Airwell YBZE218-324-430, Service Manual

Page: 43 / 68

CONTROL SYSTEM
Service Manual
– YBZE DCI 1-A.1 GB
12-7
12.5 Auto Cool/Heat Mode
In AUTO mode, the system selects the running mode (COOL/HEAT/FAN) automatically according
to the room temperature. The display shows the actual running mode and setting temperature.
There will be 30s delay for mode conversion.
1. When RAT
≥
26 degree, the cooling mode is selected.
2. When RAT
≤22 degree, the unit runs in heating mode
3. When 22 degree <RAT< 26 degree, upon initial startup, the unit will enter auto mode and run in
automatic fan mode. If the other mode changes into auto mode, the previous running mode will
remain. (Except from Dry Mode, system will run in automatic fan mode)
12.6 Dry Mode
Dry Mode is same as Cool Mode in EEV, OFAN and compressor control except following:
1) IFAN will be forced to Low speed.
2) For indoor working under Dry mode, Max capacity output is 90% of Cool Mode
In this mode, the Reverse Valve will be OFF and the temperature setting range is 16~30.
12.7 Protections
There are 4 protection codes.
Normal (Norm)
– unit operate normally.
Stop Rise (SR)
– compressor frequency can not be raised but does not have to be decreased.
HzDown
– Compressor frequency is reduced by 1Hz/s (2Hz/s for current protection)
Stop Compressor (SC)
– Compressor is stopped.
12.7.1 Mode confliction
When there are different mode settings among active indoors:
a. First request priority:
The first IDU which requests different mode than STBY mode will set the new operation mode.
Mode confliction
will be decided comparing with other IDUs’ modes. Cool (Dry) mode is conflict to
Heat mode.
The mode will change once all the units exit the current operation mode.
b. Fan mode is conflict to Heat mode:
Heat Mode is the priority mode, Fan Mode is conflict to Heat Mode no matter the IDU is first IDU or
not. The indoor will run in Heat Mode.
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