with a cumulative total. Measurement accuracy - up to hundredths of kvar/h and kW/h.
Direct connection
In this case, the counter is connectedto the electrical line. Installation is quite simple - you only need to connect the ends of the cable from the input and output sides.
In this case, it is important not to confuse the wiring:
- Terminal 1 - input "A".
- Terminal 2 – output “A”.
- Terminal 3 – input “B”.
- Terminal 4 - Output B.
- Terminal 5 – input “C”.
- Terminal 6 - output "C".
- Terminal 7 – zero input.
- Terminal 8 – zero output.
In the installation process, all existing restrictions must be taken into account. Direct connection, as a rule, is used in networks with a flowing current of not more than 100 A. Indirect calculations have shown that the installed power of electrical energy consumers in this case should not exceed 60 kW. The value of the current flowing through the counter "Mercury-230" Art will be equal to 92 A with this amount of consumption.
If there is a standard set of household appliances in an apartment or house - air conditioning, washing machine, TV and refrigerator - such a scheme for connecting a metering device can justify itself. If there is a heating boiler among the consumers, then it is preferable to choose another connection method.
Semi-indirect wiring diagram
This connection option is used when the installed power consumption of electrical energy is over 60 kW. In this circuit, current transformers are used, a feature of which is that the primary winding is replaced by an electric wire.
As a resultcurrent flow in the secondary winding through the conductor, according to the laws of induction, an electric voltage occurs. The indicator of this particular voltage is recorded by the meter. To calculate the amount of energy consumed, it is necessary to multiply the transformation ratio by the meter readings.
You can connect the "Mercury-230" AM meter in this way according to various schemes, in each of which current transformers will be used as a kind of information source.
The ten-wire connection scheme is considered the most common. Its main advantage should be called the presence of galvanic isolation of measuring and power circuits. The disadvantage of this connection option is the large number of wires used.
The sequence of connecting the meter and transformers looks like this:
- Terminal 1 - input "A".
- Terminal 2 – input of the end of the measuring winding “A”.
- Terminal 3 – output “A”.
- Terminal 4 – input “B”.
- Terminal 5 – input of the end of the measuring winding “B”.
- Terminal 6 – Output B.
- Terminal 7 – input “C”.
- Terminal No. 8 - input of the end of the measuring winding "C".
- Terminal 9 - output "C".
- Terminal 10 – phase zero input.
- Terminal 11 - phase zero on the load side.
When installing a meter for connecting to a break in the circuit of transformers, special terminals are used, designated L1 and L2.
Another option for connecting a meter usingsemi-indirect circuit - reduction of current transformers into a configuration resembling a star. In this case, the installation of the meter is facilitated, since the installation requires fewer wires, this is achieved by complicating the internal circuit. Such changes do not in any way affect the accuracy and quality of the readings.
There is another connection option using current transformers - seven-wire. Today it is completely outdated, despite the fact that it can be found in real conditions. The main disadvantage is the lack of galvanic isolation of measuring and technological circuits. This feature makes this scheme dangerous to maintain.
For metering devices operating with the use of transformers, a special requirement is formulated in the regulatory documentation: a terminal block or panel must be installed between the meter and the electric wire, through which all the necessary connections are made.
If necessary, the secondary winding is shunted, and the reference meter is connected to the measurement system. The presence of the block greatly facilitates installation. Equipment can be removed and replaced without interrupting the main power line.
Measuring transformers used in metering devices do not always have the specified parameters. After a certain time, they should be checked.
It is important to consider these details when taking readings. Semi-indirect wiring diagramsneed extra attention. Distributors prefer to work with direct plug-in devices.
Meter "Mercury-230": indirect connection
Such an option for connecting a meter is not used in the domestic sector. The indirect scheme is designed to account for electrical energy on the buses of generating enterprises. These include nuclear, hydraulic and thermal power plants.
Current transformers are installed on the buses that depart from the generator. Data from the terminals of the transformers are sent to the metering device, which records the volume of generated electrical energy. The latter, through distribution devices, through transmission lines, goes to consumers connected to the network.
Consumer Reviews
Meter "Mercury-230" (price - from 3,000 rubles) is used in the small-engine and domestic sectors to account for the amount of electrical energy consumed. This equipment is installed in rooms or closed cabinets, which provide additional protection from the adverse effects of environmental factors.
Consumers have noted a number of positive aspects characteristic of this meter:
- Compact overall dimensions.
- Little own power consumption.
- Removal of the sealing part to the outside.
Metering and distribution of electrical energy are complex technical tasks. Wiring and installation of meters must be carried out according to certain strict rules.
