The solar J-box, short for junction box, mainly consists of box body, box cover, terminal block, diode, connecting wire and connector. It is usually used to connect and protect wire. With application of solar technology, the solar junction box is gradually put into use and it plays an important role in the solar battery packs. It can make electricity produced by solar battery easily transmitted to external circuitry. Meanwhile, it has a protective effect to solar battery packs. Currently, there are various kinds of J-boxed in the market. As J-boxes are so important to components, to choose a proper J-box is of great importance. To help to choose a suitable J-box, the following text analyzes advantages and disadvantages of several types of J-boxes.
1. PV junction box
The PV junction box is an important part of solar battery packs. Generally, it contains three types that are traditional type, sealing compact type and glass curtain wall special type. The traditional PV junction box has clamped connection, fast operation and convenient repair. But as it is equipped with the electrical terminal, it has large volume and bad heat radiation. Holes on the cable will reduce its water resistance. Moreover, it has small conductive area and unreliable connection. On the contrary, as the sealing compact PV junction box applies metal terminal soldering, it has small volume, better radiation and reliability. Its irrigation sealing makes it possess water and dust resistance. But its repair is very inconvenient. Similarly, the glass curtain wall special type also applies sealing design. Its heat conductivity, reliability and water resistance are good as well. However, as it applies soldering joint, when the cable conductor enters into the box through two sides of cable entry, it is troublesome to solder it on the metal terminal in the long and narrow box.
2. BIPV junction box
The BIPV junction box is the abbreviation of building integrated photovoltaic junction box. Such a junction box has thin-slime appearance, stable performance and easy installation. It provides users with a practical and economical solution. It can be widely used in BIPF solar panels. But it has relatively high requirements on various aspects. E.g., it has different requirements on glass mechanical properties in different construction, while the requirements of other common junction boxes are the same in different construction. In addition, in the application of BIPV Junction Box, requirements on heat and noise insulation, indoor daylighting and service life of solar power system should also be taken into consideration.
3. Silicon junction box
Silicon junction boxes have strong aging and UV resistance, reliability and excellent weather resistance and conductivity. In various kinds of severe conditions, it still keeps excellent breakdown resistance. During outdoor use, it isn't affected by UV light, ozone, water, acid and basic. However, once faults emerge, it is difficult to repair.