This method is suitable for wires of standard cross-section. For example, you have already determin the diameter using one of the above methods. Then you use the table to determine the cross-section.
Table 1: Definition of cross-section by wire diamete
For example, if your diameter is 1.8 mm, this means that the cross-section according to the table will be equal to 2.5 mm2.
By power or current
If the conductivity of the core is known, then it can be us to gcash data the cross-section. To do this, you will ne one of the parameters of the conductive core – current or power. You can also do this if you can calculate the load. After that, you ne to select the appropriate option from the tables below. But it is necessary to take into account whether the wire is made of aluminum or copper cores.
Table 2: for selecting the cross-section of copper wire, depending on the current consumption
For example, if when installing aluminum wiring you know that the maximum current that the wire can pass under continuous load is 21 A, then to select the cross-section you ne to look at the line above – 4 mm2.
Calculation of the cross-section of a multi-core wire
If a multi-core wire is us, in which all the conductors are identical, the total cross-section is determin by adding up the area of all. For example, the size of one core is measur using any of the above methods. After which the actual cross-section is determin by the formula So = n × Si, where
- So is the total cross-section of the entire conductor;
- n – number of conductors of the same diameter;
- Si – cross-section of one wire.
Calculating cable cross-section using online calculators
Advice from an electrician
If you are selecting a VVGNG wire or cable to power an example of neuro’s response in yandex search results network, pay attention to the following points:
- Look at the color of the copper and aluminum wire, as the manufacturer could save money and use an alloy, which significantly increases electrical resistance and does not allow the italy numbers of permissible loads on the cross-section.
- No matter how thin the insulation of a flexible cable is, to calculate the cross-section you still ne to measure only the core. Since extra millimeters will allow you to use a wire with a smaller cross-section to power an excessive load, and this is fraught with damage.
- If at some stage you doubt the sufficiency of the cross-section or understand that it will not be possible to use devices of lower power, it is better to install the wiring with a thicker wire.
How to determine the compliance of parameters?
As a rule, such incidents during purchase can be avoid by being extremely attentive on your part:
- A normal cable must have its marking, which provides the buyer with all the information about the model, operating features, parameters. In case of encountering questionable products, you may find that the data about the product is not present in full or is completely absent.
- If the conductor is really good, it must be provid with quality certificates. Technical documentation indicates that it is not only manufactur in accordance with regulatory documents, but has also pass the appropriate tests.
- A good wire cannot cost a penny – since the price of materials is quite high, cheapness should make you think about whether there is some kind of catch in it. If you wish, you can come to the store with a micrometer or caliper and perform a check to dispel doubts.
Detail AWG table for solid and strand cables and conversion formula
You are right, our answer to question 119 provides only the most common conductor sizes, typical for voice and data networks, as well as for the most common foreign automat building management systems. Other sizes are ne less often, and most likely not in an office environment, but for sound recording and playback systems. But since this topic has been rais, we are publishing more complete conversion tables accurate to the third decimal place, and most importantly, we provide a formula by which you can always go from AWG to millimeters for single-core cables even without tables. For obvious reasons, we are not publishing the formula for converting from diameter to cross-section in sq. mm :).
Single core conductors
The formula for converting AWG to millimeters for single-core cables is as follows:
The multiplier 0.127 is exactly 0.005 inches. When AWG gauges were develop, 0.005 inches, the thinnest wire size at the time, was adopt as AWG 36, and 0.46 inches, the thickest gauge at the time, was adopt as AWG 0000. When a gauge designation has multiple zeros, it means the wire is thicker than AWG 0. For convenience, 0000 is often replac by 4/0, 000 by 3/0, etc.
The ratio between the thicknesses chosen as boundaries is 92 times, and this range accommodat another 38 calibers, and they were creat in such a way that the ratio between adjacent calibers was a constant value (the root of the 39th degree of 92 is approximately 1.1229322, this is the ratio between adjacent calibers). Now it is clear where the values 36 and 39 in the exponent came from.
For thick gauges, designat m/0, the negative value -(m-1) is taken as the AWG value. For 4/0 cable, this will be -3, for 3/0 cable, the value -2, etc.
