Free Cooling - Daikin RZQG71L9V1 Service Manual

Function Details
Example cooling:
A= 13°C Te lower limit
B= 6°C Te lower limit
C= 17°C Ta
D= 27°C Ta
Example heating:
A= 49°C Tc upper limit
B= 44°C Tc upper limit
C= 2°C Ta
D= 18°C Ta
3.2.33 Slow start for EDP applications
There is new setting available that will allow the unit to perform a slow start to avoid that the unit
would already receive a thermo-off when it is still running in start-up mode. This setting is
required when the cooling capacity is oversized.
The merit of this settings is that by lowering the frequency of the compressor (and hereby the
capacity) the unit will get a chance to modulate and avoid early thermo off.
•
•
When you make setting 26-7-02 then you will at the same time activate a bigger thermo on/off
hysteresis.
•
When setting 26-7-2 is set the slow start will be activated when DT-rs ≤ 4,5°C.
If DT-rs becomes bigger then 5°C the unit will perform a normal start.

3.2.34 Free cooling

If ambient conditions are low, it would be beneficial to use the fresh air supply to cool the rooms
instead of using the actual system.
However at the installation the intake volume + humidity needs to be controlled by external
system. The outdoor unit can only give the signal that based on temperatures and demand
when free cooling can be used.
Avoid that the fresh outdoor air can short circuit to the indoor unit.
The free cooling 230 V signal will be supplied through the optional PCB KRP58M51and outdoor
unit setting 2-53-xx.
54
Te Lower Limit
Tc Upper Limit
A
B
C
The setting that is required is 26-7-02.
This setting must always be combined with the EDP setting 26-2-03.
Normal hysteresis is DT-rs= ((TaIU - Tset) - 0,5) = 2°C.
D Ta
ESIE15-13C
Function and Control