Sunpower P3 UPP 480 Wp

[Bendesa1962]

Hi all,

I've a question about this Sunpower Panel. It's the P3 UPP 480 Wp. I've not installed Sunpower before. I see there are 3 junction boxes on the back off the panel.

The two on the left and right side are plus and minus I assume. What about the middle one? I assume I can use it also to make a better cable management but is it a plus or a minus or?

See attachment for the picture

Kind regards

[oregon_phil]

Each box contains a bypass diode per spec sheet.

Junction Box IP-67, Renhe ZJRH 05-8 or Zerun Z4S or Stäubli Evo2, 3 bypass diodes

It's probably the same reason half cut solar cell modules use split junction boxes.

Split junction box

One of the differentiating factors of a half cut solar cell modules is ‘dual’ or split junction box. In this type of junction box configuration, the function of the standard solar panel junction box is split into three different boxes, with an internal string and bypass diode in each.

A split junction box leads to lesser metallization than a standard panel in comparison to poly or mono panels and creates lesser internal resistance which saves space. The space saved as a result of this configuration helps create more space between cells, thereby increasing internal reflection of light from the back sheet into cell surface, which increases efficiency of the panel.