Defrost Control; Defrost Starting Condition; Defrost Condition - Daikin SkyAir Super Inverter 70 D Series Service Manual

SiE25-110

4.2.24 Defrost control

When heating operation, defrost operation is conducted to melt frost on outdoor unit heat
exchanger.

[Defrost starting condition]

Defrost condition

Defrost upper limit time A
When Outdoor temperature>–5 ˚C, A = 3 hours
When Outdoor temperature≤–5 ˚C, A = 6 hours
Heating integral capacity
Function and Operation
Intelligent type
Defrosting starts when the following conditions have been realized.
Integral compressor run time is 25 minutes or more from the completion of previous defrost operation.
Low pressure equivalent saturation temperature (Te) is within the defrost permitting area.
Outdoor unit heat exchanger temperature (Tb) is within the defrost permitting area.
&
Defrost upper limit time A is met.
Low pressure equivalent saturation temperature (Te) is within the defrost requesting area.
OR
Outdoor unit heat exchanger temperature (Tb) is within the defrost requesting area.
Heating integral capacity is low.
Evaporating temperature Te (˚C)
or
Outdoor unit heat exchanger temperature Tb (˚C)
Defrost prohibiting area
Defrost permitting area
Compressor running time
Heating
When slightly quick defrost starting is set
Outdoor
temperature Ta(˚C)
Factory setting
When slightly slow defrost starting is set
When slightly quick defrost starting is set
Factory setting
When slightly slow defrost starting is set
Defrost requesting area
Maximum integral capacity value
Diminishing integral capacity
Defrosting
Function Details
(S2554)
(S2555)
(S2556)
93