Service Manual

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 pulseH pulse
Initial opening
PI control
5 sec.
G sec.
(R16577)
Electronic expansion
valve opening
D sec.
E sec.
F sec.