I have two large air handlers that share a common duct system. Supply Fan vfd's maintain a static pressure in the supply duct. Each machine has its own separate pressure transducer. Because it is impossible to calibrate these absolutely perfectly, the ahu that reads the lesser amount of pressure ramps up. This causes the other to ramp down because it begins sensing a higher than setpoint pressure. It continues like this until the one unit gets to minimum rpm and then the other ahu ramps up and does all the work. I need a 0-10 vdc repeater with energy isolating characteristics so I can run both ahu's on the same transducer without sharing any power between controllers. Anyone know a part number that fits that bill?
