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 pulseJ pulse
Initial opening
PI control
5 sec.
H sec.
(R18152)
Electronic expansion
valve opening
E sec.
F sec.
G sec.
L pulse
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