Freeze Protection Function In Cooling - Daikin FTK25JVE9 Service Manual

Si04-115
1.14

Freeze Protection Function in Cooling

Outline During Cooling/Dry operation, when the heat exchanger's temperature falls down excessively,
the capacity supply will be reduced (frequency step down) so as to prevent freeze of the heat
exchanger and the creation of dew on a rotor caused by a excessive capacity supply to the
indoor unit.
Processing
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Main Function
DTO4
Return
DTO3
Up-area
DTO2
Steady area
DTO1
Step down area
DTO0
Stop area
at the descend of
heat exchanger temp.
Setting a constant
DTO4
DTO3
DTO2
DTO1
DTO0
DTO : Freeze protection temperature of heat exchanger
The restriction for frequency is not conducted in the return area by means of freeze
protection control.
Frequency is increased approximately every 2 Hz/min. in the up-area.
Frequency alteration in the steady area is not conducted.
Frequency - down is carried out in the step down area approximately every 2 ~ 4 Hz/min..
Compressors stop in the stop area. After compressor stops, fan keeps operating in 800 rpm
(LL tap), aiming at rising heat exchanger's temperature.
at the rise of heat exchanger temp.
J type
15°C
8°C
7°C
5°C
0°C
General Functionality
Return from stop.
(R1920)
35