Freeze-Up Protection Control; Heating Peak-Cut Control - Daikin FTX-N Series Service Manual

SiUS091601EA
5.6

Freeze-up Protection Control

Outline During cooling operation, the signal sent from the indoor unit determines the frequency upper limit
and prevents freezing of the indoor heat exchanger. The signals from the indoor unit are divided
into zones.
Details
The operating frequency limitation is judged with the indoor heat exchanger temperature.
5.7

Heating Peak-cut Control

During heating operation, the indoor heat exchanger temperature determines the frequency upper
limit to prevent abnormal high pressure.
The operating frequency limitation is judged with the indoor heat exchanger temperature.
Stop zone
Dropping zone
Keep zone
Up zone
Reset zone
A
B 
C 
D 
E
: The valves might drop when the outdoor temperature is low to protect the compressor.
Part 4 Functions and Control
(Reference)
13°C (55.4°F)
Reset zone
7°C (44.6°F)
Up zone
5°C (41.0°F)
Keep zone
3°C (37.4°F)
Dropping zone
0°C (32.0°F)
Stop zone
B
C
D
Indoor heat exchanger
temperature
Zone
When the temperature reaches the stop zone, the compressor stops.
The upper limit of frequency decreases.
The upper limit of frequency is kept.
The upper limit of frequency increases.
The upper limit of frequency is canceled.
09/12 class
(°C) (°F) (°C)
59 138.2
55 131.0
52 125.6
50 122.0
45 113.0
Indoor heat exchanger
temperature (R2T)
Control
15 class 18/24 class
(°F) (°C)
60 140.0 60
54 129.2 56
51 123.8 53
49 120.2 51
44 111.2 46
Control Specification
Stop zone
A
Dropping zone
Keep zone
Up zone
E
Reset zone
(R23928)
(°F)
140.0
134.6
129.2
125.6
116.6
R4003644
84