An illiterate signal or power cable can not only degrade the characteristics of the device connected to it, but also quickly fail or even cause a fire. The industry produces several hundred varieties of cords, differing from each other in design and technical characteristics.
Instructions
Step 1
All cords, regardless of purpose, are divided into single-core and multi-core. We are not talking about the number of conductors in the cable, but about the number of cores in one conductor. A stranded conductor can handle multiple bends well, although it should not be abused on purpose. Connect devices that are moved during operation using only such cords. Single-core cables are good for connecting fixed wiring products. It is not recommended to use single-core aluminum cables instead of copper ones. Stranded aluminum cables do not exist.
Step 2
Some devices move almost continuously during operation. These include, in particular, electric shavers and handsets, and in industry - manipulators. They are attached with twisted cords. They are stranded, and at the same time they themselves are coiled like a spring.
Step 3
Devices whose external elements of the structure heat up during operation, connect with heat-resistant cords. In such a cable, the insulation is made not of PVC, but of rubber, and on top of it there is a fabric sheath. But it is impossible to use such a cable unnecessarily (together with devices whose outer surfaces do not heat up): its quality is low, since the rubber insulation hardens and crumbles over time. If you notice the slightest sign of this, replace the cord immediately, otherwise a short circuit may occur.
Step 4
If a signal with a frequency from hundreds of hertz to several tens of megahertz is transmitted over the cable, it must be twisted or shielded. The former are most often used to transmit digital data, while the latter are used to exchange analog signals. Coaxial cables are used for signal frequencies up to several gigahertz.
Step 5
Flat cables, in which the conductors are arranged in one row, are called stubs. They are found on computers that have old IDE hard drives and floppy disk drives. More modern cables, where the conductors themselves are flat (like on a printed circuit board), can be found in mobile phones. If the device is sliding or folding, the ribbon must be replaced as it wears out.
Step 6
Always choose the right cable for two parameters: cross-section and operating voltage of insulation. Select the first one according to the tables depending on the material of the conductor and the current strength. Remember that in a stranded conductor, the cross-sections are to be added, not the diameters of the conductors. The second must be obviously (with a margin of at least 2) lower than the voltage between the conductors and between each of them and the ground. Perform any work on connecting and disconnecting the cords when they are de-energized, unless otherwise specifically stated in the documentation.
