Service manual

13-4
CONTROL SYSTEM > GC 18/GC 21
SM HADDCI 1-A.2 GB
13.1.11 Reversing Valve (RV) Control
Reversing valve is on in heat mode.
Switching of RV state is done only after compressor is off for over 3 minutes.
13.1.12 ionizer Control
Ionizer is on when unit is on AND indoor fan is on AND Ionizer power switch (on Ionizer) is on.
13.2 Fan Mode
In high/ medium/ low indoor fan user setting, unit will operate fan in selected speed.
In AutoFan user setting, fan speed will be adjusted automatically according to the difference between
actual room temperature and user set point temperature.
13.3 Cool Mode
NLOAD is calculated according to the difference between actual room temperature and user set
point temperature by PI control.
In high/ medium/ low indoor fan user setting, unit will operate fan in selected speed.
In AutoFan user setting, fan speed will be adjusted automatically according to the calculated
NLOAD.
13.4 Heat Mode
NLOAD is calculated according to the difference between actual room temperature and user set
point temperature by PI control.
In high/ medium/ low indoor fan user setting, unit will operate fan in selected speed.
In AutoFan user setting, fan speed will be adjusted automatically according to the calculated
NLOAD.
13.4.1 Temperature Compensation
In wall mounted, ducted, and cassette models, 3 degrees are reduced from room temperature reading (except
when in I-Feel mode), to compensate for temperature difference between high and low areas in the heated
room, and for coil heat radiation on room thermistor.
The temperature compensation can be enabled/disabled by shortening of J2 on the indoor unit Controller.
Model J2 Shorted J2 Opened
Wall mounted Compensation Disabled Compensation Enabled
Cassette Compensation Enabled Compensation Disabled
Ducted Compensation Enabled Compensation Disabled
Floor/Ceiling Compensation Disabled Compensation Enabled
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