Service manual

11-5
CONTROL SYSTEM
SM HADDCI 1-A.2 GB
11.1.7 EEV (electronic Expansion valve) Control
1. For S/W 37V3 and lower ( For 453031000R Controller)
EEV opening is defined as EEV = EEV
OL
+ EEV
CV
● EEV
OL
is the initial EEV opening as a function of the compressor frequency,
operation mode, unit model and capacity.
● EEV
CV
is a correction value for the EEV opening that is based on the compressor
temperature.
● During the first 5 minutes of compressor operation EEV
CV
= 0.
● Once the first 5 minutes are over, the correction value is calculated as follow:
EEV
CV
(n) = EEV
CV
(n-1) + EEV
CTT
● EEV
CTT
is the correction based on the compressor temperature. A target compressor
temperature is set depending on frequency and outdoor air temperature, and the
actual compressor temperature is compared to the target temperature to set the
required correction to the EEV opening.
2. For S/W 370V and higher (For 467300225R Controller)
The EEV will be operating according to the discharge super heat value.
Whenever the discharge super heat is too high,the EEV will be opening.
Whenever the discharge super heat is too low,the EEV will be closing.
In cooling, the discharge super heat is calculated by CTT-OMT
In heating, the discharge super heat is calculated by CTT-ICT
Normal values of discharge super heat
Cooling:18ºC-35ºC
Heating: 15ºC-32ºC
11.1.8 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.
11.2 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.
11.3 Cool Mode
NLOAD is calculated according to the difference between actual room temperature and user set
point temperature by PID 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.
11.4 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.
CONTENTS