I continue the popular "Question-Answer" column. And this is the 55th question from readers. Let me remind you that if you have your own answer to a question, then write it in the comments below. I and other readers will be happy to read it.
I quote the text of the question from reader Dmitry verbatim:
Hello! I would like to know. I lead the cable from the outlet to the balcony. And on the balcony, I need to plug in a switch, a socket and a floor heating. What cables to take and what section? And the wiring diagram for all this.
I considered the issue and advised Dmitry within the framework of my knowledge and qualifications as follows:
Good day!
Well, firstly, I would like to know what you are connecting to an existing wall outlet, and what power. Secondly, tell me what section of the cable goes from the junction box or from the terminal board to the same outlet. To begin with, you need to figure out what margin of dielectric strength in terms of load exists for the existing line. After that, you can evaluate the possibility of connecting balcony electrical appliances.
When determining the cross-section of the cable required to connect the balcony, you must calculate the total power from the electrical appliances connected to the outlet and the warm floor. Underfloor heating, as a rule, is given in units per linear or square meter. Therefore, for the calculation, bring the consumed power to the dimensions of the heated area.
For example, a running meter of the floor will consume 280 W, then with a balcony length of 3 m, your consumption will be 840 W. If you are going to connect a 1500 W electric kettle or a 1500 W heater to the outlet, then the total load will be 2,340 W. Then the cross-section of the cable cores can be calculated using an online calculator:
https://www.asutpp.ru/raschet-secheniya-kabelya-po-moshhnosti-i-toku.html.
The connection diagram will look like this:
From the existing socket, you take "phase" and "zero" and route them to the junction box. It is most beneficial to place it in the same room as the outlet, but if you cannot meet this requirement, use a sealed model for the balcony.
Draw two lines from the box - one to the socket on the balcony, the second to the warm floor. To regulate the heating process, I recommend that you install a key switch in the phase conductor of the balcony power line.