The controls for enabling/disabling chiller are as follows:
The chiller is enabled when
TChi_CHWST > TChiSet + TDeaBan
The chiller is disabled when
TChi_CHWST ≤ TChiSet
where TChi_CHWST is chiller chilled water supply temperature, TChiSet is set temperature for chilled water leaving chiller, and TDeaBan is dead band to prevent short cycling.