Midea V8 VRF Series Service Manual page 32

4.4 Fan Control
4.4.1 Fan speeds control
The IDU can work in seven-speeds

Seven-speeds
When the Indoor Unit detects only seven wind speeds the wind speed is set as follows.
Sleep Speed 1 Speed 2
For the specific model type, please consult the technical manual of each model. The following table describes the fan
control in different situations

Fan control in different situations
IDU Status
Operating Operating
in Set Standby
Speed
Off
Fault
IDU Status
Operating
Automatic
Standby
Fan Speed
Off
Fault
Note:
Termal: In the heating mode, The IDU in the standby state heating mode will run fan periodically at speed 1 for one minute (the period can be set)
4.4.2 Auto fan control mode
1. When set auto fan control in cooling or heating mode. After operation in the initial speed for a period of time, when
Thermal ON, IDUs enter the auto mode and the fan speed will be changed every 2 minutes or when Ts change.
2. When Thermal OFF, IDUs enter the standby mode. When Thermal ON, IDUs enters the initial fan speed again.
3. The default speed is speed 1 when IDUs are set auto fan mode in Air supply only mode.

Determine the initial fan speed of auto fan control
The initial fan speed is determined according to the difference
between ambient indoor temperature (T1) and set temperature (TS),
and it updates in the following situations:
1) The first time enter this mode
2) TS is changed
3) When switching between normal operation and silent operation
Speed 3 Speed 4
Cooling Mode Dry Mode
Set speed Speed 1
Set speed Speed 1
Stop fan Stop fan
Stop fan Stop fan
Cooling Mode Heating Mode
Automatic Automatic
Automatic Termal
Stop fan Stop fan
Stop fan Stop fan
Speed 5 Speed 6
Heating Mode
Set speed
Termal
Stop fan
Stop fan
Auto
Automatic
Automatic cooling, automatic fan speed,
automatic heating, and Termal mode
operating
Stop fan
Stop fan
V8 VRF Indoor Units
Speed 7 Auto
Fan Mode
Set speed
/
Stop fan
Stop fan
Fan Mode Speed Switch
Low
Switch fan speed
/ difference of the set
temperature and
Stop fan
Stop fan
Speed Switch
User set
based on the
return air
temperature
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