Typically, metering devices are installed by organizations providing certain services. In this case, it is a meter of electrical energy and electrical network or housing and utility services. Nevertheless, it is not forbidden to install an electric meter yourself. The only thing a specialist should check the work and seal the metering device.
Thus, connecting the electric meter with your own hands in an apartment or private house is a very real and feasible task. But it must be done correctly and taking into account all the requirements for installation. This will help avoid many problems, including accidents at a substation or in a house, a fire, and finally, an electric shock. Yes, and an incorrectly connected meter will not be accepted for work.
- 1 How it works and what it thinks
- 2 How he does it
- 3 What types are
- 4 What you need to know before installing
- 5 Electric meter installation
- 6 How to connect the electricity meter correctly
- 7 How to connect a three-phase meter
- 8 Do-it-yourself electric meter repair
How it works and what it thinks
First of all, what does he think? He thinks, more precisely,reads the power consumption, which is usually expressed in watts per hour (W / h) Watt is a unit of power, and an hour, of course, is time. It is for the spent watts we pay. Pay attention - not for amps or volts, but for watts. How many "eats" the same stowaty light bulb? "Eats" it is a hundred watts, which is one hundred watt.
But the value of the fee for its use will depend on the time during which this light is on. Thus, the tasks of the electric energy meter include the calculation of the power of the appliances working at each point in time and the calculation of the time during which this power was consumed. As a result, at the output we get the so-called kilowatts per hour kWh, for which we pay. Kilowatts - because we spend so much watt that it is easier to add the prefix "kilo" (by analogy with a kilogram and a gram), and not to write three extra zeros.
How he does it
Theoretically, it is easy to calculate the electrical power - it is enough to know the voltage and current:
P = I x U
Almost all electricity meters do that. Mechanical - with the help of the principle of eddy currents, which is rather difficult for a non-specialist to understand. electronic - using analog or digital processing of signals from current sensors and voltage. The resulting data is accumulated over time and, say, in a week you can read on the indicator (mechanical or electronic - it doesn’t matter) readings corresponding to the amount of energy consumed in W / h or kW / h.
What types are
All current metering devices for consumed electricity can be divided into three groups:
A dozen or so years ago all electricity meters were mechanical. The eddy currents created by the current flowing through the special bus twisted a metal disk. The disk itself was placed in a magnetic field, which was the higher, the higher the voltage. I counted the speed of the disk conventional mechanical counter. These meters were very capricious (they, for example, had to be installed strictly vertically), their accuracy depended directly on the quality and condition of the mechanical components of the counting mechanism and was low Such a counter could easily be “deceived” by creating a strong magnetic field near it (in other words, to bring the magnet to the disk).
The mechanical counter, perhaps, everyone knows — This real sample of the old product is still working in the garages and dachas.
Later appeared electronic and mechanical devices. The former counted the power using electronic methods, but the meter had a mechanical one. The second is completely electronic, having a microcontroller, a memory and a display of one type or another. Today, conventional mechanical meters are almost everywhere replaced by electronic ones. First, electronic is much more accurate, more durable and better protected from sabotage (deception). Secondly, a modern electronic electricity meter is able to independently transfer data to a service provider on a separate line. It is possible to control the device along the same line - switch the day / night tariff, disconnect the consumer, for example, for non-payment, etc.
Electromechanical (left) and electronic electricity metering device
What you need to know before installing
If you decide to install an electric meter with your own hands, then you will have to pay attention to some features of the correct connection. Some conditions must be fulfilled according to the existing requirements, others will ensure the safety of operation.
Before you begin the installation, ask the supplier what electricity meter can be put and where can it be placed. In private homes, for example, many power grids require the installation of metering devices outside the building, and supply from the supplier must be made of solid cable and not have switching devices. Some people allow to put in front of the counter, say, an automaton, but it requires placing it in an electrical panel next to the meter so that the whole thing can be sealed.
If the electrical panel is metallic, it will require grounding, which means manufacturing the grounding circuit. In general, there are many nuances, so be sure to clarify, so as not to redo it. As for the type, you should not install an old mechanical counter - if it is in your area they still “in fashion”, it will soon come out of it, and you will have to spend money on the purchase of an electronic-mechanical or electronic.
The next item. Any electric meter has its own calibration time.. The new meter has already been verified by the manufacturer, and the period until the next test begins to “snap off” from the moment of purchase of the device (according to the stamp of the date of sale in the passport). So if your device has been in the closet even for a completely new year, then it will have to be taken to an appropriate organization before installing it. It is necessary to believe and the device, it is impossible to determine the date of the previous verification - there are no corresponding calibrations on the case, there are no documents for the device. After verification, both the manufacturer and the testing organization seals the device and this seal cannot be broken!
For installation and connection in the meter there is a separate hatch with a lid. You can install the device, make the necessary switching without damaging the main seal. But when the work is finished and the electricians will accept it, they and this hatch and, perhaps, the entire electrical panel (if the device is on the street and has additional switching facilities to which you are denied access) sealed up. Now you can only take readings from the device by direct observation and no more.
The seal on the right, installed by the verifying organization, protects the instrument case from opening. The left seal covering the connection terminals was installed by the electricity supplier - DES
And the last remark. If your network is single phase, then you will only need to connect a single phase meter. If the three-phase, you have to buy a three-phase device. Is it possible to put a three-phase meter in a single-phase network? Theoretically possible. The device will regularly consider the electricity in one phase, the other two will simply be inactive. Practically - the electricity supplier will not allow it just in case. “Why, if it costs 3 times more expensive?” For them there are less misunderstandings - you can sleep better.
Electric meter installation
So, the meter is purchased, all the nuances of installation in a particular place are clarified from the electricity supplier. Suppose you decide to put a single-phase meter on the street. Here you will need an electrical panel for protection from the weather and vandals. Yes, you did not forget to ask the electricians, at what height is it possible to hang the metering device exactly their organization? Hang on the maximum allowed, since the electrical panel, especially plastic, is no protection against vandals and burglars.
Now the routine. Fix the meter in the shield along with the switching devices (if they are provided). Climb up the ladder and fix the shield on the wall in one way or another - with dowels, nails, bolts, you shoot with a mounting gun, you weld - it doesn’t matter, the main thing is that the mount is firm, reliable and durable
Here comes the dilemma: if the shield is plastic, then it will protect the meter only from the weather. If iron, it must be grounded. Which option to choose is up to you. If you have a ready ground loop at your disposal or you are able to manufacture it (in private house is not a problem, and this article does not address the issue), then, of course, it’s better metal. The meter itself, after installing the shield, must hang vertically - this is stipulated in the relevant provisions and spelled out in the passport of the device.
The metal shield (left) is stronger, but requires grounding, unlike its plastic counterpart
If you install the meter in the apartment, you can use an open electric shield. Switching and protection devices — automata, RCDs, or ordinary “traffic jams” will stand on the same shield. You will have access to them, as the electricians seal only the meter.
How to connect the electricity meter correctly
The meter is installed, it is grounded, if necessary. It remains to make the layout. Vleesha on the ladder with a voltage indicator (in the home - "indicator-screwdriver") and find out which input wire you have is zero and which is phase. Go to the electricians and ask to turn off the power supply to your country or country house, and at the same time enlist their honest word that they do not "turn on" the light without your permission. In this regard, almost all electricians adhere to clear rules and if they said that they would not turn it on, they would not turn it on.
If you turn off the light yourself, say, on a house shield, be sure to put an observerSince all these signs like “Do not turn on, people work!” for the majority of our population is nonsense. Half of the people never reads anything, and right off they click all the switches. The second half, such an impression, cannot read at all.
Back to the stepladder. Check the absence of voltage at the input and you can work. Almost all electric meters are connected in the same way. They have input and output terminals. Voltage is supplied to the input terminals from the supplier's line (input), you take energy from the output for your own needs. The terminals of single-phase meters are usually arranged in the following order.:
- Input phase wire;
- Phase output;
- Input zero wire;
- Exit zero.
Connection diagram of a single-phase meter, which can be found on the back side of the instrument cover and in the device passport
If you do not install anything up to the meter, then connect the input cable directly to the meter terminals, and you should not confuse the phase and zero! If in front of an electric meter you put, for example, an automatic machine, then wind up a cable on it, and connect the automatic machine itself with segments of single-core wire of the corresponding cross section with the meter input. Now do the wiring after the meter, connecting all kinds of protective devices, RCDs, fuses, etc. If there is nothing like this, simply connect the cable that goes to your house with the meter output terminals. For example, below is a diagram of the connection of the meter with the security system installed both before and after the meter itself.
An example of how to connect an electric meter to a single-phase network
The input automaton protects the line from short-circuit and allows de-energizing the meter and everything after it manually. Immediately behind the meter, there is a UZO protecting the house network from leakage currents, and the house network itself is divided into three lines, each of which is protected from short-circuit by its own automatic device. Please note that the ground wire (green) does not break anywhere and does not start anywhere - neither in the meter nor on the machines. It serves to ensure the safety of the use of electrical appliances and no more.
How to connect a three-phase meter
All the difference between a three-phase electric meter and a single-phase one consists only in that it has not two, but four inputs (three phases and zero) and, accordingly, four outputs:
- 1, 2 - Input / output phase A;
- 3, 4 - - // - B;
- 5.6 - - // - С;
- 7, 8 - Input / output zero.
Three-phase electronic meter from the connection terminal side
The scheme of its inclusion, which, by the way, is also in the accompanying documentation, looks like this:
How to connect the meter to a three-phase network
Do-it-yourself electric meter repair
Unfortunately, the electric meter is not the device that everyone can fix with their own hands, like, say, an iron or a desk lamp. First of all, its body is sealed and after opening the device, it will have to be carried for verification. However, this would have to be done anyway. Modern electronic and electronic mechanical counters are quite complex (not simpler than an automatic washing machine or even a mobile phone), so for its repair you need to have special knowledge of electronics in the amount Institute. Therefore, it is impossible to answer the question “How to repair an electric meter?” In the volumes of a small article, as it is impossible to sketch in three words a repair manual, for example, a PC or a GLONASS satellite.
As for mechanical devices, then, in principle, if you are familiar with the mechanics and fundamentals of electrical engineering, you can try repaired by assembling, say, two of one or simply cleaning and lubricating, because it is mechanical and most often the cause of the problem is dust and moisture. But, it is worth repeating, if you open the case of the device, it will need to be rechecked in the appropriate organization. Without opening, you can only replace burnt terminals, with which the meter is connected, but here you will have to invite a representative of the service provider (controller or electrician), who will remove his seal from the terminal cover, and after the repair is completed, put it in place, having previously checked the connection of all wires.