Defrost Control - Daikin F-Series Service Manual

SiBE04-705
3.10

Defrost Control

Outline Heat Pump Only
Defrosting is carried out by the cooling cycle (reverse cycle). The defrosting time or outdoor
heat exchanger temperature must be more than its fixed value when finishing.
Detail Conditions for Starting Defrost
The starting conditions must be made with the outdoor air temperature and heat exchanger
temperature. Under the conditions that the system is in heating operation, 6 minutes after the
compressor is started and more than 44 minutes of accumulated time pass since the start of the
operation or ending the defrosting.
Conditions for Canceling Defrost
The judgment must be made with heat exchanger temperature. (4°C~12°C)
Function and Control
Frequency
60sec.
ON
Compressor
OFF
ON
Four way valve
OFF
ON
Fan
OFF
Electronic expansion
450pulse
valve opening
2YC36 : 90Hz
2YC63 : 74Hz
55Hz
0Hz
120sec.
460 sec.
5sec.
450pulse
Control Specification
PI control
30sec. (50 class)
50sec. (60/71 class)
5sec.
450pulse
Initial opening
(R6978)
51