Daikin WDC Installation, Operation And Maintenance Manual page 49

Table 15: Tower Setpoint Settings
Description
Valve Position (Bypass) 100%
Valve Control Slope Gain 1
Valve Control Error Gain 20
Valve Control Range (Max) 100%
Valve Control Range (Min) 10%
Temp–Max. Start Position 90 °F
Maximum Start Position 100%
Temp – Min. Start Position 60 °F
Minimum Start Position 10%
Valve Deadband (Lift) 1.0 psi
Valve Deadband (Temp) 1.0 °F
Valve Target (Lift) 30 psi
Valve Target (Temp) 65 °F
VFD Stage Down @ 20%
VFD Stage Up @ 80%
Cooling Tower Control None
Tower Valve/Fan VFD
None
Strategy
Tower Valve Type NC (To Tower)
Cooling Tower Stages 2
Fan Stage Up Time 2 min
Fan Stage Down Time 5 min
Stage #4 On (Lift) 65 psi
Stage #3 On (Lift) 55 psi
Stage #2 On (Lift) 45 psi
Stage #1 On (Lift) 35 psi
Stage Differential (Lift) 6.0 psi
Stage #4 On (Temp) 85 °F
Stage #3 On (Temp) 80 °F
Stage #2 On (Temp) 75 °F
Stage #1 On (Temp) 70 °F
Stage Differential (Temp) 3.0 °F
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Default Range
0 to 99
0 to 99
0 to 100%
0 to 100%
0 to 100 °F
0 to 100%
0 to 100 °F
0 to 100%
0 to 20.0 psi
0 to 10.0 °F
1 to 100 psi
40 to 120 °F
0 to 100%
0 to 100%
None, Temperature, Lift
None, Valve SP, Valve
Stage, VFD Stage,
Valve SP/VFD Stage
NC, NO
1 to 4
1 to 60 min
1 to 60 min
10 to 130 psi
10 to 130 psi
10 to 130 psi
10 to 130 psi
1.0 to 20.0 psi
40 to 120 °F
40 to 120 °F
40 to 120 °F
40 to 120 °F
1.0 to 10.0 °F
PW
T Control gain for temperature (or lift) slope
T Control gain for temperature (or lift) error
T Maximum valve position, overrides all other settings
T Minimum valve position, overrides all other settings
T Condenser EWT at which initial valve position is set to max start position
T Initial valve position when condenser EWT is at or above Temp-Max Start Position
T Condenser EWT at which initial valve position is set to setpoint Stage Up @
Minimum position of valve when condenser EWT is at or below setpoint Stage
T
Down
T Sets control deadband, Cooling Tower Control =Lift
T Sets control deadband, Cooling Tower Control =Temp
Target for lift pressure (Cooling Tower Control = Lift), Works with Fan Stage Down
T
Time
Target for condenser EWT (Cooling Tower Control = Temp),
T
Works with Fan Stage Up Time
Valve position below which the fans can stage down
(Tower Valve/Fan VFD Strategy = Valve Stage)
T
VFD speed below which the fans can stage down
(Tower Valve/Fan VFD Strategy = VFD stage or valve SP/VFD stage)
Valve position above which the fans can stage up
(Tower Valve/Fan VFD Strategy = Valve Stage)
T
VFD speed above which the fans can stage up
(Tower Valve/Fan VFD Strategy = VFD or valve SP/VFD stage)
None: No tower control
T Temperature: Fan and valve controlled by condenser EWT
Lift: Controlled by lift pressure
None: No tower valve or VFD
Valve Setpoint: Valve controls to Valve Target and Valve Deadband
T Valve Stage: Valve controls between fan stages
VFD Stage: 1st fan is VFD controlled, no valve
Valve SP/VFD Stage: Both valve and VFD
T Normally closed or normally open to tower
T Number of fan stages used
T Time delay between stage up/down event and next stage up
T Time delay between stage up/down event and next stage down
T Lift pressure for fan stage #4 on
T Lift pressure for fan stage #3 on
T Lift pressure for fan stage #2 on
T Lift pressure for fan stage #1 on
T Fan staging deadband with Cooling Tower Control=Lift
T Temperature for fan stage #4 on
T Temperature for fan stage #3 on
T Temperature for fan stage #2 on
T Temperature for fan stage #1 on
T Fan staging deadband with Cooling Tower Control=Temp
49 IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Operation
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