Following the article on temperature control, I want to talk a little more about the control of electricity. Of course, it is more interesting to control it when you have 3 phases.

There are already a lot of articles about measuring the quality of electricity. Discrete measurements using ticks are usually suggested, for example. I didn’t see graphs that show important characteristics of electricity over time: voltage on the phase, load on the phase, voltage on zero and on protective grounding, power consumption by devices, etc. With such graphs one could notice phase distortions in time, low-high phase voltages, leakage currents to earth, analyze the causes of phase failure, etc.

The author of the article is not an electrician and does not claim to provide professional information. Although the PUE and the equipment of the ground loop had to be closely acquainted.
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In my case (as it happened), the not quite correct TN-CS scheme was made, I broke PEN into PE and N after the counter (it is on the support). But despite this, it is still very interesting where and how electricity flows in 3 phases and 5 wires. This system can even be used as a tutorial for beginners, observing the zero behavior when loading different phases. In particular, it is interesting that in the neutral wire there is always a voltage (relative to the ground). I think in gardening, as well as in apartments, there can be no complete zero on a working zero conductor at all. Accordingly, a part of electricity almost always goes from ground to ground. You begin to understand that zeroing in apartments and garden plots is life threatening.




At first glance, rather complex graphics are depicted above. In fact, everything is simple. Over- 3 phases, zero and earth. Bottom - essential electrical appliances. I have 3 phases, at the entrance there is a 3-phase switch for 32A and 3 separate machines for 25A. The load on the phases shows that the stock is still doubled.

There are many measurement goals:
• Phase load optimization
• Input Voltage Quality Control
• Protective disconnection of devices when the voltage goes beyond the limits
• Phase overload prevention
• Emergency handling
• Accounting and forecast of electricity use by various electrical appliances

Phase load optimization

When I brought 3 phases to me (there was 1 phase before), the question arose about the uniformity of the loads across the phases. Compiled a plate in Excel, painted all the loads, made calculations, painted the machines in phases. Installed in the shield protection against overloads UZM-51M 3 pieces in phases, pererazvel machines in the shield in the house and, finally, connected the smart home to the shield. Realizing that phase C sags more than A, I swap them. Now in phases B and C are important consumers (computers, network equipment, refrigerator, etc.). All of them are connected for stabilizers. Computers and network equipment are also connected to the UPS. Phase voltages (stress symmetry) are about the same. Permissible, in my opinion, a difference of 10%, i.e. 23V.

But the plan is the plan. The fact may be very different from what is planned. Therefore, of course, it is interesting to see how the phases actually behave at the time of high loads. Sometimes it’s just a quick glance to see if there were 250V outlets above and 190V down. In any case, it becomes clear that it is impossible to achieve full stress symmetry even in a single garden plot. Consequently, a nonzero working zero at the input adds its own nonzero zero (geometrically). Sometimes, the geometric addition of stresses at zero can lead to almost zero, but this will be an accident.

Protective shutdown devices when the voltage goes beyond the limits

In cases when the voltage on the phase falls and keeps below, say 180V, I turn off the dehumidifiers and the secondary refrigerator, since there are no stabilizers in front of them. I send a message to the mail about what happened and then I can make a decision on how to turn them on manually.

I have automatic phase protection (UZM), but it makes no sense to turn off the entire phase if the voltage goes below the lower limits, say, 180V. Lighting lamps, devices for stabilizers are quite able to work at such voltages. UZM at me turns off the phase at 160V (on it you can manually set the permissible voltage limits). When the voltage per phase reaches normal values, the ultrasound scanner will automatically turn on after a specified period of time.

Phase overload prevention

When I had 1 phase and the incoming machine was at 25A, it was very important not to allow a prolonged overload so that the input machine did not turn off. So I managed to warm up the house gradually by the weekend. For example, the boiler and the first floor warmed up to 15 degrees from Wednesday to Thursday, from Thursday to Friday the second floor warmed to 15 ° C, and on Friday it was heated to 20 ° C at home. On Friday evening we came to a warm home. 25A was enough for me for 4 years. House 7 * 9, 2 floors, Leningrad region.

This summer I spent 3 phases for myself. It turned out 3 * 25A. But all the same there are cases when the total load on the phase can be higher than 25A. For example, I will turn on the 1.5 kW boiler (now it is 0.6 kW) and forget about it, the kids will turn on the 1.5 kW heater by accident, and the wife will start cooking in the kitchen, turn on the 2.5 kW electric grill for an hour and start vacuuming And all this happens by chance on one phase. My smart home will immediately turn off the boiler and heater. So even in this case it is useful to have control of the load on the phases.

Emergency handling.

Different abnormal situations are possible. For example, children, spoiling, will disconnect a heater. The smart home will let me know in writing. Or vice versa, turn it on to the full. The house will turn off the heater and let me know.

Often there are cases that the heating water cable fails and stops heating. How to find out about it in time, until it broke the pipe? Smart home on guard.

There are situations when the drainage pump will swallow the airlock and will try to pump out water for days. In this case, the smart home will turn off the pump after a specified time, after 5 minutes.

And, of course, it will turn off compressor installations at reduced voltage, for example, if it is below 180V, informing the owner of this.

Accounting and forecast of electricity use by various electrical appliances

Long-term observations of energy consumption make it possible to understand what makes up the amount of electricity costs and optimize these costs. The forecast of expenses allows to pay in time the electric power. In our gardening it is customary to pay in advance. I, for example, pay for several months in advance, so that later in the winter I don’t look for an accountant.

Well, now let's see the pictures with indicators measurement graphs.

The picture shows a very good time for analysis, when our gardening was planted on a “fallen” feeder. Several times in phase C, the voltage dropped right up to 160V, which led not only to the shutdown of some UPS, before which there was no stabilizer, but also to the shutdown of UZM-51M, i.e. the whole phase was shut off in the house. This is done to protect electrical equipment, in particular, refrigerators. It is known that at such voltages the compressor winding may ignite. At the same time, the difference between the minimum and maximum voltages often exceeded 20%. Then they put us back on a normal feeder.

Protective Zero, Phase and Work Zero.

Work zero is grounded. The picture shows the current on the ground loop. It shows that there is a current between the working zero and the ground loop. And this current is rather big. Here I, as a non-professional electrician, make 2 conclusions. The first - protective grounding works. And the second - there is a fairly large current. I think that there are many professional electricians who will comment on all this. Perhaps something needs to be changed. But, if it were not for these measurements for a long time, I could not know about it. Maybe this is not a problem. I just want to say that I do not yet have a potential equalization system. Of the iron objects only gas stove, stove and collectors in the water supply system.

Zero behavior

Since I am not an electrician, I was pleased with the opportunity to play with zero. See what will happen with zero, if you load one phase, and if two? It turns out that zero runs behind these phases. In general, this is understandable. It is interesting to try to load symmetrically all 3 phases. It will not work out quite symmetrically, but it is clear that in this case the zero goes to zero.

Power factor

“The power factor is equal to the ratio of active power consumed by the electrical receiver to the total power. Active power is spent on work. ” And in the picture we see that oil heaters and fan heaters have a power factor of almost 1. Infrared heater is about 0.91. But the thermal stream in standby mode - 0.45. Computers and televisions will have from 0.5 to 0.7. For professionals - this is a common thing. For mere mortals - an interesting fact.

Total consumption of electrical appliances per day

The graph shows the total consumption of significant consumers per day. On Saturday, at 0:00 am, the preheating of the house, the boiler, and the thermopot was switched on. We arrived on a Saturday at noon. At 7 in the morning, preparation for the house came to our arrival, since ended preferential night mode. The house is almost out at a given temperature. The boiler warmed up as early as 5 in the morning, the thermal steam at one in the morning. While it is not very cold outside, the house does not heat up during the day, while we are not there. During the day it was spent a little more than 30 kW / hour.

Earlier, while there was no smart home, when leaving the dacha, every time I was tormented by the thought that I had forgotten to turn something off. And, it must be said, it happened that, truth, for a week, the turned on unnecessary electrical appliances. Smart home allows you to find even such insignificant loads, as the left lighting. Especially the heater. After the introduction of the smart home, I'm leaving quite calmly. Even if something is left on (by mistake settings), then I will do everything remotely, reconfigure, disconnect. I must say, life has become much calmer.

Electricity consumption forecast for the current month

Visual statistics of electricity consumption for the previous month, at the current moment and the forecast for the current month in rubles and in watts. The only disadvantage of this smart home is that there is no concept of a night tariff. That is, if in September 621r was spent on electricity, then about a third should be deducted from there, since The main expense was at night at half the rate.

Findings.

1. An interesting toy that allows you to get interested in electricity and a little understand it;
2. A useful thing that allows you to prevent accidents and abnormal situations;
3. Having the account, it is possible to seriously optimize the cost of electricity;
4. If there is already a smart home (it is engaged in heating), then it is possible to get accounting, analysis and control of electricity consumption for almost just so.

Finally, I want to place a riddle:



Question: what happened, why did the electricity go out? At 9:23 the controller was turned off, at 9:35. I’ll say right away that I don’t know the exact answer myself. I was not there at that moment. There are only assumptions.