Replacing wiring and electrical panel in the apartment - current issues

Maxim asks:
Good afternoon. I plan to remake all the electrics in the apartment, because I don’t like what is. And there is the following: in the floor guard there is a counter, an introductory circuit breaker, a fire protection RCD, 2 cheap single-pole C16 circuit breakers, an earth bus, aluminum wiring to the apartment and the apartment.

I want to make a machine gun group in the apartment and lay copper wires.
In total, it turns out for all devices, lighting and sockets a little less than 100 Amperes for nominal consumption (one electric stove consumes nominally 5.5 kW, 20 A). I understand that a total power of approximately 20 kW of all devices will never be in simultaneous operation. But at a nominal value, wiring accessories and wires are selected.

The following is planned. Put a small box with machine guns in the apartment. There will be 4 consumption groups at a nominal value of 25 A each. Accordingly, it is planned to put either 4 difavtomat, or 4 groups Avtomat + RCD. It is clear that all this is redundant, but I want to make complete safety and with a margin for future lotions-consumers.

The wiring will be copper with 3 single-wire conductors (phase, zero and ground) of a good manufacturer and with non-combustible insulation. The laying will be without pipes and cable channels, under a drywall (non-combustible cable does not need additional protection with corrugation or duct). I calculated the cross sections using online calculators.

My questions:

1) What to take: difavtomaty or automatic machines + RCD? Which one to take: unipolar or bipolar (P + N)? Links to the model are desirable.
2) If the nominal value for the apartment from the meter goes 5-50 A, will it be correct to choose a cross-section of a copper cable of 6 mm square, based on a length of a maximum of 20 meters to the automatic panel in the apartment?
3) If the rating of the machine is 25 A, will it be correct to choose the cross-section of the copper cable for an apartment of 4 mm square, based on the line length of a maximum of 50 meters to all consumers, or will 2.5 mm square be enough?
4) If you put on the same line the wiring for different consumers, the cross-sections of diverging cables will be selected according to the power of the consumer? That is, is it possible to transfer 10 meters 2.5 mm square cable from the machine, and then distribute it in 4 (conditionally) sides with consumers at the ends of 1 kW (about 5 A)? What then should be the section of diverging lines?
5) Indicate if there are errors in my calculations?

The answer to the question:
Good afternoon. Everything that you wrote first of all is broken up on such concept as "Allocated power“What is the habit of everyone to consider“ I need so much because there are so many devices ”?

4 AB of 25A is not 100A, it is as many amperes as the introductory AB misses.

On sockets more than 16A can not be put! For electric stove - according to consumption. To the light of 6-10A. Need more outlets / lamps - make a separate group with a separate machine. And for all this, unipolar AB. For input, you also need a single-pole, or 2-pole (although in most cases 2P on input is a relic of the past).

Accordingly, the cable for sockets is not less than 2.5 mm and for lighting not less than 1.5 mm². You can read how to count on input here or using our calculator.

1) Difavtomats cost more, in which case you need to think about the cost of replacement, RCD + AB - usually cheaper, and the replacement will be cheaper. Yes, and more clearly you will understand the cause of the leak or short circuit. For models, look at ABB, Schneider Electric, KEAZ.

2) Understand what the maximum and nominal current of the meter is and read about the allocated power in the link above. 5-50 But these are not permissible limits for you, but only the current at which the meter was checked, and up to which it considers the accuracy class in the established class (and will not burn at the same time).

3,4,5) answered above.

We also recommend reading articles on electrical wiring and electrical panels on our website, the same thing is repeatedly repeated there for different situations.


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