SiUS091133
Control Specification
Function and Control
50
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 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.
Conditions for Canceling Defrost
The judgment is made with the outdoor heat exchanger temperature L.
09/12 class
15/18 class
24 class
30/36 class
A (minutes)
15 ~ 28
15 ~ 44
15 ~ 38
15 ~ 38
B (Hz)
76
55
39
39
C (Hz)
86
90
62
62
D (seconds)
50
60
60
60
E (seconds)
60
120
120
120
F (seconds)
480
340
530
530
G (seconds)
60
50
60
60
H (pulse)
450
450
450
450
J (pulse)
350
450
300
350
K (pulse)
450
450
400
400
L
4 ~ 18°C
(39.2 ~ 64.4°F)
4 ~ 12°C
(39.2 ~ 53.6°F)
4 ~ 12°C
(39.2 ~ 53.6°F)
4 ~ 18°C
(39.2 ~ 64.4°F)
Frequency
Compressor
Four way valve
Fan
ON
OFF
ON
OFF
ON
OFF
0 Hz
B Hz
C Hz
5 sec.
J pulse
K pulse
H pulse
Initial opening
PI control
5 sec.
G sec.
(R16577)
Electronic expansion
valve opening
D sec.
E sec.
F sec.
