a

I don't know... In general, I do not like the idea of using a fuse between battery ground bus, and safety ground (which is what most systems do--Popping a fuse or circuit breaker when there is a short circuit is very anti-safety ground).

With the specific 600 volt input Schneider controller, I do not know how it is designed. Most solar charge controllers do not have an isolated input. The solar panel "ground"/negative is carried through to the battery bus side of the controller on most all other solar charge controllers.

What that means is that if there is a "ground fault short"--That the fault can be on the Vpanel wiring side, or it actually can also be on the DC Battery Bus side--And the controller can shutdown for either case. And while you are hunting down looking for a short between + or - on the Vpanel wiring side, there is actually a short on the DC + or - side of the wiring system (+ or - short to Safety/Green Wire grounding side).

Installing a fuse in the solar charge controller(s) allows up to 1 amp of current between the grounded array side (typically negative of the solar array is connected to safety ground through the controller ground fault detection fuse). If the fuse is conducting current (between 0 and 1 amp), everything is "Okay". If the fuse blows, then the controller "sees" a voltage difference between negative solar bus and safety ground), then the controller faults.

Another test (and frankly how I think all solar power systems should be wired)--Put a 6 AWG (or heavier) connection between the solar negative input terminal (assuming negative ground) and your green wire safety ground (your system ground rod/array frame-rack ground/etc.

The normal place to tie Safety Ground to DC ground is the negative ground bus of your battery negative bus bar--But since I do not know if the Solar charge controller is "transformer isolated" between Vpanel and Vbatt (you would ground the Vpanel negative to safety ground/chassis ground of the controller) or "not isolated" (you would normally connect battery bus negative to safety ground bus), you may need to try both.

You could try using your volt meter and measure from Vpanel negative to Vbatt negative and see if there is near zero volts (not isolated) or if you see a few volts or more difference (probably isolated from Vpanel to Vbatt).

When connecting the ground bond wire, just be careful. If you have a short between + or - and safety ground, it is possible you will get a good size spark (again you can use your volt meter to confirm... If near zero volts, should be no spark).

A good way to check for solar/battery negative to safety ground is to clip a filament light bulb between the two grounds first, and see if it lights up. Volt meters have very high input resistance and sometimes you get a "charge" between the two circuits (like charging a capacitor), and you really do not have a "solid connection". The light bulb can discharge that "static" like charge and give you a "better" reading of what is really happening.

-Bill