Hitachi RAS-(3-6)HVRNM2E Service Manual page 163

5 Control System
Outdoor unit electrical expansion valve control
1 After supplying power source, the electronic expansion valve is completely opened.
2 When the compressor is stopped, the electronic expansion valve is completely closed to adjust its opening.
3 At starting operation (compressor is operated), opening of the electronic expansion valve is set at a specified opening.
a. Specified opening during heating operation: 1 minute
4 During the cooling and the defrosting operations, the electronic expansion valve is set at the specified opening.
5 Normal opening of the electronic expansion valve.
• Coling operation
480 pulse (100%)
-
• Heating operation
a. Set of target temperature
TdSH = 20-25 ºC
b. Simulation PI control for the electronic expansion valve. The electronic expansion valve opening is controlled so
that the thermistor temperatures for the compressor can reach the target temperature.
153
SMGB0064 rev.0 - 08/2011
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