Extension cord. It has been observed that the average buyer chooses a power extension cord based on the length and price of the cord. Another option is to choose based on the color and number of connections.
It is not right to choose an extension cord like this, because you do not think about its operational safety. Experienced electricians, on the other hand, look at completely different characteristics.
Extension cord, how to choose the right one?
The choice should be responsible, for very simple reasons, so that the house does not burn down later.
Another question may arise, why the price of outwardly identical extension cords differs several times. You will learn about this in this article.
The most important parameter of an extension cord is the size of the wire in the cable.
The cross-sectional area of the cable is measured in square millimeters. The more connection outlets in the extension cord, the larger the cross-section should be.
This is so that you can connect a powerful device to each socket, which you definitely have in your household.
Especially now, in winter conditions, when you want to warm yourself by an electric radiator, etc.
Of course, when connecting low-power devices, such as phone chargers, there will be no problems with a cable with a small cross-section, but when connecting several kettles or heaters, it will be dangerous.
Extension cords are usually equipped with wires with a cross-section of 0.5 mm², 0.75 mm², 1 mm², 1.5 mm², 2.5 mm².
The cross-section is indicated on the cable marking. A good extension cord with a 2.5 mm² cable can cost several times more than a similar one with a 0.5 mm² cable, since its main element, copper, is expensive.
Wire marking.
Sometimes manufacturers try to cheat and make thick insulation to give thin copper wires visual “reliability”.
Usually this can be observed in products made in China. The marking indicates a normal cross-section, but in reality it is not.
The real truth about a suspicious extension cord can be seen by disassembling the socket block. At the same time, you can check the quality of the soldering. You will immediately see bad contacts.
Of course, this does not mean that a “freshly” purchased extension cord should be torn apart. You can think about this if you have any doubts, but I will talk about it later in the article.
Power extension cord and problems.
Often, in order to save money, the soldering material, which should be made of tin, is replaced with a “diluted” soldering tin with the addition of lead, in which the tin content is half as much.
Such a soldering point has worse operational properties. It can be recognized by a dirty gray surface, not a silver mirror, as is usually the case with solder with tin.
Remember that an extension cord with such a soldering method is dangerous and should not be left unattended.
In mass production, low-tech soldering is often replaced by welding. However, such a welded (wire to contacts) extension cord will not be distinguished by a long service life.
Power extension cord and power.
Choose the size of the internal wire according to the workload. Cross-section depending on the power of electrical appliances:
1380 W – at least 0.75 mm²;
2300 W – at least 1 mm²;
3680 W – at least 1.5 mm².
It is better not to buy extension cords with a cable less than 1.5 mm², because people, not knowing this, can turn on a powerful heater in it and a fire may break out.
Extension cords can be with two and three-wire cores. The third wire is used for grounding.
Even if there is no grounding option at home, it is better to buy a three-wire extension cord. The marking indicates the number of cores, for example, 2×1.00 or 3×1.31.
Power extension cord, length.
The next important parameter is the length of the cable. To branch the socket, take short extension cords with a 0.5-2 meter cable.
For repairs, construction or in the countryside, long extension cords of 50 meters or more are often needed.
When using an extension cord, the cable can heat up.
The smaller the cross-section, the more the cable heats up. According to the regulations, the cable can heat up to a maximum of +65 degrees. If the wire is too warm – the cross-section of the wire is not enough for the selected load, it is better to avoid heating the cable.
If the cable is wound into a coil, the heat is not removed well and the insulation may melt. This will result in a short circuit. Therefore, when connecting powerful devices, you cannot leave the wire wound up.
It is advisable to unwind it from the coil so that it can give off excess heat to the environment.
Sockets break faster than cables.
A high-quality cable can last 10 years, of course, if the insulation on the cable is not damaged. The socket block with active use breaks down in 2-3 years.
If you notice melting, soot, heating or an extraneous sound when making a connection (crackling), it is time to replace the socket block.
Insulation.
For work in cold or hot conditions, ordinary PVC insulation for wires is not suitable.
In the cold, it can crack, because it remains hard, but in the heat it becomes very soft.
For such cases, extension cords with rubber insulation are produced. Of course, this will cost much more, but it will be safer.
Moisture protection.
When working in repair, construction conditions, in the countryside, an extension cord with moisture protection is useful.
Covers on the contacts of the extension cord protect the sockets from small accidental splashes.
Wires button and short circuit protection.
For convenience, manufacturers add a switch to the socket block. You can leave and turn off all devices with one button.
If you do not plan to use it, it is better to buy an extension cord without a switch. This is an additional weak link that often fails.
Bad soldering and a melted switch. Manufacturers can install a fuse in the extension cord, which turns off if the power of the applied current is exceeded.
Usually this protection is made of a bimetallic strip and works quite slowly. In the event of a short circuit, the devices in the electrical panel (fuse block for the whole house) will operate faster.
If the cross-section of the extension cord is comparable to the cross-section of the electrical wires in the apartment, a common fuse block is sufficient.
Network filters.
A surge protector is an extension cord with a node installed in the socket block, which can be called a filter.
Almost every switching power supply has such a filter, so city dwellers do not need to buy a surge protector.
It can only be useful in the countryside or in an individual home version.
Adapters.
Plugs often do not match the installed sockets, and devices are connected using cheap Chinese adapters.
As a rule, they have poor-quality contacts, they heat up and melt.
It is especially dangerous to connect powerful devices through an adapter: kettles, heaters, microwave ovens.
If you have a device with a non-standard plug, replace it with a standard one.
Good day!
