I have an odd problem any thoughts would be appreciated.
I have a set of screw compressors that have suction and discharge ports on the lines with a PV09AV Veris (0-10V) pressure sensor.
The pressure sensors are setup properly and I have used them many times before. The sensors on the suction side read a negative voltage when the screw compressors activate.
Anyone have any thoughts on why this would happen, the sensors are 0-10 volts and should not output a negative voltage however when I metered them I read -1.5 volts. The common to the sensors are grounded to the building steel along with the copper refrigerant lines.