Defrost Control - Daikin RZQG71L9V1 Service Manual

ESIE15-13C
Dew condensation prevention control
Dry operation with horizontal airflow is carried out for 1 hour. (P2)
1. When there is any change to heating/fan modes, airflow direction and operation ON/OFF
Note:
3.1.8 Freeze-up Prevention Control
The unit will perform the forced thermostat off function in following conditions:
3.1.9 Monitoring Control
When the indoor unit fan is turned off while the thermo. for cooling, heating and drying is off,
even if the indoor unit temperature recovers afterwards and becomes the one that turns the
thermo. on, the thermistor cannot detect indoor unit temperature because the suction air
thermistor of indoor unit is installed inside the machine.
In order to prevent such a condition, this monitoring control has the function of detecting indoor
unit temperature by operating the fan at certain intervals when the fan is turned off while the
thermo. is off.

3.1.10 Defrost Control

When the heating operation continues at a low outdoor air temperature, the frost adhered to the
surface of outdoor heat exchanger deteriorates heating capacity.
When the amount of adhered frost exceeds a certain level, the operation will automatically
switch to the cooling cycle to melt the frost.
When the frost is melted, the normal heating operation will be resumed.
3.1.11 Draft Avoidance Control
In order to prevent cold wind from directly blowing to the user when the indoor heat exchanger
temperature is low, such as the timing that heating started and defrost ended, this control has
the function of changing the airflow rate to LL tap and fixing the airflow direction to horizontal.
Function and Control
state during dew condensation prevention control, this control is reset.
Thermostat off due to freeze-up prevention.
Based on the judgement to prevent the indoor heat exchanger from freezing, the thermostat
is forcedly turned OFF.
Indoor unit
heat exchanger
temperature
-1ºC
-3ºC
-5ºC
*1 FHQG Only
Freeze-up prevention control
Reset after a continuous 10 minutes and cumulative
timer cleared after a continuous 10 minutes
7ºC
Cumulative timer cleared after a continuous 20 minutes
4ºC
The thermostat turns OFF after a cumulative 40
minutes
The thermostat turns OFF after a continuous 1 minute
after 8 minutes from startup (1)
The thermostat turns OFF after a continuous 1 minute
after 8 minutes from startup
Function Details
35