Why it is dangerous to use tees and extension cords in an apartment

the title of the article does not match the content)))
non-working and improperly selected automatic machines have nothing to do with carrying.
The main drawback of store transfers is that they usually have a cable cross-section of 1.5 or even less, while the wiring in the apartment is at least 2.5
as a result, the machine (correctly selected) is designed for a cross-section of 2.5 and 1.5 is slipped into it, and this is why fires))
if you can do it yourself with a do-it-yourself transfer))) with a 2.5-4 wire, then nothing will happen to the carrying ... ... but it can happen already with the wiring in the apartment CASE !! "crooked" machine))
and if the carrying is normal and the machines chosen correctly are afraid of nothing)))

Yes, indeed, I wanted to read about extension cords, and not about machines.

If you write, then write on the topic.

Electrik You just do not understand what the article is about. It is about extension cords, not about machines. Read carefully! Naturally, everything in life is interconnected and it is very difficult to explain the danger of an overloaded extension cord without mentioning automatic machines in the article ;-)

P.s. Yes, I deleted the link from your comment, it’s just not the topic. If you want to refer to a useful site in a comment, justify what you like so much.

Mostly on sale there are extensions with a wire cross-section of 1 square. mm, occasionally 1.5 square meters. mm
In our country, where in old apartments there is one outlet for the entire kitchen, well, unfortunately, you can not do without tees, pads and extension cords. Just the choice of this product needs to be approached responsibly: look carefully at the labeling, appearance of the products and wires. Take the extension cord with a wire of at least 1.5 square meters. mm with a pad and fork, designed for 16 A. And do not save on these things, especially since now the corresponding products from eminent manufacturers that value their reputation and monitor quality have appeared on sale.

Uncontrolled use of extension cords is very dangerous. Extension cords create too much load on the base outlet, which is not rated for current in such conditions.

If you use an extension cord to connect powerful appliances (from 1 kW - as is often the case in winter when radiators, heaters, etc. are connected), never fold the excess wire with rings, a coil - in this case, the wires are significantly heated due to mutual induction.

Everything needs a measure. Of course, if you connect a microwave, washing machine and refrigerator to the extension cord at the same time, then this is a direct road to fire. And if, for example, a power supply unit for a radiotelephone, a charger for a cell phone and a radio (modern, semiconductor)? What will be the total current? Or for each charge and low-power PSU do your outlet? This is a perversion!

knotik, vending machines have nothing to do.
And I agree with the author that they even have one - this is one big problem of matching automatic machines, wires, tees and extension cords. You need to either rely on smart operation (people will add up the power of consumers, I don’t believe in that), or put up protection against the fool - put automatic machines no more than B13 on outlet lines for any cross-section and material of wires, and make more of such lines.
Personally, I make two power lines of 1.5 sq. Copper and a dozen outlets in each room of the apartment. Each power supply has its own outlet, plug in and do not remove.

GUDINI, significant heating of the wires due to mutual induction.
The bay is wound with a bifilar cord, there is no special mutual induction there, just a dense packing of the cord with a concentration of heat and poor cooling.

Dmitry73, perversion.
How for anyone. For me, the perversion is to have permanent tees and extension cords instead of a sufficient number of outlets, especially immediately after repair.
I recommend to my customers to make so many outlets to do without tees and extension cords for the next 10 years. If you don’t know what will happen in 10 years - I recommend betting 2 times more than it is now. I read that in the West there are sockets every 2m around the perimeter of the rooms.

Electricity in itself is very dangerous. For electricians there is a PUE, for all other rules for the operation of electrical appliances (instructions for equipment).

FIRE REGULATIONS IN THE RUSSIAN FEDERATION of April 25, 2012 Clause 42.h) Forbidden: use temporary electrical wiring, as well as extension cords for powering electrical appliances not intended for emergency and other temporary work.

GUDINI, The heating of a wire twisted into a bay is not due to self-induction, but because of a decrease in heat transfer to the environment.

Extenders, if you buy, then only with built-in protection (AR + RCD), and it’s better to do it yourself.

Somehow, when you turn on the monitor and sewing machine in one extension cord, when testing it, the monitor protection "burned out" ..., and indeed, extra contacts ....

IN,
wire coil is an inductive reactance for alternating current, etc.

Alexander,
after that, doesn’t mean as a result of it .. Bad contacts I agree, but what does the extension cord have to do with it ??

PavelMB2,
firstly, the rules do not define what time means - a minute, 2 hours ... or the life of an individual :)

secondly, I think that the cross-section of the wires in the extension cords should not be less than 1.5 mm2 to supply a total peak load of 3 kW, sockets should be. with spring-loaded contacts and from normal metal, etc. ..

In general, how to produce unnecessary papers, it is necessary to produce products with guaranteed characteristics and educate people at school about the basics of electrical engineering

Extension cords in everyday life are evil! Each additional outlet when repairing wiring is a stock for the future. That is, when installing an additional outlet, you make a good supply, which in the future will allow you to use all the necessary household appliances.

Maksimcompletely agree with you. I want to add that the connection of each new outlet is most appropriate to a separate wiring line. As for the extension cords, their use to turn on household electrical appliances of relatively low power is justified. But if you need to turn on several powerful household electrical appliances, then you should use separate sockets. Conventional household sockets, rated at 16 A, as a rule do not withstand such a load for a long time. This is probably why most extension cords are made of wire with a cross-section of not more than 1.5 square meters. mm If you do it yourself, as they wrote in the comments above, carrying with a wire of 2.5-4 square meters. mm, where are you going to include it in everyday life? An ordinary socket can be damaged in a fairly short time when even 20 A flows through it. Unless for this carrying, put a special type of socket, for example, designed to turn on an electric stove. It seems to me that this is not right. I think that it is most advisable to abandon extension cords and tees to power several household electrical appliances and think about the need to fully or partially replace the wiring. And then provide for each electrical appliance a separate outlet.

But I figured where I have a computer, I need 8 sockets, who said that I need 2 times more than 16 ??))) what kind of battery is it then?
Comp, Monique, speakers, desk lamp, router, 2-3 charges for mobile devices, LCD TV, also close. And the total power can hardly reach 2 kW. Therefore, I will do 6 and I will not be steamed, you can also make a usb hub for mobile phones that will be powered from 1 outlet.
1.5kv section ??? wow where is this to find? The main thing here is to look at the thickness of the wire and quality. 6 cells in the extension cord are designed specifically for such weak consumers. Usually they are marked 16A or 3500 watts. therefore, a kettle and a telly or refrigerator, these are the maximum appliances with which it is better not to overdo it of course.For a short time, you can turn it on under 3000 watts, in this case I only “burned” the old socket, but nothing happened with the extension cord.
Another thing is that on the old wiring do not care where to turn on the kettle heater and washer, the load will be everywhere that will be heated in the most sensible place. By the way, who knows, does this drop voltage or current?

Michael, the total power of the electrical appliances you listed is unlikely to be more than 1 kW, respectively, the load current is small - about 5 A. In this case, you can limit yourself to installing one or two outlets and using a surge protector for 6-10 connectors. Separate sockets need to be installed for more powerful household electrical appliances, and for computer equipment, chargers, a TV, etc., the load current of each of which is no more than 1 A, it does not make sense to install separate sockets.

And when the load is turned on (increasing the load current on the wiring), a voltage drop is observed.

Hello!
Please explain
There is a single outlet, Schneider. It is connected with a NYM 2.5x3 cable (only phase and zero are connected, the earth is not connected), it is protected by an ABB 16A automatic machine, from the evening a disgraceful self-made extension cord was connected to the outlet, a heater (1500 W) was connected to the extension cord. In the morning it was discovered:
1. the heater plug is melted beyond recognition on the contact closure of the plug is not known (I could not see it, only according to eyewitnesses)
2. The extension cord socket is also fused, having disassembled it, the presence of contact closure was not found.
3. the line is energized, the machine did not turn off.
QUESTION: Why did the machine not turn off? :) Why did not the thermal release work? With poor contact, does the current gradually increase?
In order to debunk unnecessary disputes: the extension cord included an outsider.

banket13try to figure it out. The heater power is 1500 W, which means that the load current of this electric appliance 1500/220 is about 7 A. That is, with such a load, the thermal release of the 16 A circuit breaker should not work, since the load current is much less than the rated current of this machine. The heater plug and socket can be melted for several reasons. First: the plug sockets of the extension cord socket do not tightly clamp the inserted plug of the electrical appliance, in this case the heater, which leads to heating at the point of contact between the socket plates and the plug itself. When the load current flows for a long time, the heated metal parts begin to melt the extension housing and the plug of the electrical appliance.

The second reason is poor contact at the point of connection in the extension cord to the outlet of this extension cord. That is, in this case, due to poor contact, the elements of the socket and plug, which is currently plugged into the socket, will also heat up. Or it may be an unreliable contact in the plug of the heater itself.

The third reason is that the carrier used is not designed to include this load.

With poor contact, the current does not increase. Here the fact is that when the load current flows, a poor-quality contact connection will heat up. The higher the current, the higher the temperature of the contact connection will be and the faster this overheating will damage the socket and / or plug.

And the worse the contact, the faster when the load current flows, damage will occur at the site of this contact.

In order to avoid such situations, it is recommended to turn on the heater without using an extension cord, that is, directly to the outlet.

If you still can’t do without an extension cord, for example, due to the remoteness of the outlet from the heater’s starting point, then only high-quality extension cords that correspond to the declared load current should be used.

Usually poor-quality carrying, on which a rated current of 16 A is indicated, is unlikely to withstand even half of this value. That is, before you turn on the heater or other electrical appliance through the carrier, you must disassemble this carrier and make sure that it is designed to work at the current that will flow when you turn on a particular appliance. In this case, you need to pay attention to the cross-section of the carrying wire, to the design of the plug-in carrying clips, to the contact connections of the carrying wire with these clips. Very often in cheap Chinese carriers thin plates are used as plug clamps, which, firstly, do not withstand the declared rated load current, and secondly, do not provide reliable contact with the plug of the appliance, since they do not have rigidity, and after several starts / disconnections of the appliance, they are loosened and the rigidity of the contact of the plug with the carrying socket is reduced or not at all. That is, there is no reliable contact, and when the load current flows through this contact connection, it is damaged, as in your case.

It is best to assemble the carrier for the heater yourself: purchase a high-quality outlet for the required number of plug connectors and the required rated current, a wire of sufficient cross section and a plug that can withstand the load current that will flow through the carrier when the appliance is turned on.

Such cases often lead to fire, therefore, in addition to the circuit breaker, it is necessary to install a residual current device in the switchboard on this outlet (group of outlets). If the contact connection is broken (as in the case described by you), a current leak will occur, which may ultimately lead to a fire. If there is a leakage current, the residual current circuit breaker will de-energize this carrying, thereby preventing damage to it and then igniting it.

MaksimovM, Thank you very much for the detailed answer!

Hello, tell me please, I turn on the heater through a conventional extension cord with a pilot, the maximum current load is 10a. After a little work, the pilot button is disabled. You can take an extension cord with a current load of 16a, will this lead to a fire ????

I have a quadruple extension cord and are stuck in it: 2 laptops, computer speakers and the tablet periodically charges. Say it is dangerous?

In my apartment and in the country, the house is wooden, all the small loads are intentionally connected through line filters. No light load is directly plugged into the outlet. By small loads I mean laptops, televisions, pressure measuring instruments, chargers, faxes, multiplying equipment, printers, routers, gas boilers in a gas boiler, control devices, etc. I buy surge protectors, in fact this is the same extension cord with additional protective functions. with a short cord and with the selection of the necessary section.
Another conversation, if we are talking about loads with a power of 0.5 kW and above, they should be connected to sockets, and if through an extension cord, then only temporarily and in your presence. You came home, cool, turned on the electric heater through an extension cord, this is normal if it matches the cross-section and power of the outlet. Leave the house, unplug the extension cord from the outlet.
If you rearranged the furniture in the kitchen, moved household appliances to another place, then take the trouble to install new outlets and not plug them in through an extension cord, this is really fraught. Moreover, today such work does not require large expenditures and grooving the walls, wires can be dragged into the baseboards.
In general, I wanted to say that extension cords, surge protectors, tees, etc. things are useful and safe if used wisely.

Advantages of surge protectors over sockets:

-Protection against overvoltage, current protection (varistors + semblance of a machine for 10A).

They are equipped with a toggle switch - when leaving the house with one toggle switch, the entire supply chain is de-energized (the mechanism of conventional outlets is very frequent sticking / pulling out is not at all good). Let's say a voltage surge: the varistor in the network filter “closed”, the circuit breaker (network filter) worked - consumers quickly turned off, and did not fail. Example 2: a short circuit in a Chinese charger connected to a surge protector (for a friend, once even from the original charger, the plugs from the iPhone were broken once). The built-in automatic machine on 10A worked, disconnected. The 10A machine should work earlier than the switchboard at 16A, especially at 20A. Plus, the second machine in the networker is an additional safety net. If the surge protector is flooded with water, the RCD will work.

All of the above, of course, is suitable for small and medium-sized consumers. The wire 1.5 kW is rated for 3.5 kW, the rating of the machine in the surge protector is 10A (2.2 kW).

For some very common models of these machines, which some network filters are bundled with, the shutdown time during overload (in% of the nominal value) is as follows (from the table of characteristics):

150% - 1 hour,

200% - 3..12sec,

300% - 0.8..8sec,

500% - 0,3..2,8sec

1000% - 0.15..0.8sec

In an old tube TV, I cut a hole in the side wall and installed a double “internal” electrical outlet. It is perfectly attached to the “sheet” if the mounting tabs are deployed “vice versa”. The result was a TV + two power sockets. For an ancient computer and a tape recorder. Or for a table lamp and a soldering iron. ---------------------------- In the lower part of the telly, a LUMINUM radiator was installed, on which a 12 V 2 A power supply unit with protection against short circuit was bunged. This power led into the antenna jack. If necessary, a transistor television or transistor receiver was fed from the antenna jack in another room. (there was a TV signal and constant power in the antenna jack. They were separated by a drossel and capacitor and did not interfere with each other). I never turned off the power supply; its heating in any conceivable cases was minimal = the radiator is very wide).

Thank you for the article. Informative! :)

I have one extension cord for powerful appliances - washing machines, microwave ovens, slow cookers, coffee machines. Just because the location of the outlet in the kitchen does not allow everything to be put together, but I turn everything on strictly in turn and always control the temperature of the extension cable. It seems everything is fine, nothing is heating up.