Understanding the Functionality of Installations Without a Neutral Conductor

Hello. I'm asking a question here because I don't understand how it might work. How can an installation function in which the role of the neutral conductor is provided by the earth electrode?

In my country, an elderly gentleman has a carpentry shop at the back of the house. The so-called "strength" or three phases. There is no neutral or protective conductor in the line. Everything is rather aluminum. Three-phase carpentry motors run on this installation. They do not require neutral. I understand how it works. There is also a protective earthing in the plant: a hoop belt dug deep into the ground. And so far I understand the functioning.

It is cold in the plant, so in the winter, the aforementioned gentleman connects a farelka. It has two sockets, both made in such a way that the phase is taken from the L1 wire that comes to the overlap, and where the neutral wire should be, there is simply a wire connected / screwed to this hoop, which acts as an earth electrode. I have not seen anything like this. Is it possible that normally devices such as an air heater could work like this? Can someone explain it to me?

And the second question - because it all smacks of some kind of threat to my life. Are such installations something that was normally made during the Polish People's Republic or rather a modern invention? Apparently, it has been functioning efficiently for years.

Thanks in advance for the tips.

They will work, but the standards meet it, but from 50 years ago.

leburaque wrote:

The so-called "strength" or three phases. There is no neutral or protective conductor in the line.

He has 3 wires drawn to the plant. How many wires does he have in the house? How to connect home appliances - also one to the phase and the other to the hoop?

Protective earthing must meet certain conditions. Even long ago they were defined. And it should only work as a protective one.

On the other hand, if it is "good", has a low and stable resistance, then it is possible to power the socket in this way. A 2kW farelka takes approx. 8.69 A and has a resistance of 26.46 ohms. If the ground is for example 5 ohms (I ignore the ground resistance in the transformer station), then a current of 7.31 A will flow through it and the power will be 1680W. It will heat a little less, but it will continue to heat.

Such a thing should not work - damage to the ground or even an increase in its resistance may cause an electric shock.

brofran wrote:

He has 3 wires drawn to the plant. How many wires does he have in the house? How to connect home appliances - also one to the phase and the other to the hoop?

I'm not sure, but I saw a new box at the entrance there, so the installation in the house seems to be new already. There is also a box with a counter outside. I think the home power industry pulled the electricity correctly, but I will not let my hand cut off because I did not see it. But how it turned out that they connected the house and left the plant, I do not know.

TWK wrote:

On the other hand, if it is "good", has a low and stable resistance, then it is possible to power the socket in this way. A 2kW farelka takes approx. 8.69 A and has a resistance of 26.46 ohms. If the ground is for example 5 ohms (I ignore the ground resistance in the transformer station), then a current of 7.31 A will flow through it and the power will be 1680W. It will heat a little less, but it will continue to heat.

It seems to me that we had something like that in the technical school. Would you be so kind as to explain to me what formula it is counted from? Because I do not understand a bit, and I have such a doubt: if the "earth" has a limited possibility of accepting the load, how is it that it is considered protective, e.g. in relation to a washing machine? Is it a question of grounding? Crow's face, I guess I don't understand that ... :)

Anyway - the older gentleman then told me that "what to do here, how it works". And I had absolutely no argument for that

leburaque wrote:

It seems to me that we had something like that in the technical school. Would you be so kind as to explain to me what formula it is counted from? Because I do not understand a bit, and I have such a doubt: if the "earth" has a limited possibility of accepting the load, how is it that it is considered protective, e.g. in relation to a washing machine? Is it a question of grounding? Crow's face, I guess I don't understand that ...

The earth has its own potential which is also the potential of the neutral point of the network (grounding used on transformers, poles, etc., aims to equalize the potential of the earth with the potential of the neutral point, ie "0"). However, the earth has its own resistance (resistance) which is taken into account when making earth electrodes. I don't quite understand what your statement means:

leburaque wrote:

earth "has a limited capacity to accept the load, how is it that it is considered protective, for example for a washing machine?

Simply, in order for the earth electrode to fulfill its protective function, it must have sufficiently low resistance. For this purpose, if the earth resistance measurements show too high a value, the "additional earthing" is distributed, the rods are hammered to a greater depth, additional rods are added, the hoop is extended for a longer length to "increase the ground contact area with the earth", then the earth electrode with a larger area can transmit / conduct current to earth and the earth resistance is reduced.
Patterns you asked your friend about leburaque I = U / R; P = U * I * cos. fi (for 1-phase circuit cos. fi = 1)
I hope I didn't mix up anything, the translation "to peasant reason" but I think it will help a bit

KuReK93 wrote:

(for 1-phase circuit cos. phi = 1)

Definitely?

leburaque wrote:

Would you be so kind as to explain to me what formula it is counted from?

P = U * I => I = P / U
I = U / R => R = U / I
for series connection of resistors: R = R1 + R2

slawek723 wrote:

for 1-phase circuit cos. fi = 1

Rather for a resistive receiver - and I assumed that this is the farelka.

leburaque wrote:

Anyway - the older gentleman then told me that "what to do here, how it works". And I had absolutely no argument for that

Any damage to the earth electrode causes a dangerous voltage to appear on the accessible conductive parts. This is a sufficient argument.

TWK wrote:

leburaque wrote:

Would you be so kind as to explain to me what formula it is counted from?

P = U * I => I = P / U
I = U / R => R = U / I
for series connection of resistors: R = R1 + R2

slawek723 wrote:

for 1-phase circuit cos. fi = 1

Rather for a resistive receiver - and I assumed that this is the farelka.

leburaque wrote:

Anyway - the older gentleman then told me that "what to do here, how it works". And I had absolutely no argument for that

Any damage to the earth electrode causes a dangerous voltage to appear on the accessible conductive parts. This is a sufficient argument.

I did not write or quote any formulas

KuReK93 wrote:

P = U * I * cos. fi (for 1-phase circuit cos. fi = 1)

I forgot to add that for the resistor receiver, I gave the formula for this particular case, moreover, my colleague TWK explained it for me

Such a solution of Farelka's power supply (use of protective earthing) is completely inconsistent with the regulations and may result in the occurrence of dangerous touch voltages on the accessible conductive parts of the devices protected with protective earthing. The fact that the Farelka powered in this way works is due to the fact that the neutral point of the MV / LV supply transformer is directly grounded ...

Bronek22 wrote:

Because all networks except IT have this grounded point, even TT.

I don't get something here. It's like this grounding after all - are all networks grounded, or not all? OK - sorry I mixed up IT with TT.

Maybe I can propose a 3-phase fare to this gentleman?

brofran wrote:

Bronek22 wrote:

Because all networks except IT have this grounded point, even TT.

I don't get something here. It's like this grounding after all - are all networks grounded, or not all?

After all, he wrote that all except IT.

The IT has a transformer neutral point isolated by a spark gap fuse. which means the first letter, the second is the earthing of each device (T - earthing, I - connection via spark gap, N - neutral) TN - transformer neutral point earthed, devices are earthed

So I understand that there should be voltage on the ground, i.e. this hoop, while the farelka is working? Sorry if that's a stupid question.

Due to the fact that the earth electrode has resistance, there is a voltage drop across it, which may cause a dangerous step voltage

the lightning strike in the picture is the connection point of the farelka to the Earth.

I doubt there is no N or PEN conductor.
Unless it's an IT system, which is very unlikely.

11111olo wrote:

They will work, but the standards meet it, but from 50 years ago.

Doubts whether even those are fulfilled.

what about the ZE meter ...

lukiiiii wrote:

Due to the fact that the earth electrode has resistance, there is a voltage drop across it, which may cause a dangerous step voltage

the lightning strike in the picture is the connection point of the farelka to the Earth.

Stepping dangerous at 230 volts is practically unlikely.

Touch will occur 10 m from the earth electrode.
I have never heard of someone being shocked by the tension of the touch. I do not say that it is safe.
But, for example, in the simplest transformer welding machine, the voltage reaches 70 V
and no one warns you that it is dangerous.

You have to explain to your grandfather that his solution is not very economical.
He loses a lot of energy in the ground and pays.

Bronek22 wrote:

Buddy, you want to understand too much without knowing the basics.

This corresponds exactly to feeding the device from phase through a resistor. Located on the ground side. This resistor is the earth resistance. Which may even be of great value.
Earth is a guide. But the "input to earth" itself is through a resistor, that is, through the earth electrode = earth resistance.
Example: The layer on the surface of the earth has sand, and the bottom is clay.
Therefore, there will be a lot of resistance to this not badly conductive clay.

Thank you very much for all these comments. Over the past week, I've tried a little bit of knowledge to get it all figured out. Useful knowledge.

As for the closure of the case, I made a deal with the old man explaining to him that it was expensive. And that convinced him. Because he did not want to hear about the danger.

Gentlemen - as always, I bow my head.

If no one adds any valuable information until tomorrow, I close the topic. I already understood what I meant.