Popular about apartment wiring

Dear Jacob,

what nafig diameter of the cores?

Diameter - a straight line segment connecting a pair of points of the circle most distant from each other, as well as the length of this segment. The diameter always goes through the center of the circle. It is easy to measure with a caliper. Unit of measurement - mm.

Knowing the diameter (d) can determine the cross-sectional area of ​​the cores (s) according to the formula s = (pi x d x d ) / 4, mm2 The pi is 3.1415926535897932384626 ... and then many more numbers. When calculating usually take into account two digits after the decimal point. As a result, the calculation formula core cross sections can be simplified to s = 0,785 x d, mm2.

Core diameter - technical characteristic of cable and wire products (given in reference books). For example, for VVG cable the number of cores, cross-section, diameter, rated voltage, specific gravity is indicated. The number of cores and the cross section are encoded in the cable name itself. In addition, holding a cable or wire in the hands of a person is easiest to measure the diameter, and then approximately determine the cross section of the wire. Moreover, the accuracy of the calculation depends on the accuracy of the measurement.

This one withThe article is written for people without an electrical education. In fact, this is just a small introduction to the topic for all interested, so the goal was to present everything as simple and accessible as possible.

P.S. The values ​​of the cross section of the wire and its diameter (from the guide to wires and cables): 0.75 mm2 - 0.97 mm, 1.0mm2 - 1.13mm 1.5mm2 - 1.38 mm, 2.5 mm2 - 1.78 mm, 4.0mm2 - 2.25mm 6.0mm2 - 2.76 mm, 10.0 mm2 - 3.57 mm, 16.0 mm2 - 4.5 mm, 25.0mm2 - 5.65mm

Hello!

I found your site on the Internet and decided to contact you with the following question:

There is a two-room apartment in a typical house P-44.Unfortunately, it so happened that its previous owners transferred the sockets and, apparently, were not friends at all with their heads. I will explain why. Part of the wiring is separated by an aluminum wire, and part by copper. I cannot logically explain why this was done. Despite the fact that the house itself is exclusively aluminum. And at the entrance to the apartment, too. Outlets literally moved to the floor level. EVEN IN THE BATHROOM! Over time, problems began to be observed in the electrician throughout the apartment: either the light cuts out, or the wiring somewhere in the socket burns out (apparently because there is an aluminum-copper twist somewhere in the wall) and the socket stops working . All this horror must be put in order. And here I have a question. I can use a hidden wiring probe, but the only trouble is that I don’t know where, according to the plan, the P-44 house should initially have sockets. I do not think that these people led the wiring from entering the apartment themselves - most likely from old outlets and transferred. So I need an electrician plan in the P-44 house. The second question is: how realistic is it to change ALL wiring in the apartment? Maybe in these houses it is already possible to somehow stretch the wires without breaking the walls? If so, I would like to receive any recommendations on this issue.

Good afternoon, Jacob!
I would like to discuss the possibilities of cooperation between your site and the magazine "Master to myself," which I am the editor of.
Bubnov Nikolay.

Guys to replace the wiring, call specialists and you will be happy. And then yourself do so many troubles that you can then disentangle half your life. And what is written on the site is rather for acquaintance and information is so for general development. Without a special electrical education, you can only change bulbs, and then approaching with all seriousness and responsibility to this issue. There is such a rule - "not sure - do not go." In Soviet times, everyone should have been able to do everything themselves. When working electrically, such homemade products end up very poorly.

2Artemius.

 I don’t know where according to the plan in the house P-44 there should have been sockets initially

Go to the neighbors below or above and see ...

 need an electrician plan in house P-44

Hope for plans, but don’t go wrong ... The plan is one thing, but how an electrician is drawn is actually quite another, he himself has repeatedly faced completely different wiring in the same apartments ..

In general, I strongly recommend that you turn to specialists, electricity dislikes amateur performances and amateur artists who do this amateur activities.

The electrical wiring in apartments is usually carried out by a wire with a cross-section of 2.5 sq. Mm., Under the diameter of this section, all household installation elements, sockets, switches, lampholders, etc. are made (which of course does not apply to electric cookers which are fed through separate lines), the choice of a circuit breaker for protecting wiring is based on the maximum permissible continuous current for wires and cables for heating, which depends not only on the cross section of current-carrying conductors, but also on the type of insulation and laying methods . In the PUE (Electrical Installation Rules [this is the "Charter" for electricians of all stripes] - of any year of release, since the laws of physics have remained the same), in chapter 1.3 there are detailed tables for choosing conductors. Based on the foregoing, and if you carefully review the PUE, we can conclude that for all types of insulation of the wiring (including rubber), and with any method of installation, for wires with aluminum conductors, you can safely vibrate a 16A circuit breaker. All lighting panels for industrial-made apartments are equipped with automatic machines for such a current. This also implies the maximum load of household electric consumers, 220V * 16A = 3520 W [3.5 kW].It is impossible to exceed it by increasing the cross-section of the conductors in the apartment and increasing the current of the circuit breakers, since the conductors and protective equipment suitable for the house are designed specifically for this load.
In general, the article is necessary and informative.
An experienced electrician

Hello, I live in a panel house. Counters handed out in a shield at the forester. And the apartment has 2 wires. I read that there is land on the shield (the flight path), which, in principle, can be used for your own needs, but I have not found exactly where it is or how to find / check it. Tell me, please, how?

And why do you need land there? It will be accurate if someone poured it there. But seriously, it is impossible to change the apartment wiring diagram by dividing the PEN conductor (zero wire in the riser) into N and PE. In the event that the neutral wire is broken or burned off in the ASU or somewhere in the riser, you will get a phase on the body of all connected power receivers. Any changes to the design made and approved scheme in the floor shield are illegal!

“Why do you need land there?”
For a boiler, washing machine, stove ... I think we can go somewhere else, to a computer, for example. If you can’t from the shield, tell me where to find the “ground” on the 8th floor of the 9th floor of the house.

For the boiler, washing machine and other electrical appliances in your apartment you need not grounding, but grounding. These are different things. According to the PUE, the use of grounding without grounding is prohibited. You can only zero out your home appliances if you have a TN-C-S system in your entrance, i.e. Three wires should go to the apartment from the shield (phase, N - working zero and PE-protective zero). If you have only 2 wires going to the apartment from the shield (phase and zero), then you have an outdated TN-C system. You cannot turn it into a TN-C-S in a floor shield. In no case can you use self-made grounding devices, water supply and heating pipes as a PE conductor. All this can lead to very serious consequences. The only thing you can do in terms of electrical safety is to plug in an outlet for the same UZO washing machine, and then wait for the wiring at the entrance to be transferred to the TN-C-S system.

You can also see this article and especially its comments: RCD in two-wire: to put or not to put?

It is strange that the author, paying attention to the importance of matching the wire cross-section to the current of the circuit breaker, advises for 16-amp (and even in the best case!) Outlets AS MINIMUM 25-amp AB. This device should be selected according to the "weakest link" of the system - in this case (that is, if the wire cross section is at least 1.5 square meters) this will be the outlet.

And what bothers you, there may be several simultaneously working outlets, and which household appliances are more than 3 kW (except for an electric stove and other equipment for which a separate line is needed) in order to overload the outlet?

Here this moment is more interesting:

"trunk, say, at 4mm2 to the junction box, and from the junction box to the premises, already extend the cable 2.5 mm2" 

Why is a cable of a larger cross section, if the machine will work when the load current is the limit for a cable with a cross section of 2.5 mm?

Without a special electrical education, you can’t even change bulbs - according to the rules, they must be changed in safety glasses. Personally, I recommend that my customers simply blink in order not to be left without eyes when the lamp explodes.

Electrician,
PUEs do not help when choosing a cable - there are only wires laid openly and in pipes, but cables that are walled in the walls, sometimes in hot places, are needed. Personally, I use the empirical table of the Kapro network in Kiev -VVG3x1.5 = 3kW, VVG3x2.5 = 5kw

Electrician,
It is very dangerous to put 16A machines on the lighting line - very thin wires are found in the luminaires, up to Al 0.5 square meters. Therefore, 10A, not more, even 6A.

When repairing Al-wiring, it is very risky to take a cable with cores of the same metal that is already laid to you. If it is said that aluminum is not metal for apartments, then you need to take copper for all cases and make improved contact. Personally, I serve copper, twist with aluminum and do not give a long guarantee of performance.

Svyatoslav,
See how the zero wire goes in the shield. If it is mounted directly on the shield housing without an insulator, then protective grounding can be removed from the housing. Or find a well-grounded armature in the wall in the apartment, and take the grounding of the apartment from it, with a regular check of its safety.

andy78,
The use of grounding without grounding was prohibited by the old PUE. In a new fashion in 5-wire TN-S networks there is no grounding.

The outlet can be completely overloaded if you feed the apartment through it and the extension cord. For example, in old houses with 2-3 introductory automatic devices, in the event of an accident in the outlet group, there remains one active outlet on the lighting line (between the bathroom and the toilet). Here it is that they are fully loaded, especially in winter, with oil radiators in each room, etc.

elalex,

Sorry, I’m serving a soldering iron.

16A = 3800W when the distance of the supply line is 25 meters and the cross-section of aluminum wire is 2.5 cm2 calculation for new wires is not rotten, decrepit soft (standard for Soviet-built houses)

As for the route of the wires, then with hidden laying of wires in thin-walled (up to 80 mm) partitions, the route should run parallel to the architectural and construction lines. The distance of horizontally laid wires from the ceiling can not exceed 150 mm. In building structures with a thickness of over 80 mm, the wires extend along the shortest routes.

How many amperes does the electric meter cost, how many amperes do wires need to be pulled along the rezetki. This will solve the headache if in the future you want to connect something powerful to the outlet. Why bother which wire, how many amperes. On a single-phase meter, everything is already indicated no more than 50A.