Control Specification
SiBE041010EA
37
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 defrosting.
Detail
Conditions for Starting Defrost
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 of accumulated time pass after the start of the operation, or ending the
previous defrosting.
Conditions for Canceling Defrost
The judgment is made with the outdoor heat exchanger temperature. (
B
°C)
20/25 class
35 class
A
(minutes)
28
28
B
(°C)
4 ~ 22
4 ~ 22
C
(Hz)
68
72
D
(Hz)
80
84
E
(seconds)
80
80
F
(seconds)
60
60
G
(seconds)
510
510
H
(seconds)
100
70
J
(pulse)
450
450
K
(pulse)
400
400
L
(pulse)
430
430
M
(pulse)
450
450
Frequency
Compressor
Four way valve
Fan
ON
OFF
ON
OFF
ON
OFF
0 Hz
0 Hz
C
Hz
D
Hz
5 sec.
K
pulse
M
pulse
J
pulse
Initial opening
PI control
5 sec.
H
sec.
(R18152)
Electronic expansion
valve opening
E
sec.
F
sec.
G
sec.
L
pulse
