Daikin UATYA-B, Руководство по эксплуатации

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Service manual Daikin R32 Rooftops UATYA-B
ESIE21-02 – 2021.03
3.7 Priority between temperature and humidity control
The control of the air temperature in one room is closely connected to humidity control. In some installations both tempe -
rature and humidity need to be controlled, so there must be no excessive deviation from the setpoint of one of these two
variables.
This is why the controller features a function that prioritises either temperature or humidity or enables the system to give
priority automatically.
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
ST11 0 - Type of temperature control
ST15 0 - Cooling / Dehumidification operating mode
ST17 5 % Offset for changeover to new operating mode (only with ST15 = 0)
HU12 1 - Humidity control type
The value set in parameter “ST15” determines whether the priority is given:
- 0 = automatically;
- 1 = to cooling;
- 2 = to de-humidification.
Temperature and humidity may also be managed with a different control type. For instance: temperature may be controlled
proportionally and humidity with a PID control, or vice versa.
In both cases, the controller converts the demand into a 0 to 100.0% value and prioritises thermoregulation, based on the
two demands and the set values.
Automatic priority
When the controller is started up, priority is given to the demand for either cooling or dehumidification based on which of
the two is higher.
Once attributed, priority is kept until the other demand is either higher or equal to the demand plus the percentage value
set in parameter “ST17”.
Example using parameter “ST17” set to 5%
- Upon start-up, the cooling demand is 50% and the de-humidification demand is 48%. Priority is given to cooling: com -
pressor thermoregulation is at 50%.
- If, during operation, the temperature drops and humidity stays unaltered, the cooling demand drops to 47% after a while
and the de-humidification demand increases to 50%. Priority is still given to cooling because the difference between the
two demands does not exceed the percentage value set in parameter “ST17”. The controller enables resources, based
on the cooling demand at 47%.
- If the temperature drops to 45% and humidity stays unaltered after a while, the difference between the two demands
now equals the percentage value set in parameter “ST17”. The controller shifts the priority from cooling to de-humidifi -
cation. The controller enables resources, based on the de-humidification demand at 50%.
Priority to cooling
When priority is given to cooling, the cooling demand is always prioritised, irrespective of the value.
In other words, if the cooling demand is 50%, for instance, and the de-humidification demand is 100%, the controller
enables resources at 50%.
Priority to de-humidification
When priority is given to de-humidification, the de-humidification demand is always prioritised, irrespective of the value.
In other words, if the de-humidification demand is 50%, for instance, and the cooling demand is 100%, the controller
enables resources at 50%.
3 Software functions