Control Specification
SiBE04-808_B
55
Function and Control
3.10 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.
Detail
Conditions for Starting Defrost
The starting conditions is 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 of accumulated time pass since the start of the operation, or ending the
previous defrosting.
Conditions for Canceling Defrost
The judgment is made with outdoor heat exchanger temperature. (4°C ~ 18°C)
20 class
25/35 class
42 class
50 class
A
(minutes)
28
28
30
44
B
(Hz)
76
76
48
55
C
(Hz)
86
86
70
90
D
(seconds)
50
50
60
60
E
(seconds)
60
60
120
120
F
(seconds)
600
600
650
460
G
(seconds)
50
60
30
30
H
(pulse)
450
450
450
450
J
(pulse)
350
350
350
450
K
(pulse)
450
450
450
450
Frequency
Compressor
Four way valve
Fan
ON
OFF
ON
OFF
ON
OFF
0Hz
B
Hz
C
Hz
5 sec.
J
pulse
K
pulse
H
pulse
Initial opening
PI control
5 sec.
G
sec.
(R13533)
Electronic expansion
valve opening
D
sec.
E
sec.
F
sec.
