Control Specification
SiBE12-908
36
Function and Control
3.11
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 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. (40 class : 4°C~12°C, 50 class :
4°C~15°C)
Frequency
Compressor
Four way valve
Fan
Operating room
electronic expansion
valve opening
Operation stopped room
electronic expansion
valve opening
ON
OFF
ON
OFF
ON
OFF
0 Hz
5 sec.
450 pulse
350 pulse
450 pulse
Initial opening
0 pulse
40 class: 160 pulse
50 class: 200 pulse
140 pulse
Initial opening
PI control
5 sec.
30 sec.
60 sec.
530 sec.
120 sec.
120 sec.
40 class: 350 pulse
50 class: 300 pulse
(R7163)
