Liquid Compression Protection Function; Defrost Control - Daikin Super Multi NX FFQ25B8V1B Service Manual

Control Specification
4.9

Liquid Compression Protection Function

Outline In order to obtain the dependability of the compressor, the compressor is stopped according to
the outdoor temperature and temperature of the outdoor heat exchanger.
Detail
Compressor turns off under the conditions that the system is in cooling operation and outdoor
temperature is below –12°C.

4.10 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 target heat exchanger temperature as the canceling condition is selected in the range of
4 ~ 12
120
Operation stops depending on the outdoor temperature
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 38 minutes of accumulated time pass since the start of the operation, or ending
the previous defrosting.
°C according to the outdoor temperature.
Frequency
60 sec.
ON
Compressor
OFF
ON
Four way valve
OFF
ON
Fan
OFF
450 pulse
Electronic expansion
valve opening
(operating room)
Electronic expansion
valve opening
(stop room)
50/52/58 class
A (Hz)
62
B (Hz)
80
B Hz
A Hz
0 Hz
120 sec. 530 sec.
5 sec.
350 pulse
160 pulse
68/75 class 80/90 class
54 39
82 62
SiBE121021_C
PI control
30 sec.
5 sec.
400 pulse
Initial opening
Initial opening
0 pulse
(R14552)
Function and Control