Defrost Control - Daikin FFQ09Q2VJUFFQ12Q2VJUFFQ15Q2VJUFFQ18Q2VJURX09QMVJURX12QMVJURX15QMVJURX18QMVJU Service Manual

Control Specification

2.10 Defrost Control

Outline Defrosting is carried out by the cooling cycle (reverse cycle). The defrosting time or outdoor heat
exchanger temperature must be more than a certain value to finish defrosting.
Details Conditions for Starting Defrost
Conditions for Canceling Defrost
The judgment is made with the outdoor heat exchanger temperature (B).
A (minute)
B
C (Hz)
D (Hz)
E (seconds)
F (seconds)
G (seconds)
H (seconds)
J (seconds)
K (pulse)
L (pulse)
M (pulse)
39
The starting conditions are determined with the outdoor temperature and the outdoor heat
exchanger temperature.
The system is in heating operation.
The compressor operates for 6 minutes.
More than A minutes (depending on the duration of the previous defrost control) of accumulated
time have passed since the start of the operation, or ending the previous defrosting.
Frequency
ON
Compressor
OFF
ON
Four way valve
OFF
ON
Fan
OFF
Electronic
expansion valve
opening Normal
control
09/12 class
20 ~ 25
(°C) 2 ~ 20
(°F) 35.6 ~ 68.0
64
64
40
60
510
50
8
400
300
350
D Hz
C Hz
0 Hz
F sec.
E sec. G sec.
J sec.
K pulse L pulse zone
zone
15/18 class
25
6 ~ 30
42.8 ~ 86.0
48
42
60
60
340
60
5
450
300 ~ 450
300
SiUS091628EA
PI control
0 Hz
H sec.
8 sec.
Starting
M pulse
zone control
(R21661)
Functions and Control