The cables used in the low-voltage DC transmission part of the solar photovoltaic power generation system have different requirements for the connection of different components due to different use environments and technical requirements. The overall factors to be considered are: the insulation performance of the cable, heat resistance and flame retardant performance, Engage in aging performance and wire diameter specifications.
Specific requirements are as follows:
1. The connection cable between the solar cell module and the module is generally directly connected by the connection cable attached to the module junction box. When the length is not enough, a special extension cable can be used. Depending on the power of the components, this type of connecting cable has three specifications of 2.5mm, 4.0mm, and 6.0mm. This kind of connecting cable uses double-layer insulation sheath, which has excellent anti-ultraviolet, water, ozone, acid, salt erosion ability, excellent weather resistance and wear resistance.
2. For the connection cable between the battery and the inverter, it is required to use a multi-strand flexible wire that has passed the UL test, and connect it as close as possible. Choosing short, thick cables can reduce system losses, increase efficiency, and enhance reliability.
3. The connecting cable between the battery array and the controller or the DC junction box also requires the use of multi-strand flexible wires that have passed the UL test. The cross-sectional area specification is determined by the maximum output current of the square array.
The cross-sectional area of the DC cable at the name site is determined according to the following principles: The connecting cable between the solar cell modules and the modules, the connecting cable between the battery and the storage battery, and the connecting cable for the AC load. Generally, the rated current of the selected cable is the maximum continuous operation of each cable. 1.25 times of the current; the connection cable between the solar cell array and the square array, the connection cable between the battery (group) and the inverter, the rated current of the cable is generally selected to be 1.5 times the maximum continuous working current of each cable.