Solar Panel Wiring

In the "old days" solar panels had junction boxes on the back, and installers had to use flexible conduits or UV-resistant wire to connect the panels together. While a few solar panel models still use junction boxes, the vast majority of modern solar modules have a sealed junction box with positive and negative "pigtail wires" that terminate in special snap-lock connectors. This allows panels to be easily connected together in series-strings of two or more, which speeds installation and nicely compliments other components in the system.

At some point however, those series-strings have to be connected to a combiner box (an electrical enclosure with circuit breakers). A special UV-resistant extension cable with weatherproof snap-lock connectors is used for this task. There are several styles of snap-lock connectors in common use, and it's important to choose the right connector to match your solar panel (MC3, MC4, Tyco, Radox, etc). The usual procedure is to cut the extension cable near the middle, using the appropriate end (male or female) to mate with the solar panel or string. A 30-foot cable is sufficient for most installations, usually one cable for each panel or string of solar panels. Check the products here to find the correct cable for your needs.

National Electric Code requires grounding of solar panel frames for safety. Check out our related products for grounding lugs, lightning arrestors, and other products to complete your array installation.