Daikin WCT Series Operating & Maintenance Manual page 38

x) Error Gain, Set the control gain for error. Default is 25.
xi) Slope Gain, Set the control gain for slope. Default is 25.
NOTE: Setpoints Error Gain and Slope Gain are site specific dealing with system fluid mass,
component size and other factors affecting the reaction of the system to control inputs. These
setpoints should be set by personnel experienced with setting up this type of control.
c) If LIFT was selected for fan control, use
i) Valve Target, Set the VALVE TARGET (setpoint), usually 30 psi below the minimum fan stage
setpoint established in TOWER Stage #1 On (Lift). This keeps full flow through the tower until the
last fan is staged off.
ii) Valve Deadband (lift), Set VALVE DEADBAND, the default of 6 psi is a good place to start.
iii) Minimum Start Position, Set MINIMUM VALVE POSITION when EWT is at or below Temp-
Maximum Position. Default is 0%.
iv) Temp-Maximum Position, Set the EWT at which the valve position will be at (Minimum Start
Position). Default is 60F.
v) Valve Control Range (Min), Set the minimum position to which the valve can go. Default is 10%.
vi) Valve Control Range (Max), Set the maximum position to which the valve can go. Default is 100%.
vii) Error Gain, Set the control gain for error. Default is 25.
viii) Slope Gain, Set the control gain for slope. Default is 25.
NOTE: Setpoints Error Gain and Slope Gain are site specific dealing with system fluid mass, component
size and other factors affecting the reaction of the system to control inputs. These setpoints should be set
by personnel experienced with setting up this type of control.
Figure 23, Valve Positioning
Max Position
Min Position
See Errore. L'origine riferimento non è stata trovata.on page 16 for fan staging and
Tower Staging with Bypass Valve Controlled by Fan Stage (VALVE STAGE)
This mode is similar to #2 above except that the bypass valve setpoint changes to be set at the same
point of whatever fan stage is active rather than just maintaining a single minimum condenser EWT. In
this mode the valve controls between fan stages and tries to maintain the fan stage setting in effect.
When it is max open or max closed (staging up or down) and the temperature (or lift) moves to the next
fan stage, the valve will go the opposite max setting. This mode reduces fan cycling.
This mode is programmed the same as Mode #2 above except that in SETPOINT, TOWER, Tower
bypass Valve/Fan VFD, VALVE STAGE is selected instead of VALVE SP.
OMM WCT
Initial Valve Position
@ Setpoint
(90°F)
@ Setpoint
(60°F)
Min Start Position
Set Point (10%)
bypass valve field wiring connection points.
Centrifugal Chillers
Max Start Position
Set Point (90%)
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