Engineering notes
Chilled-water pipe pressure sensors
Choose a chilled-water pressure sensor: bar range, 0–10 V or 4–20 mA, tap location.
Building chilled water is a few bar, not a process line. A 16 bar head on a 4 bar loop wastes the analog span — the DDC sees a sliver of the range. A 2.5 bar head on a 6 bar loop pins at full scale and the pressure valve hunts. “Water sensor” on a take-off is not a model.
Read working and test pressure on the schematic. Match 0–10 V or 4–20 mA to the controller. Thread or flange, chilled water not oil. The tap sits before or after the pump as the file draws it — not on a tight elbow where the reading is noise.