The Mercury-230 meter is equipment that is designed to measure power and energy (reactive, active) in one / two directions in three-phase 3- or 4-wire alternating current systems (50 Hz) by means of measuring transformers. It has the ability to take into account tariffs for the zones of the day, losses, as well as transmit indications and information on energy consumption through digital interface channels.
Specifications
The Mercury-230 counter has the following technical characteristics:
- Overall dimensions - 258x170x74 mm.
- The mass of the device is 1.5 kg.
- The time interval between verification is 120 months.
- The mean time between failures is 150,000 hours.
- The average operational life is 30 years.
- Warranty period is 36 months.
Functionality
The three-phase meter "Mercury-230" stores, measures, records, outputs to the LCD and subsequent transmission via interfaces of electric energy (reactive, active) for each tariff separately and in total for time periods at all tariffs:
- From the moment the readings were dropped.
- 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 Options
The Mercury-230 counter is capable of monitoring at 4 tariffs for 4 types of days in 16 time zones of the day. Each month, this equipment is programmed in accordance with an individual tariff schedule. Within a day, the minimum tariff period is one minute.
Also in power transformers and power lines can take into account technical losses.
Parameter Measurement
Additionally, the Mercury-230 counter can measure such parameters in the network:
- The instantaneous values of reactive, active and apparent powers by the sum of phases and by each phase, indicating the direction of the apparent power vector.
- Network frequencies.
- Angles between phase voltages, effective voltages and phase current values.
- Energy and load power control with transfer to the high-impedance state of the pulse output when increasing the specified settings.
- Power factors for the sum of the phases and for each phase.
Commit logs
The following information remains in the logs:
- The time when the three-phase meter "Mercury-230" was turned on / off.
- Time to increase the established limits of power and energy.
- Tariff schedule correction time.
- Closing / opening time.
- The appearance / disappearance of phases 1,2,3.
Interface
The electricity meter "Mercury-230" can be presented with the following interface:
- PLC-I.
- IrDA.
- GSM
- CAN.
- RS-485.
LCD Information
The electric meter "Mercury-230" displays the following information on the LCD indicator:
- Current date and time.
- Network frequency.
- Power factor total for 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.
- The measured value of the total, reactive and active powers (the integration period is one second) is summarized in three phases and each with an indication of the quadrant in which the full power vector is located.
- The value of consumed reactive and active electricity is cumulative 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 meter is connected to the electric line. Installation is quite simple - you just 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 No. 1 - input “A”.
- Terminal number 2 - output "A".
- Terminal 3 - input “B”.
- Terminal number 4 - output "B".
- Terminal No. 5 - input “C”.
- Terminal 6 - output “C”.
- Terminal number 7 - input "zero".
- Terminal number 8 - output "zero".
During installation, all available 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 showed that the installed capacity of consumers of electric energy in this case should not exceed 60 kW. The amount of current flowing through the Mercury-230 Art meter will be 92 A for this volume of consumption.
If there is a standard set of household devices in the apartment or house — air conditioning, a washing machine, a TV and a refrigerator — such a connection scheme for the meter can justify itself. If among the consumers there will be a heating boiler, it is preferable to choose a different connection method.
Semi-indirect connection scheme
A similar connection option is used when the installed power consumption of electric energy is over 60 kW. In this scheme, current transformers are used, the feature of which is the moment that the primary winding is replaced by an electric wire.
As a result of the flow of current in the secondary winding along the conductor, according to the laws of induction, an electric voltage occurs . The indicator of this voltage is fixed by the meter. To calculate the amount of energy consumed, it is necessary to multiply the transformation coefficient by the meter reading.
You can connect the Mercury-230 AM counter in this way according to various schemes, in each of which current transformers will be used as a kind of source of information.
A ten-wire connection scheme is considered the most common. Its main advantage should be called the presence of galvanic isolation of the 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 is as follows:
- Terminal No. 1 - input “A”.
- Terminal number 2 - input end of the measuring winding "A".
- Terminal 3 - output “A”.
- Terminal number 4 - input "B".
- Terminal number 5 - input end of the measuring winding "B".
- Terminal 6 - output “B”.
- Terminal 7 - input “C”.
- Terminal number 8 - input end of the measuring winding "C".
- Terminal number 9 - output "C".
- Terminal number 10 - input phase "zero".
- Terminal No. 11 - phase "zero" on the load side.
When installing the metering device for connecting to the transformer circuit break, special terminals are used, designated L1 and L2.
Another option for connecting a meter using a semi-indirect circuit is to reduce current transformers in a star-like configuration. In this case, the installation of the meter is facilitated, since fewer wires are required for installation, this is achieved by complicating the internal circuit. Such changes in no way affect the accuracy and quality of the readings.
There is another connection option using current transformers - seven-wire. Today it is completely out of date, despite the fact that it can be found in real conditions. The main disadvantage is the lack of galvanic isolation of the measuring and technological circuits. This feature makes this circuit dangerous to maintain.
For metering devices operating using transformers, a special requirement is formulated in the regulatory documentation: between the meter and the electric wire, it is necessary to install a contact block or panel through which all the necessary connections are made.
If necessary, the secondary winding is bridged, and the reference meter is connected to the measurement system. The presence of pads greatly facilitates installation. Equipment can be removed and replaced with another without disconnecting the main power line.
The 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 connection schemes need additional attention. Sales organizations prefer to work with direct connect devices.
Counter "Mercury-230": indirect connection
A similar option for connecting a meter is not used in the domestic sphere. An indirect circuit is designed to account for electric energy on the tires of generating enterprises. These include nuclear, hydraulic and thermal power plants.
On the buses that depart from the generator, current transformers are installed. Data from the terminals of the transformers is fed to the meter, fixing the amount of generated electrical energy. The latter, through distribution devices, via transmission lines, enters consumers connected to the network.
Consumer Reviews
The Mercury-230 counter (price - from 3,000 rubles) is used in the small-motor and domestic sectors to account for the consumed amount of electric energy. This equipment is installed in rooms or closed cabinets, which provide additional protection against the adverse effects of environmental factors.
Consumers noted a number of positive aspects characteristic of this meter:
- Compact overall dimensions.
- Low own energy consumption.
- Removal of the sealing part to the outside.
Accounting and distribution of electrical energy are complex technical tasks. Installation of electrical wiring and installation of meters must be done according to certain strict rules.