How to choose the cross-section of the input cable to a private house of 15 kW?

Alexey asks:

Good afternoon, experts in their field. The power cable must be brought into the house (a two-story house, allocated power of 15 kW at 380 V) in the first years it will be heated by an electric boiler of 12 kW + all the necessary equipment for life. The machine is at the input 32 A, it will also go into the house to the electrical panel.

I bought a copper power cable 5 * 16 - 25 m.
Actually the question, which is already the second day, is puzzling me - is it not a big fat cable for 15 kW or is it better to pay extra and buy a proper 5 * 10 mm2 power cable.

The answer to the question:

Hello! Why pay extra for a LESS section? What does it mean, “Isn't it very fat?” In three phases, about 2.5-4 mm² is sufficient for 15 kW. But in this case it doesn’t mean worse anymore, there isn’t a very large cross section in electricity, they take a suitable load capacity only from a financial point of view, since buying a cable with a cross section is more than expensive.

In addition, when a self-supporting cable is introduced by air, a cross section of 16 mm² is chosen, for a self-supporting insulated wire, in most cases, not because of power limitations, but because they do not produce a smaller cross-section according to GOST, plus there are requirements for this in the PUE about the cross section of conductive conductors.

How will you lay this copper? What kind of cable though?

I guess VVGng-LS.

Do you know that an SIP wire is used for branching to the input, since it involves laying by air and operation under the influence of ultraviolet radiation, precipitation and frost? If underground in the pipe you have organized input - then it is permissible. If through the air, then on the cable and in the black PND corrugation.

By the way, in addition to the input machine, is there something that limits the allocated power? Since 32A with three phases is 21 kW ...

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