Hello everyone :)
Thank you again for all your suggestions :)
I made my decision (I already had to) and purchased 100 meters of YDYp 5x2.5 mm2. A separate circuit + protection for each furnace. A little, or maybe even more than a little exaggerated, but it is better to always have a spare than not to run out when it turns out that one day such an installation will be used for something else.
However, I have a few other problems that I would like to attach to this topic, and they are related to my renovation, so if you want to continue the discussion, I invite you HORRIBLY, because I need your help just as badly.
Problem # 1.
I have to connect (temporary connection - in the old switchgear) the wires: 4x4 mm2 Al on one side, and 4x4 mm2 Cu on the other. After connection, the switchgear will be covered with KG plates and will not be accessible. Not only that, this connection is in the bathroom, where (while showering), a lot of steam will probably float.
Questions:
1. What kind of connection should be used so that it is durable and does not corrode, because, as we know, Cu cannot be combined with Al?
2. How to effectively and safely secure the above-mentioned connection against moisture?
3. After the connection is made, should it be bricked up / plastered over, should it be left in the free space of the switchgear, or else something else should be done?
Problem # 2.
For halogen lighting (bathroom, hall, dressing room) 2x1.5 mm2 cables were placed, and from what a colleague wrote
michcio , it should be 3x1.5 mm2, i.e. additionally yellow-green to 2x1.5 mm2. We all know that theoretically (for it to work) 2x1.5 mm2 is enough, but I wonder if when you come from the power industry to connect a new installation, it won't cause problems for this?
Questions:
1. Do those from the power industry check such things before connecting a new installation?
2. Record on the design that there is a third strand, in fact only leave two ???
3. Should you leave two veins, apply the same number to the project and not worry about anything ???
4. Or maybe the third core should be used only for the bathroom (where there is moisture), and the other rooms should be left on two cores ???
Thanks a lot for everything