Can someone clarify this from my "Smart Solar" charger?
3.2 Grounding ● Battery grounding: the charger can be installed in a positive or negative grounded system. Note: apply a single ground connection (preferably close to the battery) to prevent malfunctioning of the system. ● Chassis grounding: A separate earth path for the chassis ground is permitted because it is isolated from the positive and negative terminal. ● The USA National Electrical Code (NEC) requires the use of an external ground fault protection device (GFPD). These MPPT chargers do not have internal ground fault protection. The system electrical negative should be bonded through a GFPD to earth ground at one (and only one) location. ● The charger must not be connected with grounded PV arrays (one ground connection only) ● The plus and minus of the PV array should not be grounded. Ground the frame of the PV panels to reduce the impact of lightning. WARNING: WHEN A GROUND FAULT IS INDICATED, BATTERY TERMINALS AND CONNECTED CIRCUITS MAY BE UNGROUNDED AND HAZARDOUS.
I am installing my smart solar into a battery box. Does this mean I can wire the grounding screw on the solar charger to a positive block. Is there a minimum gauge wire I need for this? I was about to use a 10 gauge but would not mind something smaller.
Does it need a Ground fault protected? How is this done?
There are two things often referred to as "grounds" - creates a lot of confusion. One is the negative power wire, the other is a grounding lug on the chassis of the device.
Better to think in terms of pos/neg/ground.
You connect solar pos/neg to the controller, and connect controller pos/neg to the battery. That is what is meant by "battery grounding".
IF you were installing the setup on a building, you would also have an extra safety wire connecting the metal frames on the solar and the ground lug of the controller to the planet via driven ground rod or cold water pipe or both. That is what is meant by "chassis grounding".
But you don't need the chassis grounding on a portable or vehicle mounted system. It's not tied to the planet anyway. In a big complex setup like a yacht you might want to tie all the metal together, but you don't need it on a camper.
The NEC requirement for a GFCI on the solar/battery side is primarily for systems on a building where the solar might be rigged into 600v strings. Again, not needed on a camper.
Note that a GFCI on the output of an inverter is still a good idea.