UPDATE to the post....
I added two more panels to my 24v system, 1500w (2s3p 320w/panel). The 4215AN is only drawing 1030w - 40A, the same as before with 4 panel. The difference is when is no sun. So, i think if you dont exceed 80v, the controller is running fine drawing only 1kw from a 1,5kw...