Defrost Control - Daikin J Series Service Manual

SiBE041101

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
Conditions for Canceling Defrost
The judgment is made with outdoor heat exchanger temperature. (J°C)
A (minutes)
B (Hz)
C (Hz)
D (seconds)
E (seconds)
F (seconds)
G (seconds)
H (pulse)
J (°C)
Function and Control
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 A minutes of accumulated time pass since the start of the operation, or ending the
previous defrosting.
Frequency
ON
Compressor
OFF
ON
Four way valve
OFF
ON
Fan
OFF
Electronic expansion
valve opening
20 class
28
76
86
50
60
600
50
350
4 ~18
B Hz
0 Hz
E sec.
D sec. F sec.
5 sec.
450 pulse
H pulse
25/35 class 42 class
28 30
76 48
86 70
50 60
60 120
600 650
60 30
350 350
4 ~18 4 ~15
Control Specification
C Hz
G sec.
5 sec.
450 pulse
Initial opening
50 class
44
55
90
60
120
460
30
450
4 ~12
PI control
(R13533)
44