Gear ratio of the electric meter. Methods for self-checking the electric meter. Checking electric meters with current clamps

Warning: ksort() expects parameter 1 to be array, object given in /home/users/a/alekcsvit/domains/website/wp-content/plugins/yet-another-related-posts-plugin/classes/YARPP_Cache.php on line 462

If you have installed an electric meter in your apartment, this does not mean at all that the device accurately determines the consumption of electricity. When can you suspect incorrect values ​​\u200b\u200bset by the meter?

1. If the meter shows too high, then you are sure that this month the appliances powered by the mains were used in the same number and approximately the same amount of time.
2. Wanting to save money, you turn on the TV and computer less and less often, and the electric kettle and microwave are replaced with a regular one. gas oven, but the indicators of the electric meter remained the same, which is very alarming.
3. You were absent from the apartment for a long time and did not use electrical appliances, and the meter continues to wind up kilowatts.

If at least one of the points fits your situation, it's time to take up the verification of the electric meter, perhaps its accuracy, to put it mildly, is lame.

How to check the correct connection of the meter

Before scrupulously studying the meter device, check if it is connected correctly. A correct connection assumes operation in a 220 Volt or 380 Volt network, all other values ​​are invalid. Also consider the connection diagram of the meter with 1 phase, you will have to figure out where the phase is, zero, where the input is located and where the load falls.

If your option is far from the connection diagram of the device for fixing the consumption of electricity, do not put aside the solution to the problem. Today the device may show small deviations from the norm, and tomorrow you will already be subject to untold penalties, so fix problems in time.

If you are sure that the wires are connected properly, proceed to troubleshooting, as described below.

Is the disc spinning properly?

To make sure that the meter disc that records the amount of energy consumed is not spinning as it pleases, turn off circuit breakers located below the sensor, because they fall on the maintenance of sockets, lighting, electrical appliances. If individual automatic devices not in the apartment, it is enough to unplug electrical appliances from the sockets and be sure to switch the light switches to the “off” mode.

After 10-15 minutes, take a look at the counter again - does the lamp in front of the panel blink, does the counting device disk continue to rotate?

If this does not happen, it’s good, but it’s okay when the flashing repeats once every 10-15 minutes. As for the disc, it must come to a complete stop - one rotation per 10 minutes is acceptable.

If the device, despite the shutdown of the equipment, operates in the normal mode, the self-propelled by impulses is faulty, immediately contact the service institution. The latter in detail, together with special equipment, will be able to verify the operation of the electric meter, and it is better if it is carried out in a laboratory.

How to calculate deviations in measurements at home

To nullify the variant of the error in accounting for consumed electricity, stock up on the following means:

• incandescent lamp;
• multimeter of electronic format (pointer device, and even more so current clamps, are not suitable);
• formula calculator;
• stopwatch, which is found in any smartphone as a free application.

An incandescent light bulb will allow you to correctly measure the power of electrical appliances, you should not focus solely on their power in the passport, because they can lower their performance or, on the contrary, increase it during operation.

Instructions for checking the accuracy of meter readings at home look like this:

1. Measure the voltage readings using a multimeter. Most likely, instead of 220 Volts you will have a different value, so write down the real one on a piece of paper.
2. Measure the lamp current. Set the tester to ammeter mode and connect to the lamp. Let's say a value of 0.43 A will be shown.
3. Decide on the actual power of the light bulb. To do this, multiply the voltage by the current. It turns out, 223 × 0.4 = 96 volts. We see deviation from technical properties incandescent bulbs at a rate of 4%. The lamp resistance is calculated as follows: 223 / 0.4 \u003d 557.5 ohms.
4. It remains to check the electricity meter itself. Connect the lamp to the mains and note how long the sensor will blink 10 times or the disk will make 10 revolutions. Watch the voltage and record both readings.
5. Look for a fixation on the front panel of a constant value, for example, 3200 imp/kWh.
6. Based on the formula P \u003d U × U / R, calculate the actual electricity consumption. The resulting value reflects an indicator of how much the lamp consumes in the current mode. In our case, this is 223 / 223 × 557.5 = 89 watts.
7. If the check time was 2 minutes, we translate into seconds - 120 seconds. So, during this time, (89 W × 120 sec.) / 3600 = 2.97 Wh were used.
8. Determine how accurate the meter is by using the formula 100 × RPM / Constant value fixed on the front panel. 100 × 10 / 3200 = 3.13 Wh.
9. Finally, we calculate the error: (2.97 - 3.13) / 3.13 × 100 = -5%. The error can be considered minimal, the manufacturer allows deviations within 10%.

Magnetization test procedure

If electrical energy is recorded by the Energomer, Mercury or Neva metering device, they can be easily checked for magnetization. If there is a magnet in the device, stretch the needle - when the product is magnetized, the needle will immediately be attracted. After 2 days after the absence of the magnet on the dial, the magnetization will disappear, if this does not help, use a special demagnetizer.

In order not to run into claims from Energonadzor employees, experts advise buying a device with an antimagnetic seal.

How to identify an electricity thief

If you have any suggestions that a dishonest neighbor can steal electricity, you need to be able to catch a thief:

1. On the site, unscrew your plugs - not only will there be no electricity at home, but also with a neighbor, of course, he will come out to figure out what's wrong.
2. Go down to the floor below, watch what happens next.
3. If a neighbor reaches into the shield to fix the traffic jams, grab him red-handed and make a claim. It is better to record all his actions on video in case the thief turns out to be arrogant and begins to deny what he has done.

The need to check the correctness of the meter readings arises when a malfunction of its operation is suspected. And a suspicion of such a pattern may appear if the receipt for paying for electricity is significantly different from the receipt that was brought to you last month. In order to check the meter, you can contact the metrological laboratory, but accordingly, you will have to pay for the provision of the service. For those who are used to saving a budget, we suggest that you familiarize yourself with alternative ways checks.

How to check the electric meter for correct readings: preparation for the process

Before starting the test, you must make sure that the meter does not spin when household appliances are turned off. When disconnected from the network, the devices do not require electricity and the meter should not wind up kW. To leave the device energized, it is necessary to turn off the single-pole machine. Then you need to look at the counter and if it is disk, then it can make a maximum of one revolution, and if there are indicator lights on the counter, then watch their pulse. For a period of 15 minutes, the indicator should make only one pulse.

Experts recommend: if the electric meter shows a smaller amount of electricity, but you did not limit yourself in the use of electricity, then it is imperative to check the device for a crack in the case.

Before the decision to replace the meter, the energy supplying organization conducts an examination of the device. And in the event that the examination shows that mechanical influences affected the crack in the case in order to save energy and influence the indicator, then in this case the owner of the device will have to answer for the theft of electricity.

If you notice that your electric meter shows failures during operation, then checking the readings can be done at home on your own. To do this, you will need to verify the number of consumption from the previous receipt and the new one received. A simple calculation will help you determine how accurate your electronic device is. The check is the same for any installation. It could be a device electric type"Mercury", a three-phase or two-phase meter, which is very popular in apartments among the population.

Taking readings of devices, you can check the accuracy of accounting and serviceability yourself, for a more correct approach, refer to the pulses, if in the complete shutdown mode they appear often, then the device is out of order. Also, a formula can help you, which, using the imp and kwh indicators, can calculate the correct gear ratio.

Steal or not: how to check the electricity meter at home

What visible and invisible damage from non-recorded use may indicate that your testimony was affected by outside interference?

These include the following points:

1. A hole is drilled in the meter body. Such a hole is made in order to slow down the rotation of the drum with a needle.
2. The protective glass has been squashed out. Most often, this glass is squeezed out in order to insert photographic film. It leaves traces of the emulsion, which are easily detected in the laboratory during the examination.
3. The presence of another connection to the meter. With such a connection, part of the consumed electricity is not fixed. It is often hidden under plaster or plinth, but if they come to check the counter with detectors, they will easily find it.
4. Screw tension is loose. This method is used if the device does not have seals or protective type terminals that are installed by the company.

There are a huge number of methods to get around such a device, but only the company that supplies energy knows about everything. And so that problems do not appear later, it is necessary to do a visual inspection for damage at least once a month.

Checking electric meters with current clamps

In order to find out what kind of load is on the network, it is best to use clamps to measure current. Such pliers in their use do not require heavy mathematical calculations. Checking with an instrumental method gives us the opportunity to check in the fastest way and get accurate results at the same time, but not every person has such a tool at home.

Network load measurement should be carried out in the following order:

• On the device of the current meter, we set the switch to the ACA 200 mark;
• We open the pliers of the device and fix it on each phase of the network, which is connected to the meter or on an insulated wire at the entrance to the apartment, while summing up the readings of each of the phases;
• The value of the load that we received in amperes must be multiplied by the voltage in the network, the cosine is equal to 1.

In modern such equipment, clamp meters are equipped with a special button, it captures the readings. This function is used in hard-to-reach places to measure the current using such a device.

We use an electrical appliance: checking the electricity meter

To check the correct operation of the counter, you can use a conventional 100-watt light bulb. During such a check, all devices in the room should be turned off except for the switch where the light bulb is screwed in. You will also need a stopwatch.

The check must be done in the following order:

• We turn on the light bulb;
• We note the time for which the counter disk will complete 4 laps or the time from one pulse to 11;
• We calculate the result using a special formula.

You need to know that if the error exceeds 10 percent, and no matter in which direction, then the device must be changed. If you need to replace the meter, you must contact an energy saving company. This company will do its job, the necessary verification and make a decision whether the meter needs to be replaced or it is not necessary. Then after the electric installation work, an act is drawn up to replace the meter. This act should indicate: device serial numbers, device type, and other necessary information. Such as: the parameters of the dismantled and installed new equipment, the readings of 2 meters and the reason for replacing the device.

The counter should not work in self-propelled. If the reconciliation of testimony can be carried out independently, then the instrumental one can only be carried out by controllers, since it is impossible to take a word that the data is incorrect. The controller checks the device for many indicators, it counts all deviations and uses an electric rail. it will show the correctness of the work. How this happens, you can find out from the video.

How to check the electric meter (video)

Checking an electric meter with your own efforts is not as difficult as it might seem at first glance. We have described all the main methods in the article above. But learn that not everyone has the right to replace the meter, but only those owners who have at least the 3rd category in energy security. And in this case, the act indicates the name and surname of the person who performed the replacement.

Electric meters are complex devices that go through numerous checks before they are installed in your home. But it happens that the operation of the device is disrupted, and it begins to wind up extra kilowatts. At the time of buying electric meter single-phase or three-phase from a trusted manufacturer, you don’t have to worry about the accuracy of functioning. In addition, old-style devices are mostly prone to failures. But if you have doubts about the veracity of the meter readings, you can test it yourself at home.

Wiring diagram for electricity meters

Devices that record electricity consumption are installed by professional electricians and sealed by representatives of the supply organization. But sometimes it turns out that the meter is connected incorrectly. Everyone can check the correct connection of the wires; it is enough to study the connection diagram of a single-phase meter. In case of discrepancies, you should contact the service organization as soon as possible, since delay threatens with large fines. And do not try to fix the connection yourself - only authorized electricians are allowed to interfere with the operation of the recording devices.

2 ways to check the electricity meter

It happens that the counters fix the flow, which in fact is not. To avoid this, it makes sense to check the product for self-propelled. This does not require any special knowledge or tools. There are two ways to check this:

• In the first option, all circuit breakers are turned off, from which electricity goes to lighting devices and household appliances in your apartment. In this case, the light on the front panel should not blink, and the disk should not spin on the induction counter (one pulse or revolution is allowed once every 10 minutes).
• In the second option, all electrical appliances are turned off from the sockets (do not forget about the refrigerator, network filters and chargers) and check the meter when the machines are turned on. Energy consumption should not be recorded.

If the device does not pass the self-propelled test, it is necessary to contact a service organization for dismantling and a more thorough inspection.

Checking the electric meter according to the formula

A little more complicated is the device check by the formula. For calculations, you need a test device ( better lamp incandescent with reliably known power) and a stopwatch.

• Turn on the lamp and note how long the counter disk will scroll 5 times or the indicator will blink 10 times.

• Find the gear ratio on the front panel of the meter (designations r/kW*h or imp/kW*h).
• Make calculations:

E \u003d (P x T x A / 3600 - 1) x 100%

Where P is the power of an incandescent lamp (for example, 100W, that is, 0.1kW)

T - the time of one full revolution of the disk or the interval between indicator pulses (the number obtained by measuring on the stopwatch must be divided by 5 for induction counters and by 10 for electronic ones)

A is the gear ratio indicated on the panel.

Plus numbers indicate the inhibition of fixation, minus numbers indicate advance. The error of the device operation is not more than 10%. Otherwise, the device must be dismantled and replaced. You can buy an electricity meter at a price affordable to almost everyone in the LEMZ store located on the territory of the plant. In "NPK" LEMZ "meters are checked for accuracy and performance on German equipment in batches and individually. Therefore, there is a guarantee of work without failures. If your meter is working properly, but you still have to pay a lot of electricity bills, it may be worth it, thanks to which the operation of powerful household appliances (washing machine, dishwasher) at night is much cheaper.

The need to check the correctness of the readings of the electric meter may arise if a malfunction in its operation is suspected.

And such a suspicion naturally arises if the amount of money indicated in the receipt for payment for electricity differs significantly from the one that was accrued in the previous month, although electricity consumption has not objectively increased.

To check the device, you can contact the metrological laboratory, but for their work, in fairness, I must say - accurate, you will have to pay.

Therefore, you can use less expensive ways to check the performance of the electric meter:

• connection of electrical appliances with known power;
• use of current clamps (if any).

Preparation

Before checking, you need to make sure that there is no "self-propelled".

This is how the operation of the electric meter is called during the absence of electricity consumption: when all electrical appliances in the apartment are turned off from the network, and the disk continues to wind kW / h.

Leaving the meter energized, it is necessary to turn off the single-pole machines (or unscrew the plugs). After that, you should watch the counter for 15 minutes.

If it is with a disc mechanism, the disc can only make one revolution. If the device has a light indicator, we are guided by impulses. During the allotted time, there can be only one light signal.

Expert recommendation: if the meter shows less electricity consumption, and for a month you did not limit yourself in its use, you must definitely check the integrity of the meter case.

Before deciding to replace the device, the power supply company conducts an examination. If the damage found indicates that the meter has been tampered with in order to save on electricity bills, the owner of the electricity meter will have to answer for the theft of electricity.

Check for theft

What damage indicates unaccounted for electricity use?

It can be:

1. Drilled hole in body. It is done to slow down the rotation of the disk with a needle or other thin object.
2. Extruded glass on the electric meter. Usually it is squeezed out to insert a film that will slow down the disc. The photographic film leaves traces of the emulsion behind, which are necessarily found later in the laboratory.
3. Attaching the “left” wiring to the meter, as a result of which part of the energy is not recorded by the meter. Such wiring is often hidden behind plaster or plinth, but upon careful inspection by detectors, it is easy to find.
4. Loosening the tension screw. This method is used if the device does not have a company seal or a protective terminal.

There are many ways to deceive the service company, and she knows about all of them. To avoid problems in the future, you should visually inspect the electric meter for damage at least once a month.

Clamp-on diagnostics

To find out operating load on the network, it is best to use a clamp meter.

They do not require heavy mathematical calculations in their use. Such an instrumental check gives the fastest and most accurate results, however, not all people have this device at home.

Network load measurement procedure:

1. On current clamps, the range switch is set at ACA 200.
2. The pliers open and are fixed on each phase of the network connected to the electric meter (the readings of each phase will have to be summed up) or on an insulated wire at the entrance to the apartment.
3. The resulting value of the network load (in amperes) must be multiplied by the mains voltage (220 V), the cosine is 1.

Take into account: modern clamp meters are equipped with a special button that fixes the readings. Use this function in hard-to-reach places for measurements.

With an electrical appliance

To check if the electric meter is working correctly, you can use a simple incandescent lamp, its power is known - 100 watts.

At the same time, all other devices in the apartment must be disconnected from the network. Additionally, you will need a stopwatch.

The procedure for checking the electric meter:

1. The lamp turns on.
2. The time during which the electric meter disk makes 4 revolutions is recorded (or the time from 1 to 11 pulses of the light indicator).
3. We make calculations according to the formula E \u003d (P t n / 3600 - 1) 100%, where:
   • P is the power of the lamp;
   • t is the measured time;
   • n - gear ratio showing the number of revolutions (or pulses) of the device at a load of 1 kWh;
   • E - error in the operation of the electric meter (in%).

Example:

Known data: the gear ratio of the electric meter is 400 revolutions / 1 kWh, the power of the light bulb is 0.1 kW, and the time of 4 revolutions of the meter disk is 280 seconds.

Determine the time of one revolution: t = 280/4 = 70 sec.

E \u003d (0.1 70 400/3600 - 1) 100% \u003d -2.22%

The error is negative, the device works ahead of schedule by 2.22%. If the value is positive, then the device is working with braking. For more accurate results, it is better to conduct several checks using different instruments.

Note: if the error exceeds more than 10% in one direction or another, the device must be replaced.

• type, serial numbers and other parameters of the dismantled and installed device;
• meters data;
• reason for replacement and others.

It is important to know: only those homeowners who have level 3 electrical safety can change electricity meters on their own. The act of replacing the device must indicate the name of the person who carried out the electrical work.

Watch a video in which a specialist shows how to check an electricity meter at home using a wattmeter:

How can you check the accuracy of the electric meter without resorting to the help of specialists.

This article is intended, first of all, for those who, by occupation or by temperament (and peace of mind is a guarantee healthy sleep) must be taken care of.

So, if you see, suspect, that your meter counts incorrectly, and this anxiety increases, every time you give your honestly earned money to pay for electricity at the end of the month, then you should do a little investigation within your household.

Naturally, the most accurate answer for operation of your electricity meter will be given in the metrological laboratory. It costs quite a lot of money, and besides, if your suspicions are confirmed, you will have to buy a new meter. Therefore, for starters, it is better to check it on your own. And in the event that you find that your overpayment for electrical energy is significant, then with peace of mind you can buy a new meter. But this is if the warranty period for your device has already expired. And during the warranty period, you just go to the store that sold you a low-quality product, and.

Well, you've made the decision to correctness of expense accounting electrical energy . Where to start? For large industrial enterprises it's simple - they have their own metrological services. We do not consider this option. If you are connected with the electrical industry of a non-manufacturing organization or a manufacturing organization, but not big enough to have a good electrician service, then you need to do the following.

Purchase . Very useful tool. With it, you can always control the load on your networks. In our case, clamps will be needed to accurately determine the actual power of the current passing through the meter (or through the current transformers to which the meter is connected).

For ordinary citizens who want to deal with the consumption of electricity at home, but do not have the desire to buy any devices for this, it is not necessary to purchase ticks. We will consider both cases.

So, we are ready to start our experiments. What is an electricity meter check? The answer is obvious - this is a comparison of the real (actual) electricity consumption with the numbers that the scoreboard or meter shows us.

We can measure real consumption with sufficient accuracy only for a rather short period of time, because the load is constantly changing, depending on human activity. Therefore, when checking the meter, they measure the instantaneous (that is, acting in this moment time) load. This is done in two ways:

1. Using current clamps.

2. By connecting devices of known power.

In the first case, the current passing in each phase of the network in which the meter is connected is measured. The currents of all involved phases are summed up, the resulting sum is multiplied by 220 - we got the current load.

If there are no current clamps, then you need to turn on only those devices whose power we know quite accurately. These are ordinary incandescent lamps, an electric kettle, etc. But no electric motors! They distort the real picture. It’s hard for a non-electrician to understand, but believe me, it’s true.

In general, turn on as many incandescent bulbs as you can and add up their power ratings. Everything else should be disabled. So we measured the real load at a given time. It remains to find out what to compare it with. On the front panel of the meter you will find all the data necessary for the analysis of its operation. This:

A rotating disk or a pulsating light (indicator);

The gear ratio of the counter is indicated by the letter r or the letter A.

Now we need a stopwatch. With the help of a stopwatch, we measure the time of a full revolution of the disk or the time during which the indicator will produce a certain number of pulses (we select the number of pulses depending on the intensity - the more often it blinks, the more pulses you need to take for greater measurement accuracy). This is how we measure the load that the meter takes into account. These measurements should be made, if possible, simultaneously with the actual load measurement.

Now we will explain how to determine the load from the measured time. What is a transfer ratio? This is the number of revolutions of the disk or indicator pulses, for which the counter will count one kilowatt * hour. To determine the instantaneous load taken into account by the meter, you need to use the following formula:

P = (3600*N)/(A*T),

where: T - the time during which N pulses (revolutions) will occur, measured in seconds;

A - gear ratio of the counter.

That's all. Now we compare the results of both measurements. If there is a noticeable difference, then we take measurements several more times to eliminate all measurement errors. If the result is confirmed, we make an economic calculation and decide whether it is worth spending money on new electric meter. It's pretty simple once you figure it out. All you need is desire. Save for your pleasure!