Hitachi RAS-(4-6)HVRNS2E - Page 163

5 Control System
153
SMGB0064 rev.0 - 08/2011
5
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 specied opening.
a. Specied opening during heating operation: 1 minute
4 During the cooling and the defrosting operations, the electronic expansion valve is set at the specied 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.