Daikin RZQ Series FCQ20EVA Service Manual page 54

Function Details
4.2.23 Defrost Operation
Outline
When the unit is operating in heating mode, a defrost operation will be conducted in order to avoid ice
formation on the outdoor unit heat exchanger.
Defrost Starting Conditions
Defrost will start when the following conditions have been realized:
• Integrated compressor running time is 25 minutes or more since the completion of the previous defrost
operation.
&
• Defrost upper limit time A is met.
• OR
• Outdoor unit heat exchanger temperature is within the defrost requesting area.
Areas
Defrost upper limit time A
Outdoor air temperature > -5°C
Outdoor air temperature  -5°C
-20 -15 -10
-4
-6
-7
-8
-9
-10
-11
-12
-14
Defrost permit
area
-17
-21
-23
-24
-27
-28
45
When quick defrost
starting is set 16(26)-3-03
40 minutes
40 minutes
Outdoor unit heat exchanger temperature (˚C)
5
2
0
-5
10
5
-1
-1
-7
-2
-4
-3
-5
-5
-6
-8
-8
-10
-11
-7
-13
-15
-16
Defrost request
area
-20
-19
-25
-30
Factory setting
16(26)-3-01
2 hours
6 hours
When slightly quick defrost starting is set (Permit)
15
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)
SiME281501E
When slow defrost
starting is set 16(26)-3-02
6 hours
8 hours
Outdoor air temperature (˚C)
Function and Control