Hitachi RPI-4.0FSG1 - High Pressure Protection Device

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MAIN PARTS
3.8 High Pressure Protection Device
If the discharge pressure is excessively high, the compressor and the component parts of the
refrigeration cycle can be damaged. Therefore, in case that the discharge pressure is higher than
3.3/3.0MPa (R407C/R22), the protection control is activated and the compressor is stopped.
(1) For controlling the high pressure not to
increase excessively during heating
operation, the gas by-pass circuit and the
air volume of the outdoor fan is controlled
automatically.
(2) The gas by-pass circuit, which is composed
of the solenoid valve and the capillary tube
for flow adjustment, control the high
pressure not to increase excessively by
leading the high pressure gas to the low
pressure side.
Low Pressure
Sensor
High Pressure
Sensor
High Pressure
Switch
Union
MP
P
P
S
S
Solenoid
Valve
Gas By-pass Circuit
Capillary Tube
S
S
S