The decisive factor is:\u00a0\u00a0<\/p>\n\n\n\n
- \n
- Heating:<\/strong> Any current flow generates heat \u2013 excessive temperatures damage the insulation.<\/li>\n\n\n\n
- Rated current vs. operating current:<\/strong> The rated current (e.g., 20 A) should not be confused with peak loads.<\/li>\n<\/ul>\n\n\n\n
Example: A 4 mm\u00b2 solar cable (e.g. KBE Solar DB+<\/a>) has a current carrying capacity of 57 A when laid freely.<\/p>\n\n\n\n
![\"Eine](\"https:\/\/www.kbe-elektrotechnik.com\/wp-content\/uploads\/2025\/05\/KBE-Elektrotechnik-Frau-vor-Photovoltaikfeld-1024x681.jpg\")
<\/figure>\n\n\n\nFactors influencing the current carrying capacity<\/h2>\n\n\n\n
There are many factors that influence current carrying capacity. These are essentially:<\/p>\n\n\n\n
Cross-section of the cable<\/h3>\n\n\n\n
The cable's cross-section is specified in mm\u00b2 and has an indirect, proportional effect on the resistance. This means: the larger the cross-section, the lower the resistance.<\/p>\n\n\n\n
Example: A solar cable with a cross-section of 6 mm\u00b2 has a higher current-carrying capacity than one with a 4 mm\u00b2 cross-section because the resistance is lower.<\/p>\n\n\n\n
As a rule of thumb: Doubling the cross-section \u2248 40% more current-carrying capacity<\/p>\n\n\n\n
Installation type<\/h3>\n\n\n\n
Installation depends on how well the heat generated is dissipated by the solar cables. If the heat is poorly dissipated, overheating can occur more quickly.<\/p>\n\n\n\n
Therefore, the poorer the heat dissipation, the lower the current carrying capacity.<\/p>\n\n\n\n
There are different ways solar cables can be installed:<\/p>\n\n\n\n
- \n
- Single cable laid freely in the air
\u2193<\/li>\n\n\n\n - Individual cable laid on surfaces
\u2193<\/li>\n\n\n\n - Two cables laid touching surfaces
\u2193<\/li>\n\n\n\n - Two cables laid in the cable shaft underground
\u2193<\/li>\n\n\n\n - Three cables laid underground in the cable shaft<\/li>\n<\/ul>\n\n\n\n
The current carrying capacity is greatest for solar cables that have been laid freely and becomes smaller the more \u201cconstricted\u201d the cable is \u2013 bundled cables heat each other up.<\/p>\n\n\n\n
Material in the cable<\/h3>\n\n\n\n
Different materials can be used for the solar cables.\u00a0<\/p>\n\n\n\n
- \n
- Copper:<\/strong> At approximately 56 MS\/m, it has a higher conductivity than aluminum (approx. 36 MS\/m) and carries electricity faster.<\/li>\n\n\n\n
- Aluminum:<\/strong> Is lighter and cheaper than copper. However, to achieve the same conductivity as copper, a larger cross-section is required.<\/li>\n<\/ul>\n\n\n\n
Ambient temperature<\/h3>\n\n\n\n
At high temperatures (e.g., on roofs), the current carrying capacity decreases. Therefore, PV cables must be UV-resistant and designed for temperatures between -40\u00a0\u00b0C and +90\u00a0\u00b0C.<\/strong><\/p>\n\n\n\n
Note:<\/strong> If the ambient temperature of your solar cable differs from that of the manufacturer, you must include a correction factor or conversion factor when calculating the current carrying capacity.<\/p>\n\n\n\n
Application of the standard IEC 60364-5-52<\/h2>\n\n\n\n
For the installation of multiple solar cables, conversion factors (=reduction factors) for the current carrying capacity according to IEC 60364-5-52<\/strong> must be used.<\/p>\n\n\n\n
When laying the cable underground, IEC 60364-5-52 Table B52-3 or B52-5, Column 7<\/strong>, must be used. The current carrying capacity values \u200b\u200bfrom Column 7 apply to the installation of the cable in a cable duct in the ground<\/strong>.<\/p>\n\n\n\n
The cables are buried directly in the ground in cable ducts with a diameter of at least 100 mm<\/strong>, made of plastic, earthenware, or metal<\/strong>. The soil must have a specific soil resistance of 2.5 K * m\/W<\/strong> and the installed cable duct must be 0.7 m deep<\/strong>.<\/p>\n\n\n\n
If the cable is laid directly in the ground, the current-carrying capacity according to IEC 60364-5-52 is approximately 10% higher than the values \u200b\u200bin column 7<\/strong>.<\/p>\n\n\n\n
Furthermore, IEC 60364-5-52<\/strong> must be used if the following deviations occur<\/strong>:<\/p>\n\n\n\n
- \n
- Ambient temperatures of the ground deviate from 20 \u00b0C<\/li>\n\n\n\n
- Thermal resistance of the soil deviate from 2.5 K\u2217m\/W<\/li>\n\n\n\n
- The number of loaded conductors\/circuits deviates<\/li>\n<\/ol>\n\n\n\n
![\"Eine](\"https:\/\/www.kbe-elektrotechnik.com\/wp-content\/uploads\/2025\/05\/KBE-Elektrotechnik-grosse-Photovoltaikanlage-schwimmend-1024x683.jpg\")
<\/figure>\n\n\n\nTips for selecting the right solar cable for optimal current carrying capacity<\/h2>\n\n\n\n
- \n
- The solar cable must be suitable for PV systems.<\/strong><\/li>\n<\/ol>\n\n\n\n
At KBE-Elektrotechnik you will find a wide range of solar cables<\/a> that have been specially designed for use in PV systems.<\/p>\n\n\n\n
- \n
- The solar cable must be certified.\u00a0<\/strong><\/li>\n<\/ol>\n\n\n\n
KBE-Elektrotechnik's solar cables are triple-certified<\/strong> according to the European standard EN 50618 (H1Z2Z2-K)<\/strong>, the international solar cable standard IEC 62930 (IEC 131)<\/strong>, and the standard 2Pfg 1169 \/10.2019 (PV 1500-K)<\/strong>. This guarantees excellent technical properties, high safety, and a long service life of at least 25 years.<\/p>\n\n\n\n
- \n
- Dimension the cable cross-section correctly<\/strong><\/li>\n<\/ol>\n\n\n\n
A solar cable with a cross-section of 6 mm\u00b2 releases less heat than a cable with 4 mm\u00b2 and the risk of overheating is reduced.<\/p>\n\n\n\n
- \n
- Use current carrying capacity tables<\/strong><\/li>\n<\/ol>\n\n\n\n
Here you will find the appropriate tables for determining the current carrying capacity of KBE Elektrotechnik solar cables.\u00a0<\/p>\n\n\n\n
- Use current carrying capacity tables<\/strong><\/li>\n<\/ol>\n\n\n\n
- Dimension the cable cross-section correctly<\/strong><\/li>\n<\/ol>\n\n\n\n
- The solar cable must be certified.\u00a0<\/strong><\/li>\n<\/ol>\n\n\n\n
- The solar cable must be suitable for PV systems.<\/strong><\/li>\n<\/ol>\n\n\n\n
- Aluminum:<\/strong> Is lighter and cheaper than copper. However, to achieve the same conductivity as copper, a larger cross-section is required.<\/li>\n<\/ul>\n\n\n\n
- Copper:<\/strong> At approximately 56 MS\/m, it has a higher conductivity than aluminum (approx. 36 MS\/m) and carries electricity faster.<\/li>\n\n\n\n
- Rated current vs. operating current:<\/strong> The rated current (e.g., 20 A) should not be confused with peak loads.<\/li>\n<\/ul>\n\n\n\n
![\"Eine](\"https:\/\/www.kbe-elektrotechnik.com\/wp-content\/uploads\/2025\/05\/KBE-Elektrotechnik-Stecker-Solarleitung-1024x683.jpg\")
<\/figure>\n\n\n\n