How To Tell Which Wire Is Positive Solar Panel

With parallel solar panels the positive terminal from one panel is connected to the positive terminal of another panel and the negative terminals of the two panels are connected together.

How to tell which wire is positive solar panel.

When stringing in series the wire from the positive terminal of one solar panel is connected to the negative terminal of the next panel and so on. Connect the negative wires together in the same fashion and the wires off the last panel in the parallel circuit are connected to the battery. When stringing panels in series each panel additional adds to the total voltage v of the string but the current i in the string remains the same. Wiring solar panels in parallel causes the amperage to increase but the voltage remains the same.

A simple voltage reading will show you the polarity of a solar panel even when inside. Set the volt meter to read dc volts. Actually there is a color code standard for dc pv systems and as the nec code book does not specify ac or dc the color code applies equally to both such systems. There is no color code standard for solar pv panels like there is for ac systems.

Extend the output wires of the solar panel the positive wire of the solar panel is terminated with an mc4 female connector marked. Only your volt meter will tell you the truth. To measure across the solar panel terminals or wires put the red positive meter lead on one side and the black negative on the other. The bare end of the positive extension wire will now be of positive polarity.

Connect this cable to the mc4 male adaptor.