Hi,
I've got a building with 4 cooling towers and a big cooling load all year, including the winter.
I'm getting the following errors (Here for one week only, in january)
  ************* ** Warning ** CoolingTower:VariableSpeed "COOLING TOWER 1" Cooling tower water outlet temperature is below the specified minimum condenser loop temp error continues...
  ************* **  ~~~  **  This error occurred 909 total times;
  ************* **  ~~~  **  during Warmup 0 times;
  ************* **  ~~~  **  during Sizing 0 times.
  ************* **  ~~~  **  Max=5. Min=5.
  *************
  ************* ** Warning ** CoolingTower:VariableSpeed "COOLING TOWER 2" Cooling tower water outlet temperature is below the specified minimum condenser loop temp error continues...
  ************* **  ~~~  **  This error occurred 909 total times;
  ************* **  ~~~  **  during Warmup 0 times;
  ************* **  ~~~  **  during Sizing 0 times.
  ************* **  ~~~  **  Max=5. Min=5.
  *************
  ************* ** Warning ** CoolingTower:VariableSpeed "COOLING TOWER 3" Cooling tower water outlet temperature is below the specified minimum condenser loop temp error continues...
  ************* **  ~~~  **  This error occurred 909 total times;
  ************* **  ~~~  **  during Warmup 0 times;
  ************* **  ~~~  **  during Sizing 0 times.
  ************* **  ~~~  **  Max=5. Min=5.
  *************
  ************* ** Warning ** CoolingTower:VariableSpeed "COOLING TOWER 4" Cooling tower water outlet temperature is below the specified minimum condenser loop temp error continues...
  ************* **  ~~~  **  This error occurred 67 total times;
  ************* **  ~~~  **  during Warmup 0 times;
  ************* **  ~~~  **  during Sizing 0 times.
  ************* **  ~~~  **  Max=5. Min=5.
My minimum condenser loop temperature is 5C. I also have a basin heater set at 2°C. Here it seems that I'm getting all these warnings (they're only for one week in January...) without much cause since Max=5. and Min=5.
Can I discard them?
Also, I'm wondering if I shouldn't just turn off 1 or 2 CTs when outside temperature is below 5°C or something like that, so I'd be closer to the needed capacity. Does that make any sense to you?
If I were to do this, should I use the "PlantEquipmentOperation:OutdoorDryBulb" object or is there a better way to do it? I've tried doing it as follows and it made things worse, temperature was below setpoint 2671 times for each tower (which I don't even understand since I'm simulating 24*7*6=1008 timesteps...) :
CondenserEquipmentList,
   Chiller 1_TowerWaterSys Equipment List, !- Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 1 Object Type
   cooling tower 1,        !- Equipment 1 Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 2 Object Type
   cooling tower 2,        !- Equipment 2 Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 3 Object Type
   cooling tower 3,        !- Equipment 3 Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 4 Object Type
   cooling tower 4;        !- Equipment 4 Name
CondenserEquipmentList,
   Chiller 1_TowerWaterSys Equipment List 1-2 ON, !- Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 1 Object Type
   cooling tower 1,        !- Equipment 1 Name
   COOLINGTOWER:VARIABLESPEED, !- Equipment 2 Object Type
   cooling tower 2;        !- Equipment 2 Name
PlantEquipmentOperation:OutdoorDryBulb,
   CT two off below 10C,  !- Name
   -70,                    !- Dry-Bulb Temperature Range 1 Lower Limit {C}
   10,                     !- Dry-Bulb Temperature Range 1 Upper Limit {C}
   Chiller 1_TowerWaterSys Equipment List 1-2 ON, !- Range 1 Equipment List Name
   10,                     !- Dry-Bulb Temperature Range 2 Lower Limit {C}
   70,                     !- Dry-Bulb Temperature Range 2 Upper Limit {C}
   Chiller 1_TowerWaterSys Equipment List; !- Range 2 Equipment List Name
CondenserEquipmentOperationSchemes,
   Chiller 1_TowerWaterSys Loop Operation Scheme List, !- Name
   PlantEquipmentOperation:OutdoorDryBulb, !- Control Scheme 1 Object Type
   CT two off below 10C,  !- Control Scheme 1 Name
   PlantOnSched;           !- Control Scheme 1 Schedule Name