Control Specification
SiBE12-933_A
88
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 30 minutes of accumulated time pass since the start of the operation, or ending
the previous defrosting.
Conditions for Canceling Defrost
The target heat exchanger temperature as the canceling condition is selected in the range of
E
°C according to the outdoor temperature.
Frequency
Compressor
Four way valve
Fan
ON
OFF
ON
OFF
ON
OFF
0 Hz
A
Hz
C
pulse
5 sec.
450 pulse
350 pulse
450 pulse
Initial opening
0 pulse
D
pulse
140 pulse
Initial opening
PI control
5 sec.
30 sec.
60 sec.
530 sec.
120 sec.
(R12739)
B
Hz
40 class
70
86
350
160
4 ~ 12
50 class
48
70
300
200
4 ~ 15
A
(Hz)
B
(Hz)
C
(pulse)
D
(pulse)
E
(˚C)
Electronic expansion
valve opening
(operating room)
Electronic expansion
valve opening
(stop room)