Daikin UATYA-B, Operation Manual

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Service manual Daikin R32 Rooftops UATYA-B
ESIE21-02 – 2021.03
The speed of the fans will, in any case, be set within the range of the minimum and maximum values stored in parameters
“FA7” and “FA8” respectively in order to keep the stored flow rate setpoint.
Special conditions
If the device sensing the differential pressure on the fan nozzle experiences a malfunction, the controller will override the
output that controls ventilation at the average value measured in the last 30 minutes.
If the unit has been in operation for less than 30 minutes, the controller will stop the unit and it will output the corresponding
alarm.
3.9.3 Variable flow ventilation control
This function is used to change the air flow rate in the room as the temperature measured by the probe in the air return line
changes with respect to the temperature setpoint.
The parameters involved are shown in the table.
The values of the parameters are representative. In specific cases, different values can be set.
Parameter Value UM Description
ST1 27.0 °C Mechanical cooling - Temperature setpoint
STH1 20.0 °C Mechanical heating / Auxiliary heating in winter mode - Temperature setpoint
FA71 300 10 m
3
/h Variable air flow control - Cooling / Heating - Min. flow rate setpoint
FA72 825 10 m
3
/h Variable air flow control - Cooling / Heating - Max. flow rate setpoint
FA73 2.0 °C Variable air flow control - Cooling / Heating - Differenzial
FA74 0.0 °C Variable air flow control - Cooling / Heating - Neutral zone
FA75 0.0 °C Variable air flow control - Cooling / Heating - Offset
FA76 0 10 m
3
/h Variable / constant air flow control - Cooling / Heating - New air flow setpoint when the
temperature setpoint is reached
FA77 0 -
Variable / constant air flow control - Cooling / Heating - Enabling of new air flow
setpoint when the temperature setpoint is reached
FA81 0 10 m
3
/h Variable / constant air flow control - Defrost - New air flow setpoint
FA82 0 - Variable / constant air flow control - Defrost - Enabling of new air flow setpoint
PID47 25 - Air flow control for supply ventilation - Kp
PID48 15 - Air flow control for supply ventilation - Ki
PID49 0 - Air flow control for supply ventilation - Kd
PID53 50 10 m
3
/h Air flow control for supply ventilation - Dead band
PID55 1 - Air flow control for supply ventilation - Dead band position
PID64 0 - Air flow control for supply ventilation - Manual override (0 = Disabled)
The temperature setpoint used to calculate the flow rate setpoint is the cooling or heating temperature
setpoint, depending on which of the two operating modes is enabled.
The flow rate is measured indirectly by reading the difference in pressure measured on the fan nozzle. Units with multiple
fans only have the pressure difference measurement tap installed in one fan.
The controller calculates the air flow rate using the formula below.
Fig. 13 Formula for air flow rate calculation
3 Software functions