Daikin RZQ71~125B7V3B, Service Manual, Page: 156 / 484

General Functionality ESIE04-01
2–18 Part 2 – Functional Description
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1.14 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:
Areas Defrost upper limit A
P
Integrated compressor running time is 25 minutes or more since
the completion of the previous defrost operation.
&
OR
P
Defrost upper limit time A is met.
P
Low pressure saturated temperature (Te) is within the
defrost requesting area.
P
Outdoor unit heat exchanger area temperature (Tb) is
within the defrost requesting area.
Defrost prohibiting area
Defrost permitting area
Evaporating temperature Te (°C)
or
Outdoor unit heat exchanger temperature Tb (°C)
When slightly quick defrost
starting is set
Factory setting
When slightly slow defrost
starting is set
When slightly quick defrost
starting is set
Defrost requesting area
When slightly quick defrost
starting is set
Factory setting
Outdoor
Temp. TA °C
When quick defrost
starting is set
16(26)-3-03
Factory setting
16(26)-3-01
When slow defrost
starting is set
16(26)-3-02
Outdoor temperature
> -5°C
40 minutes 3 hours 6 hours
Outdoor temperature
≤
-5°C
40 minutes 6 hours 8 hours
RZQ - Final.book Page 18 Wednesday, September 8, 2004 8:40 AM