Automatic Cooling/Heating Operation Control; Preventive High-Pressure Increase Control - Hitachi RCI Service Manual

5 Control system

5.3.4 Automatic cooling/heating operation control

5

5.3.5 Preventive high-pressure increase control

This function is used to avoid an abnormal condition (alarm: 02) when the outdoor air flow drops due to seasonal winds
blowing against the air outlet. When CMC is enabled in cooling operation, PSC is enabled and Tc is greater than Tc1+4 °C,
operations with forced thermostat disabling are started.
Tc: Outdoor pipe temperature.
Tc1: Outdoor pipe temperature when the PSC is enabled.
PSC enabled: 3.60 MPa.
However, if this occurs more than 6 times during operations, thermostat stoppage is not forced. The cause of the stoppage
will be 13.
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SMGB0063 rev. 1 - 10/2010