When wiring three or more solar panels in parallel, it is advisable to install a 10 or 15 amp inline fuse on the positive wire of each panel. Should one panel fail or short out, that panel's fuse would blow and prevent the power from the other panels from entering the shorted panel thus preventing excessive heating of the shorted panel and prevent the other panels from failing due to excessive current. This can be accomplished easily using an MC4 inline fuse holder plugged into an MC4 T-branch. These fuse holders are available on Amazon or other website. Below is a wiring diagram illustrating such an installation.
Thomas Trimmer has been cruising with his Ericson 38 sailboat on the Great Lakes for over 20 years. He has pioneered the use of solar energy for wilderness cruising. He is continually designing and building equipment to simplify and enhance the cruising experience.