I have a 3 wire system well pump (red, black, yellow wires to pump) that has a Red Jacket control box and a Square D pressure sensor. Currently the pressure sensor is wired to the primary load center for the house (a 15 Amp 240v breaker). At this primary load center, the neutral and ground share the same bus bar. I want to connect the Square D pressure sensor to a sub-panel that has separate neutral and ground bus bars (the sub panel has been installed for years and is code compliant). I assume the pressure switch "ground" should be connected to the ground bus bar and not the neutral in the sub panel, but want to be sure.