Solar Panel Junction Box

I received a junction box with some solar cells and I wondered how to wire it up with the diodes in between each terminal strip.

Category:

Howto & Style

Tags:

• Green
• Free Energy
• Solar
• DIY Solar
• Homemade Solar Panels
• DIY Solar Panels
• Solar Junction Box

[laehcim8544]

sorry should have said when panels are wired in series connect panels in parallel with diodes, +ve of panel to -ve of diode and -ve of panel to+ve of diode for each panel in the series, the other single diode is a blocking diode

[shartne]

@laehcim8544 OK, thanks I will refer to this when I hook it up.

[BigAlxr7007]

If you knuw of someone who has a manufacture panel have the remove the back plate off . small flat blade scewdriver will do the trick and it will show you exactly how the wiring is.

[shartne]

@BigAlxr7007 I found out that the far left and right are going to be positve and neg you dont have to use the middle ones they are for giant panels that have 72 cells and more. It helps when shad is on part of the panel but never mind that just I ll just use the two outer ones pos and neg how i see fit.

[electrodacus]

They are bypass diodes and from what I see the box is for 3 solar panel connected in series each panel will have a diode in parallel the silver sign on diodes go to positive terminal of the solar panels.

But I think you do not have a 36V installation.

Most brand solar panels have two bypass diode as if you remove the diode in the middle and connect the two middle terminals together terminal on the right go to positive left negative and the middle one to a third wire 18 cell for each diode.

[shartne]

@electrodacus thank you for your information.

[laehcim8544]

The diodes in the block are by-pass diodes where panels are connected in parallel to stop current flowing from one panel into the other if you have shading of any panel connected to the block.

[MrShaman143]

lol me too

[shartne]

@SolarInfoWarrior you are correct but this box is made for a different type of set up. Its not the normal kind. Its for having different parts of a solar panel make voltage even when another part is shaded. I guess a huge panels with 72 or hundred cells in it.

[shartne]

@Fearlessthinker ok thanks I may opt for the outer ones sounds the easiest. i don't have any shade.

[Fearlessthinker]

That junction box is set up for panels with 3 strings of cells. The strings would use T1- and T2, T2 and T3, and T3 and T4+. The diodes allow the current from unshaded strings to flow so the panel's output is not choked by the shaded string(s). For 1 long string of cells, like you usually make, use the outer terminals (T1- and T4+). If you leave the diodes in, then this panel can be part of a string of panels and will not choke the string's current flow if itself is shaded.