Agree, PWM POT input is not actually isolated (pot ground and negative on PWM controller are connected when checking with multimeter) but couldn't find any schematics for the controller anywhere - even emailed DROK. Here is the link to the product page.
Still, connecting the insulated twisted pair wire properly remains the biggest question for me . The three wires inside seem straightforward but not sure what to do with the foil. I know foil should be connected on Arduino side only but does it connect to Arduino ground, or chassis (that is also ground for the high power side) or both?
P.S. Also, assuming that the POT input is actually linked to main circuit (even though everything else on Arduino is separated), should I just go ahead and connect negative terminals of the batteries across Arduino and high-voltage sides?
