Defrost Control - Daikin D Series Service Manual

SiBE12-519
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 30 minutes of accumulated fine 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
Operating room
450pps
electronic expansion
valve opening
Operation stopped room
140pps
electronic expansion
valve opening
0Hz
120sec.
530 sec.
5sec.
350pps
160pps
Control Specification
PI control
30sec.
5sec.
450pps
Initial opening
Initial opening
0pps
(R2962)
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