Daikin FBQ50D - Defrost Operation

Function Details ESIE15-13C
48 Function and Control
3.2.25 Defrost Operation
When in heating mode, a defrost operation will be conducted in order to avoid ice formation on
the outdoor unit heat exchanger.
Starting Conditions
Defrost will start when the following conditions have been realized:
Defrost conditions
Defrost upper limit A
Depending on the defrost start setting (field setting mode of the indoor unit remote controller),
frost upper limit time A becomes as shown in the table below.
&
• Integrated compressor running time is 25 minutes or more since the completion of the
previous defrost operation.
OR • Defrost upper limit time A is met.
• Outdoor unit heat exchanger temperature is within the defrost request area.
When quick
defrost starting is
set
Factory setting
When slow defrost
starting is set
Outdoor air temperature > -5°C 40 minutes 2 hours 6 hours
Outdoor air temperature ≤ -5°C 40 minutes 6 hours 8 hours
-20 -15 -10
5
0
-3
-5
-6
-10
-7
-15
-20
-23
-17
-10
-7
-4
-7
-5
-5
-8
-13
-16
-19
-21
-12
-9
-6
-24
-27
-28
-14
-11
-8
-8
-2
-25
-30
15
5
2
-1
-4
-1
-11
10
Outdoor unit heat exchanger temperature (°C)
Defrost permit
area
Defrost request
When slightly quick defrost starting is set (Permit)
Outdoor temperature (°C)
Factory setting (Permit)
When slightly quick defrost starting is set (Request)
When slightly slow defrost starting is set (Permit)
Factory setting (Request)
When slightly slow defrost starting is set (Request)