Freeze-Up Protection Control; Outdoor Fan Control - Daikin FTKM-U Series Service Manual

SiMX042215E
3.6

Freeze-up Protection Control

Outline
During cooling operation, the signals sent from the indoor unit control the operating frequency
limitation and prevent freezing of the indoor heat exchanger. The signal from the indoor unit is
divided into zones.
Details
The operating frequency limitation is judged with the indoor heat exchanger temperature.
3.7

Outdoor Fan Control

1. Fan ON control to cool down the electrical box
2. Fan OFF delay when stopped
3. Fan speed control for pressure difference upkeep
4. Fan speed control during forced cooling operation
5. Fan speed control during POWERFUL operation
6. Fan speed control during indoor unit quiet operation
7. Fan ON/OFF control when operation (cooling, dry) starts/stops
Part 4 Functions and Control
13°C
Reset zone
A°C
Up zone
B°C
Keep zone
C°C
Dropping zone
0°C
Stop zone
A (°C) B (°C)
7 5
The outdoor fan is turned ON when the electrical box temperature is high while the
compressor is OFF.
The outdoor fan is turned OFF 70 seconds after the compressor stops.
The rotation speed of the outdoor fan is controlled for keeping the pressure difference during
cooling operation with low outdoor temperature.
 When the pressure difference is low, the rotation speed of the outdoor fan is reduced.
 When the pressure difference is high, the rotation speed of the outdoor fan is controlled
as well as normal operation.
The outdoor fan is controlled as well as normal operation during forced cooling operation.
The rotation speed of the outdoor fan is increased during POWERFUL operation.
The rotation speed of the outdoor fan is reduced by the command of the indoor unit quiet
operation.
The outdoor fan is turned ON when the operation starts. The outdoor fan is turned OFF
when the operation stops.
Indoor heat exchanger
thermistor temperature
C (°C)
3
Control Specification
(R22433)
41