When making an extension cord, it is better to adhere to generally accepted standards. For powerful technology plug non-separable. Let us analyze in order, we will bring in a couple of fresh ideas about making reliable connections with our own hands: how to choose a cable, where to borrow an outlet. As a result, we hope - readers will understand how to make an extension cord on their own.
Choosing an Extension Cable
The first question that is on the agenda. Need a cable. Think about why we decide to make an extension cord of the power supply network:
- Firstly, it’s impossible to buy an extension cord according to the required parameters. More often it is the cable length.
- Secondly, a special extension is convenient to measure the power of household appliances( 220 volts, 380 volts) with the help of current tongs. It is required that the conductors of the area selected for measurements go separately. In this case, it becomes possible to measure the magnetic field level of the conductor( going together create interpolation, making the process impossible).
- Sometimes an extension cord is used with a fixed outlet. Curiously, no documents regulate the minimum height. It is allowed to put sockets on the plinth.
At the choice of the cable of the extension cable, the EIR states the facts and regulations.
Combining of zero protective and working conductors is impossible
It is not allowed for portable consumers to combine zero protective, working conductors. Do not ground terminal to zero. Although there is no ban on fixed sockets. We believe is associated with protection.
Sockets intended for switching on equipment used in outdoor conditions are protected by a differential circuit breaker. Note - do not know in advance the scope of the extension cord. At the same time, the combination of protective and neutral conductors violates the principle of operation. As a result, a person working on the street may kill earlier than overcurrent protection will work.
cable For the above reason, it is reasonable to equip an extension cord with a cable for three cores. Otherwise, the operating conditions of most of the equipment are clearly violated. And an electric tool? Grounding terminals are deprived, regulations on which to do is prohibited are issued. The electric tool according to the mentioned norms is equipped with reinforced insulation( second safety class II), work quietly in damp rooms, on snow provided: the extension is solidly insulated. At a minimum, there are curtains on the sockets, a cheap outlet will not go, you will have to break the element( sticks).
Sockets and plugs
Probably, you still use the equipment of the USSR.Old plugs do not always fit European outlets. I do not want to disfigure an inceptive connector, let's use a loophole: it is permissible to use regular sockets with grounding on the base. As a result, a universal device appears, which is permissible to work with in any conditions. Take the extension with the necessary elements.
Extension cable cross-section
For household electrical receivers, according to PUE, cross-section of not less than 0.75 square millimeters of copper. Pay attention to the photo. The cable section H05VV-F of a typical extension cord is visible.3G means the presence of three veins, next to it is written a copper section - 1 square millimeter. Extender meets the requirements of the EMP.For industrial copper receivers 1.5 square millimeters.
In practice, the section is selected with a large margin, guided by needs. Characteristics of the cable H05VV-F are standardized by GOST IEC 60227-5.From the link to GOST 22483, we find out the correspondence between the AWG gauges, the cross-section of copper, will allow ordering on Aliexpress. It is easy to notice that there are no tables for maximum currents, similar information is provided by the old version of OLC( sixth edition).We do not think that the change of legislation caused damage to the laws of nature, we boldly recommend numbers to readers. From table 1.3.4, we find out that for cables with PVC insulation, a copper core of 0.75 square millimeter, the permissible current is 15 A. Translated into a power of 230 x 15 = 3.45 kW.
It is not proposed to include a welding machine in the extension cord. Consequently, it is better not to use the minimum copper cross section, take it with a margin. The extension cord is equipped with several sockets. It becomes possible to work simultaneously with two or more devices, it is difficult to take into account the actual power consumption. At maximum current, welding machines, for example, demonstrate operating cycle parameters characterized by duration of rest and activity.
Among other things, regarding the choice of the cross section of the cores, please note: in three-phase circuits, it is allowed to use a wire where the zero( working, protective) conductor is thinner than the others. The OLC permits the use of cables until legislation is changed with an explicit prohibition to do. In other cases, the thickness of the neutral conductor is not thinner than the phase.
Please note: high-class cores of flexibility. The extension cord is not considered stationary equipment, presumably, will have to use in a variety of conditions. The veins should not break with endless changes of position.
Achieved by design features. First of all, a set of sections with many small wires. It is possible to read in detail GOST 22483. Why? PUE says: the connection of low-grade conductors( single-wire) is allowed under the screw of only fixed installations. The rule indirectly says: in the case of an extension cord, use another cable.
The higher the flexibility class, the better. When ordering wire PV, PVA, pay attention to the factor. The class of the core fits in the range of 2 - 4. It is clear that it is better to take the latter. Less chances of breaking the vein by frequent bending( class sets the minimum radius).
Additional requirements are made for lighting installation devices and power outlets. Concerns protective contacts. The protective contact of the socket is called the pin, which forms a triangle with the sockets, which does not allow the device to be turned on in the wrong way. Electrically, this part is reliably grounded.
As a result, we know the location of the phase. Therefore, we will provide a break with a switch located on the wire. Protection is provided against the release of phase to the cartridge when necessary. Visible on European sockets - grounding contact.
Pay attention: the plug of the majority of powerful household appliances is supplied with a deep opening under protective contact. Although the technique does not apply to lighting. The manufacturer realizes the versatility of hassle equipment connectors.
Restrictions on the use of electrical extension cords
Regulatory documents give a narrow number of restrictions on the use of extension cords. Without special protection measures, it is not allowed to operate engines with a capacity exceeding 1 kW( without specifying the type: asynchronous, collector).We will bypass the condition in only one case: it is necessary to make the disconnection / activation of the contact possible only when the equipment is turned off. Apparently, here arcing is assumed, with a sharp break or switching circuit.
A typical extension cord is not suitable for measuring with a clamp meter. An example is a photo. Isolation of the supply wire is broken, it is permissible to measure with current clamp. The photo is not able to serve as an example of how to make an ideal type extension cord yourself. In our case, a two-core wire was used, no more was needed, the socket was taken of the old type, where the plugs with diameters of plugs made according to the European standard are included in the socket diameter. Helps to avoid connection difficulties.
I wanted to add here a not so obvious fact, it is unequivocally easy to follow in practice: the plug of the extension cord stands as it should be. Holding the wire, you can detect: the phase is always on the side that is in the outlet. Look at the photo, demonstrated: the plug is located in the most obvious way, the wire down. Phase in left position shown. Helps electricians, craftsmen stop guessing. Phase to the left.
Symmetrical plug has no pronounced direction. Recess under the protective contact is located on top. As for prefabricated forks, where there is none, you need to be guided by inscriptions( see photo) in order to be read, not to be positioned upside down. We emphasize that in this case everything depends on how we connect the wiring inside the extension cord. It is necessary to make that at the specified location of the plug the phase coincides with the socket in the extension cord( if you take the image shown in the photo).At first glance, the extra complexity in the work situation is useful for different purposes.
Please note: for high-power devices, the plug is non-separable. In search of a cable of such length that corresponds to a given condition, let's go to a deceptive maneuver:
- Carefully seal the wire according to the instructions.
- Take the filler coupling compound, pour it inside. After solidification, the cooling conditions will deteriorate a little, but a reliable framework for maintaining the shape is formed. In other words, the fork after such manipulations becomes nonseparable.
Varieties of extenders
We do not see any work with our own hands to make an extension for headphones. Today, there are plenty of collapsible USB connectors on the market; we will get a four-core copper cable anywhere in the world( using Aliexpress).The power lines go sideways: you can see that they are pushed forward to avoid loss of information when the contacts open. Inside pass on two wires data. It is better to take the cable without connections, in one piece, the attenuation of a weak signal will be minimal. We consider to get a shielded cable as an excellent option: certainly, it will increase the communication range.
Twisted pair suitable for USB.Frequencies will be somewhat different, at small distances imperceptibly. You can make a modem extension with crimping pliers. The photos shown are taken in DNS, suitable for 8 and 6-position connectors( suitable for telephone operators).
Finally, no problems with audio jack connectors. Probably noticed: on the front panel of the system unit sometimes goes mono. .. Bite your elbows? Just look inside, make the correct wiring of the board, having installed the necessary jumpers, stretch the cable with the required number of wires to the motherboard. The whole secret: just some manufacturers are too lazy to do, they are pushing cheap stuff. We believe that now every reader has understood how to make a USB extension cable yourself, the goal of the review has been achieved.
We say goodbye, we believe, this knowledge will really come in handy in practice, when once again you need to make an extension with your own hands.