We're having surge problems with a 300 ton 19XR. I was told that the tower water needs to be reset according to load. We don't get actual demand as an input to the BAS system, so I'm using evap temp drop.
I've programmed the following reset:
3* (min) Evap Delta T = 65* tower water set point
12* (design) DT = 85* tower water temp set point
Does this sound like I'm on the right track?