Sometimes, when you turn off the electric meter, you can see that the disk inside the device continues to spin. Many people don't know what it is. This phenomenon is defined as self-propelled.
Meter self-propelling is a phenomenon on an energy meter that occurs due to the fact that the moments of compensation and friction are unevenly aligned with each other.
This is an unfortunate situation because it means that you will have to pay for electricity that your network did not consume.
This process is not a rare situation: both masters of their craft and beginners in electrics often encounter self-propelled guns.
Today we will look at what a self-propelled gun is and how you can remove this error.
Types of meters
Mechanical meters are older models, so it is in such devices that more breakdowns occur. This is due, first of all, to wear and tear of the mechanism and design features. This type of device is also called induction. The mechanical counter consists of the following parts:
- current coil;
- voltage coils;
- disk;
- counting mechanism;
- permanent magnet.
All these elements are compactly installed in a housing made of dielectric material.
The design of an electronic meter differs significantly from an induction meter and contains only a few printed blocks with an electronic display. They are much more compact and have less weight.
How to independently calculate the hidden cause of a breakdown
If there are no signs of malfunction of the metering device, then you can verify the functionality of the equipment yourself. You will need to turn off electrical appliances and make sure that there is no voltage at the output. The disk should stop rotating.
Counter error calculation
After the preparatory measures, to minimize the load on the home network, connect a 75 W lamp to the outlet and count the number of revolutions made by the disk for 5 minutes.
Electricity consumption should be A1=0.00625 kWh. Calculated by multiplying the amount of time and power. The meter will display A2=Sch*N, where the first is the electricity consumption per 1 revolution, and the second is the number of revolutions for 5 minutes. For example, N=31, then A1=A2. Devices intended for use in domestic environments may be subject to errors. If the error is less than the difference between A1 and A2, the equipment works properly.
Also, to check the suitability of the meter, you should check the condition of the contacts and whether the connections are reliable.
Self-propelled meter - what is it?
Self-propelling of an electric meter is its incorrect operation, which consists of counting electricity in the absence of its consumption.
In other words, when all household appliances in a house or apartment are turned off, the meter continues to count. Of course, this is not a pleasant factor, since no one wants to pay for unconsumed electricity. Therefore, during operation, it is necessary to regularly check the device for self-propelling, so that if this problem is detected, immediately eliminate this problem and avoid troubles with the service provider.
A malfunction may appear unexpectedly, so you should always pay attention to the measuring device.
How to check the operation of an electric meter at home
Why check your electric meter?
Every month, electricity consumers experience increasing financial burden due to rising tariffs. At the same time, it very often happens that the consumer pays for electricity that he does not actually use. This happens due to a faulty electricity meter. To make sure that your electricity meters are working properly, you can test the device at home.
It is necessary to immediately clarify: in a domestic environment, it is only possible to check the metering device, which should not be confused with checking the meter itself. The latter is carried out by institutions that specialize in servicing metering devices, and it has legal force. If a consumer decides to check the correct operation of the electric meter at home, the test results can only reassure him if no breakdowns have been identified, or become a reason to organize an inspection if a significant error is detected.
The meter test can be carried out at any frequency. As a rule, the idea to arrange a check arises in the following situations:
- Energy is consumed in volumes that are not comparable with the needs of the equipment available in the house;
- The decrease in electricity consumption due to the long absence of consumers occurred disproportionately. Sometimes consumption volumes do not decrease at all;
- There was a sharp jump in electricity consumption. At the same time, recently no equipment has been purchased that could significantly increase the amount of energy consumed - bread machines, washing machines, air conditioners. Also, the number of people living in the apartment remained unchanged and it is impossible to justify the jump in electricity consumption due to a change in season, for example, due to the start of operation of heating devices.
How to identify a self-propelled gun?
You can check the electricity meter for self-propelling in the simplest way. To do this, it is necessary to turn off all devices in the house or apartment that consume electricity, that is, make the consumption zero.
Tip #1: You can also simply turn off the machine that is installed after the meter. If the device is working properly, its disk will stop spinning. You need to watch him for a few minutes. There is a mark on the disk that will facilitate visual observation. If the disk moves, then this device contains self-propelling and must be replaced.
The same operations are carried out with an electronic meter. Such a counter does not have a disk, but instead a light indicator is installed. When monitoring the device, the indicator light should not flash more than once per minute. If the indicator flashes very quickly, you should immediately contact your energy supply company.
Reasons for appearance
The reasons for the appearance of self-propelled guns in a mechanical counter are directly related to its physical properties.
In this device, a special device is installed to level friction forces - a compensator. It looks either like a special plate or a short-circuited coil. A compensator is installed in the path of the magnetic flux. When the meter is operating, the magnetic flux bifurcates into two, between which a phase shift angle appears. As a result, an additional moment appears, which compensates for the friction moment.
At a normal load of 100%, the frictional moment is completely compensated. But when consumption is zero, the compensation moment is much greater than the friction moment and, due to the difference, spontaneous spinning of the disk occurs.
To eliminate this, a special braking element is provided in the self-propelled counter.
The design of a mechanical (induction) meter assumes the presence of a plate - a compensator of friction forces
Self-propelled repair methods
When it is discovered that there is a self-propelled gun in the meter, it must be eliminated immediately. All causes that may be associated with the self-propelled vehicle must also be eliminated.
There are two ways out of this situation.
The first is, if a malfunction is detected, call an electrician who will dismantle the meter to hand it over for repair. After the repair is completed, it must be submitted for testing, which will confirm that the device is in working order. Then you should install the counter in place. In this case, during the absence of the device, another one must be installed in its place or the calculation must be carried out based on average readings.
The second method of fixing the problem is to simply replace the meter with a new one.
Tip No. 2: In most cases, a simple replacement is a more profitable and quicker solution, since the financial costs of repairs, verification, dismantling and installation often exceed the cost of the device. A large amount of time is also spent, and if you also take into account visits to various authorities, then replacement is definitely the best option.
When replacing, you need to remember that when removing the meter, you must notify the service provider if the dismantling is not carried out by them.
Also, during installation, sealing of the device is carried out only by a representative of the service provider, or by an electrician together with a representative of the supplier. A certificate must be issued for the seal installed, which indicates that all work was performed correctly.
Possible reasons
Self-propelled counting mechanism is the rotation of the electric meter disk when there is no load in the electrical network.
Disc rotation can cause the following malfunctions:
- Voltage coil failure. It creates a magnetic field around a special brake hook. If the coil is faulty, then the field will be absent. As a result, the braking effect will disappear and the disk will begin to rotate;
- A similar action is caused by a malfunction of the brake hook itself;
- A malfunction of the brake flag leads to self-propelling of the disc.
Any of the three defects can cause the meter to self-propel. This occurs if there is no light, but the counter is spinning. However, such a failure is possible only in mechanical metering devices.
It is more difficult if electronic devices show incorrect data, if there is no light, but the counter is spinning. Incorrect readings may be caused by an erroneous connection made by an electrician. The second reason is the failure of the device itself.
In the first case, an electrician is called, who must correctly connect the wires. In the second case, the counter is replaced with a new one.
But there is another reason. It may be due to a faulty cable insulation. And increased readings will indicate the presence of leakage currents in the wiring.
Old electricity meters were not so sensitive. And the leakage currents are insignificant at first. But they increase over time.
Faulty wiring will continually cause the electric meter to read too high. Increasing payments for this reason represents the lesser evil. If it is not corrected in time, it can eventually cause a short circuit or fire. This defect must be corrected. To do this, you must contact a qualified electrician.
Procedure
If the electric meter in an apartment breaks down, the algorithm of action is simple, the main thing is to do everything quickly. This is due to the fact that there may be electricity in the house, but the meter will not record it. As a result, you can receive a large fine for stealing electricity. The algorithm of actions for the resident and electrician should be as follows:
The specialist who arrived on site tries to determine the cause of the breakdown, eliminates it if possible or installs a new meter. In municipal apartment buildings, electricity meters are installed free of charge. In all other cases, you will have to purchase an electric meter yourself. If the device is repairable, but cannot be repaired on site, it is dismantled and transferred to a laboratory that is authorized to carry out such work. Upon completion of the work, it is installed in its original place. Based on the work performed, the electrician must draw up a report that describes in detail the nature of the breakdown and the appearance of the device. Before signing, carefully read what is written
Particular attention is paid to the section where it is written about security seals, whether there is any information that they were damaged. This will avoid accusations in the future.
The completed document is submitted to the management company and the Distribution Zone to record the results of the work done. If the electric meter has been replaced with a new one, it must be sealed. This procedure can only be carried out by an authorized employee of the energy supply company. Until the security seal is installed, the device is considered not to be put into operation, payment is made according to the standards approved by the state apparatus of the Russian Federation. The act of installing the protective seal records information about the date of the work; it is this that determines the period for the state inspection of the electric meter according to the established regulations.
What to do if the electric meter breaks down
A breakdown of the meter should not cause panic or any concern at all. Of course, there will be troubles that will take time and money. You will have to turn to the power engineers and most likely buy a new meter. It's okay, this is a common occurrence for controllers. The main thing is not to do anything yourself.
If in your opinion the electric meter is dangerous, be sure to turn off the power at the input before it. And contact the management company or directly to the local power grid.
Where to go to apply
As soon as you discover that the meter is faulty, call the power engineers and report the breakdown or your suspicions. After this, you will need to contact the energy supply yourself. There they will ask you to write statements. After this, you will be informed about the date of the proposed visit. All that remains is to wait for the employees and together determine further actions.
Based on the test results, you will be offered to check the device or replace it with a new one.
How to pay for electricity consumption
If you reported the fault to the power supply company in time, your electricity consumption will be calculated based on the monthly average for the last 12 months. Within three months, it will be necessary to repair (buy a new one) and install the electricity meter in place.
Standards are calculated separately for each region of the country.
Protection from external magnets
External magnets can have a very negative effect on CT instrument current transformers.
The current transformer is one of the most popular devices for measuring current in alternating voltage circuits. Its working principle is shown below:
Flowing through a bus or wire, alternating current creates a magnetic flux in the transformer core, which then induces alternating current in the secondary winding. If load current flows in the primary winding, then the primary current flows in the secondary winding, divided by N (the number of turns of the secondary winding). The output current of the current transformer will be potentially isolated from the voltages and currents of the primary circuit.
If the device is exposed to a strong external magnetic field, it can lead to saturation of the current transformer core and introduce errors in its operation. In other words, disable it.
There are several ways to combat this phenomenon:
- If the current transformer is a device built into the meter, then it is necessary to ensure its location inside the device in such a way as to limit the access of external magnetic fields. If it is not possible to achieve such an arrangement, then it is necessary to provide for its shielding from external magnetic fields.
- It is also possible to replace the current transformer with a Rogowski coil. This coil does not have a metal core, and the use of external magnetic fields will not affect its measurement accuracy in any way.
- There is an option using a measuring shunt. A low voltage resistor can be used as a shunt. This method provides a fairly accurate measurement, however it is a direct measurement method and special protections must be implemented for the control system.
- Placement near the vulnerable element of the magnetic field sensor. When the magnetic field value exceeds the permissible value (despite its polarity), the sensor will send a signal to the microcontroller that the magnetic field has exceeded the permissible value.
Models predisposed to self-propelled
There are many manufacturers that produce electricity meters.
All old-style induction meters are susceptible to self-propelling. This is due, first of all, to the design features of such devices. In addition, wear of the mechanism plays an important factor. Therefore, if you decide to replace an old-style device with a similar meter, this is not the best solution, since the appearance of self-propelled guns will arise in the near future.
You also need to take into account that an old-style induction device must be periodically verified, which means additional costs and time.
For general information, a list of the best and proven counters that have shown themselves to be positive has been compiled.
- Neva 103 1S0. This model of electronic-mechanical type is highly reliable. The main positive qualities are the dial with large signs and a convenient lid for sealing. Also, one of the advantages of this model is the ability to take readings in the absence of electricity;
The electromechanical meter Neva-103 allows you to take readings even in the absence of power supply
- Energy meter CE 101-S6. This model is very popular when installed by electricity supply companies for subscribers. The main positive qualities are minimal own energy consumption, a 5-year warranty. Devices of this model operate fully in low temperature conditions;
Electricity meters of the Energomera CE 101-S6 model are most often installed by energy supply companies
- Neva 102 1S0. This counter model is distinguished primarily by its compactness and weight of only 89 grams. The performance of this model is not inferior to its foreign counterparts. Installed in shields with a small volume of working space. This device is not widely used because for many it simply does not inspire confidence.
The compact model of the electric meter Neva 102 1S0 is installed in electrical panels even with small dimensions
It is believed that mechanical counters can be stopped using a magnet. This is not so - the counting mechanism is made of plastic, but the aluminum disk remains vulnerable. Such actions can cause damage, since the magnet negatively affects other elements.
The appearance of self-propelled vehicles can appear much faster if similar experiments are carried out.
Types of obvious breakdowns of the metering device
If the electric meter has stopped, do not worry or panic. This is a common situation that many tenants face.
There are many types of breakdowns, all of them are caused by network instability, overload, mechanical stress and damage. To determine a breakdown, in most cases it is enough just to inspect the device.
- The electric meter burned out. The contacts and housing are melted, and there is a distinct burning smell. As a rule, this process is accompanied by burnout of the electrical wires that were connected to the device. In this case, it is impossible to restore it, only change it.
- As a result of mechanical impact, the integrity of the housing was damaged. Through cracks, various chips and dents have formed on the sight glass or the body itself. In this case, the meter must be completely or partially replaced.
- As a result of overheating, the contact pads burned. This problem is caused by loose contacts between the output and input circuits of the network. The problem can be resolved without dismantling the meter.
- The meter was regularly overloaded. Induction meters are characterized by one phenomenon - the appearance of a hum, the sight glass of all devices becomes cloudy, and the smell of burnt insulation is felt. In this case, the meter is also not repairable; it is necessary to install new equipment designed for higher powers.
- The meter continues to rotate the wheel when the load is completely turned off. The reasons for this phenomenon may be damage to the integrity of internal parts, as well as circuits. The equipment may need to be repaired.
All of the listed types of breakdowns are obvious.
There are cases in which you need to immediately install a new electric meter:
- The metering device has reached its service life.
- The accuracy class of the device is less than 2.0.
Sometimes there are no obvious signs of device malfunction.
Where to contact
Application form for electric meter repair
If the electric meter does not show data, first of all, you need to inform the energy supply organization about this.
If the device in the room poses even the slightest danger: it crackles, makes noise, blinks, smokes or smells burnt, you must turn off the voltage supply at the input.
The next stage is to come to the organization yourself and fill out an application according to the sample, on the basis of which the RES employees must come home and fix the problem. The application must indicate the approximate date and time of attendance at the top.
Upon arrival, the inspector draws up a report about the malfunction of the electric meter. First, he carefully examines it and takes the last readings. When drawing up the report, it is imperative to clarify what reason for the breakdown is indicated, so that in the future there will be no disagreements and conflict situations on this basis.
