How to connect a single-phase electric meter Mercury 201

Installing an electric energy meter in the house will help to keep accurate records of the resource consumed in the household and save finances by paying for electricity not at the default rate, but at real costs. To ensure the safety and reliable operation of the device, the correct connection diagram for the Mercury 201 meter must be selected.

Basic requirements for counters Mercury 201

When purchasing a meter, you need to take into account that from the date of release (it is he who is taken as the date of the initial verification) no more than a year has passed in the case of devices with two phases and a maximum of 2 years if a single-phase device is selected. The device must have a seal with an embossed date of release - it is necessary for warranty service.

The meter body must also have a holographic sticker confirming the authenticity of the product, and the stamp of the state auditor, indicating that the product meets the specified accuracy category.

Replacing the electricity meter

To replace the old device with "Mercury", the consumer of power supply services must send a request to the HOA branch of his city about the requirements for the meters (including the accuracy class). Having received this data, he buys a suitable device.

Before dismantling the old meter, you must once again contact the authority, having made an appointment with an inspector, whose task will be to certify the integrity of the seal. If the consumer removes the meter without this procedure, he may be charged with theft of electricity and a fine.

The inspector will look at the seal, draw up an act on the dismantling of the old appliance and set a tariff for the consumer based on data on electricity consumption for the last past months.

Before installing and connecting the meter, you will need to de-energize the power line if the switch is behind the device, or turn off the input circuit breaker.

Connection Mercury 201

There are 2 ways to connect a Mercury 201 meter, differing in its position relative to the machine from which electricity enters the network. Electrical installation rules prescribe that the meter must be connected after the machine. However, energy sales companies allow its use only if it is possible to seal the automatic device. If this procedure cannot be carried out, the meter is connected in front of the machine. Then the input wire will be connected to the device. To do this, you need to contact the HOA with a request to turn off the current on the line.

Sequence of actions for direct connection of the device:

• take it out of the box and unscrew the screws holding the terminal block panel;
• strip the insulating material at the ends of the connected wires by 1 cm;
• connect them to the required terminals and tighten the screws;
• plugs are dismantled in the panel - in their place there will be holes for wiring;
• put the panel in place;
• the inspector makes a sealing;
• power is supplied to the line - if the operations are performed correctly, a red diode on the front of the device will be on.

Products with three phases - Mercury 230 - are installed in the same way, if the total load power is not more than 60 kW. If it exceeds this figure, a modification of the circuit is used that includes a step-down transformer.

Connection diagram

You can find a connection diagram with other elements of the network in the instruction manual of the device or use the one found on the Internet. There are two types of instrument connections - direct and using a current transformer. The first option is used to connect any of the two types of devices (both single- and three-phase), the second - for a device with three phases at a load of 60 kW and above.

In the case of using a direct connection diagram of the Mercury 201 electric meter, the device is connected directly to the main transmission line. The semi-indirect circuit with transformers assumes that there are a large number of electrical appliances in the house that create very high voltages in the network. The current-transforming device used in this circuit uses a phase wire as the primary winding. A number of additional requirements are imposed on the installation of meters according to this scheme. The corresponding regulation can be obtained by contacting the HOA.

Connection diagram for four terminals with automatic devices

Here, the points are connected to each other in the following order (from left to right): first connect the phase wiring from the external network, then the phase to the load going to the apartment or private building. After that, neutrals are connected in the same way - first from the external network, then to the load cable.

Four checks by E.M. 201 for correct readings

After installing the meter, it is necessary to check the correctness of its connection and operation by carrying out a series of test measures aimed at fixing significant indicators of its functioning.

The first check is that the connection is correct

At this stage, a check is made with the scheme that the user was guided by when installing the product. Devices of the "Mercury" series are able to work correctly when changing the zero and phase locations, but the electrical safety rules require strict adherence to the installation sequence presented in the typical diagram.

The second check is for self-propelled

To carry out this verification stage, you will first need to create a situation of complete absence of electricity consumption in the apartment. To do this, it is necessary to cut down all automatic switches located below the electricity meter and supplying lighting devices and sockets. If there are no individual switches in the network, the cords of all household electrical appliances and extension cords are pulled out of the sockets, and the light switches are put in inactive mode.

A quarter of an hour after turning off all devices, it is necessary to evaluate the functioning of the electric meter - if it works validly, the roller on the counting mechanism should stop, and the light on the front of the device should not blink. The permissible maximum is a single blinking or counter revolution every 5-10 minutes.

If the rotation of the roller or blinking occurs, the test is considered to be failed. Then a laboratory check of the meter's functionality is required.

Third check - measurement error

Here, the metering error is calculated by the electricity meter. You will need to prepare a mobile phone with a stopwatch and a calculator (or these devices themselves separately), an electronic multimeter and an incandescent lamp as a loading device. It is not recommended to use household appliances, since the practical values ​​during the operation of the devices may differ from those indicated in the passports, creating additional errors, sometimes significant.

The sequence of actions when checking:

• Measure the voltage in the outlet with a multimeter.
• They put the device in the current measurement mode, connect it to the lamp, measure the value of the indicator.
• The real power and resistance of the lamp are calculated - for the first case, it is necessary to multiply the two indicators obtained above, for the second, divide the voltage by the current strength.
• Continuing to keep the lamp plugged in, count the time it takes for the roller to make 10 revolutions (with a stable voltage), and record this time in seconds.
• Record for calculations the constant of the device indicated on the front of the case.
• Find the actual consumption of electricity: square the power and then divide by the resistance.
• The figure from the previous calculation is multiplied by the number of seconds and divided by 3600 (the number of seconds in an hour) - the unit of measurement of the resulting value will be Watt-hour.
• 1000 is multiplied by the number of revolutions (in this case 10) and divided by the counter constant.

Now the actual error is considered. From the figure obtained in the penultimate paragraph, subtract the one found in the last one, divide this number by the last figure and multiply by 100. The result is expressed as a percentage (for example, -5%). A deviation of up to 10% in one direction or the other is considered acceptable.

The fourth check is for magnetization

This check is very simple: a thin sewing needle is brought up to the front of the machine. If it is attracted, it indicates magnetization. If, after a few days after dismantling the magnet, it does not dissolve on its own, you will need to purchase a demagnetizing device.

When installing meters "Mercury" operating on one or three phases, the correct connection in accordance with the established scheme is of decisive importance. After that, you will need to check the operation, the independence of the device and measure the error obtained during the operation of the electric meter.