Daikin UATYA-B, Руководство по эксплуатации

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Service manual Daikin R32 Rooftops UATYA-B
ESIE21-02 – 2021.03
Cascade control
The Cascade function refers to the setpoint value entered in parameter “ST42”. This value is also used as reference for
automatic mode switching when parameter “SP40” is set to “4”, together with parameters “ST43” and “STH46”.
The reference temperature is the air temperature in the delivery line. Mode switching takes place as follows:
- if the air temperature in the return line is higher than the sum of the setpoints in parameters “ST42” and “ST43”, the
controller sets unit operation in cooling mode;
- if the air temperature in the return line is lower than the difference between the setpoints in parameters “ST42” and
“STH46”, the controller sets unit operation in heating mode;
- if the air temperature in the return line is included between the sum of parameters “ST42” and “ST43” and the difference
of parameters “ST42” and “STH46”, the controller keeps the unit running in the last set mode.
3.18.6 Flow rate reduction upon achievement of temperature setpoint
In applications specifically designed for this purpose, the controller features the possibility to reduce the air flow rate when
the temperature setpoint is achieved.
The parameters involved are shown in the table.
This function is disabled and the second flow setpoint is blank when the unit is released from the factory.
Parameter Value UM Description
FA76 0 10m3/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
RFA29 0 10m3/h PID - Constant air flow control - New air flow setpoint when the temperature setpoint
is reached
RFA30 0 -
PID - Constant air flow control - Enabling of new air flow setpoint when the temperatu -
re setpoint is reached
“FA” parameters refer to the flow rate in the delivery line; “RFA” parameters refer to the flow rate in the return line.
If the value set in parameters “FA76” and “RFA29” is = “0”, the ventilation system is switched off as soon as
the temperature setpoint is achieved.
3 Software functions