This is the 6th part of the series - a question-answer on electrical. In this collection, I have included 3 questions that I answered relatively recently and that I found interesting for Zen.
Question N1 was asked by Maxim:
Good afternoon, there is a task at the facility, to bring to life a design project, to illuminate the room from 220 V lamps of one group, conditionally (above the bed in bedroom), through 3 dimmers, one at the entrance to the room, the remaining two on the left and right sides by the bed, is it possible to do this and how it will look scheme? It would be nice for a specific example of a manufacturer of dimmers and lamps, thanks!
I gave the following answer:
No, if the option of connecting a pass-through dimmer still takes place in domestic networks, where only two switches are used, then three at once, this is too much. The problem is that the operation of the dimmer and its effect on the lighting scheme is fundamentally different from the classic rocker switches or buttons. Therefore, you will not be able to assemble a lighting control circuit from three or more points. One family member will twist the maximum at the entrance, and the second, by the bed, will try to do the minimum, the third will do something in between, what do you think should happen with the lighting?
I would like to note that double-point dimmers also have their drawbacks. For example, set to the maximum one of them immediately excludes the possibility of full adjustment for the second. Today, the dimming function of the lighting system is perfectly implemented in smart chandeliers. They switch from a classic rocker switch and can be controlled by a remote control - install a switch at the entrance and a remote control by the bed.
Question N2 was asked by Sergey:
Hello. The dorm room has two wires: 1 for lighting. 2 to sockets. I want to put a shield with machine guns in the room. Can these two wires be combined and brought into the shield? Phase to phase, zero to zero?
Sergei was given the following answer:
It all depends on what these lines are and how you want to combine them. If both one and the second cable are powered from the same phase, then there will be no problems. If these are different lines, then you cannot combine them, you must select one of the lines to enter into the room shield or leave each one separately. But you can combine or divide the internal distribution network at your own discretion.
Schematically it will look like this:
The scheme of combining two lines at the input:
Scheme of separate input of two lines:
Question N3 from Arsen literally:
Hello. Which lug is suitable for heat resistant steel flexible wire? Aluminum or copper? Or is it possible to pressurize both of them and there will be no problems in the future?
The answer was as follows:
For steel wires, I would recommend using a copper or tinned ferrule. Aluminum, by itself, has a lower melting point than copper, it is easily oxidized by external factors, therefore, destruction on such a tip will appear faster. If you know the brand of this wire, then the tip should be selected based on the passport data and the manufacturer's recommendations. It all depends on the range of operating temperatures that the wire itself and the terminals connected to it will experience.
But, in your case, I am tormented by some doubts, I apologize in advance for my skepticism, is this really a steel wire? The thing is that wires with steel conductors are not flexible, this parameter is usually inherent in cabling and wiring products with copper conductors. Perhaps this is a bimetallic wire, then a completely different conversation, the tip is selected according to the material of the top layer.
Also note that heat-resistant cables and wires, for the most part, are made with copper conductors or copper with the addition of an alloying material, for example, nickel. If you were guided only by color, then perhaps you should check the product passport, or at least use a magnet.
P.S. Link to the past - Part 5 and Part 4.
P.S. If you would have answered differently or supplemented these answers, then I am glad to have adequate comments below to this entry.
Let me remind you that all these questions were asked by absolutely real people. You yourself can ask the electrician at https://www.asutpp.ru/vopros-elektriku (it is important to follow the rules when filling out the question).