I have an off grid Cabin with SP6548 (all in one ) with 8- 500w solar panels mounted on wood frames on the ground . When I touch the frame of my solar panel, I get a shock. I can feel the current running through it. It seems very low, but it’s enough to lightly tighten my muscles. Do I need to ground the solar panels to the main ground or what would I need to do to eliminate this?