Why does an electric meter on a support overestimate the readings?
Hello dear subscribers and guests of my channel! Today I want to talk with you about a burning topic, namely, the overestimation of meter readings installed on facades or, most often, on supports.
They put a counter and he began to count more - probably something was tweaked there!
Quite often I hear a story that I had a good old counter there, for example, like CO-505 and did not know grief. At the same time, he paid himself a month for 70-100 kW of consumed energy, and these "monsters" (electricians) arrived, put a new meter on the post (facade) and he began to wind twice as much. Probably, they did it on purpose so that he overestimated the testimony.
Or, here's another very popular overstatement argument:
They put the meter in an unheated box. He will freeze there in the cold (overheat in the sun) and then he will naturally count upwards.
Let's figure out what is true and what is speculation
So, to begin with, let's go over the overestimated indicators when replacing the meters. So the first and main reason why the new meter winds up much more kilowatts than the old (ancient) is the difference in accuracy classes.
The higher the accuracy class, the more sensitive the meter, which means that if the old meter did not take into account, for example, one LED light on in the hallway, now even the charger current of the phone in standby mode will be taken into account.
Now, just mentally calculate how many gadgets you have connected to the network and gradually consume energy in standby mode.
So this is why the new metering device can wind up to 50% more than the old metering device twisted.
Exposure to heat and cold
Also, many believe that since the metering device is outside the heated room as required by the PUE 1.5.27, then the metering device will shamelessly overestimate the readings.
So, modern metering devices have long been produced with the expectation of operation in extreme temperature conditions. And if you open the passport for the device (or look at its technical characteristics on the Internet), you will see that the temperature range there can vary over a very large range:
Now let's look at another extremely curious option for winding meter readings.
Worldwide conspiracy and remote twisting of readings
Since now so-called smart metering devices are mainly installed on the poles, there is a stable the opinion that energosbyt remotely hacks and tweaks the readings in order to thereby cover their losses.
So any outside interference is prohibited at the legislative level. The readings of smart metering devices are stored in non-volatile memory, and the data transmission / reception channel is protected by an encryption protocol in accordance with the standards.
Therefore, the option of hacking and deliberately changing the readings is extremely small, although it is not completely excluded.
As you can see, the two above-described arguments are dispelled as a myth (we will single out reprogramming into a separate class of conditionally possible). Well, now I want to tell you about the option when the counter installed on the support will overestimate the readings.
When the meter is on a support, it will actually overestimate the readings
So, the meter will twist more only if several conditions coincide, namely:
1. You have a meter with two transformers installed, which means that the energy consumption is measured along the phase and neutral conductors.
2. If your meter was previously installed in a switchboard, where the zero was re-ground (according to the common grounding system in Russia TN-C-S).
3. Your sales organization refuses to split the PEN-conductor into a working zero (N) and into a protective conductor (PE) in a new switchboard, but requires that the neutral wire immediately enter the meter.
So in this case, single-phase meters with two transformers will take into account the currents flowing through the zero terminal from the common PEN to your ground loop.
In order to avoid this, there are two options:
- Reconnect the metering device according to the passport scheme so that it does not take into account the current at zero;
- Disconnect the zero ground immediately after the meter. I must say right away that this option is extremely undesirable, but in special cases it has the right to life;
- It is also, of course, possible to supply a metering device with one transformer, but since September 2020 the purchase and installation of meters will be the responsibility of sales organizations, I think this option is more irrelevant.
Note. Three-phase meters are not considered in this issue, since they do not install a transformer on the neutral conductor in principle.
Conclusion
So, I hope I answered the question: "Why can a meter installed on a pole overestimate the readings?" and along the way dispelled several myths. If you liked the material, then do not forget to rate it like and repost. Also in the comments write your opinion on this issue.