I have two 290 watt panels in series that are currently used to charge a 48V battery bank via a MPPT charge controller. The run from the panels to the charge controller and batteries is about 70', and I've got a PV-direct load (one or more DC fans) I'd like to run that is 30' in the opposite direction. I know the output voltage from the panels will vary widely, but assuming the PV-direct load (i.e. fan(s)) is able to handle that range is it possible for me to tie in to the existing +/- outputs from the panels (combined, something like 75V max) and run that over directly to a DC load (in addition to the run to the charge controller)?
My primary concern/question is how this might affect the charge controller (a Victron SmartSolar MPPT 150/35). I think the draw from the fan(s) would be quite low in proportion to the "power" of the panels, so would it just be that the charge controller would only "see" / experience a reduced voltage level coming in from the panels (e.g. what might otherwise be a strong 75V might only come through as 60V due to PV-direct load burning-down some of that potential energy)?
Is this kind of setup "allowable" / advisable? i.e. having a PV-direct load in addition to a MPPT charge controller "load", each on separate circuits. Would the PV-direct load side need its own ground connection? BTW, I know the PV-direct load circuit probably can't be as simple as depicted below; for example at the least there would probably be a voltage monitoring relay ensuring the fan can only kick in above some set voltage and also a thermostat.
Thanks in advance!