Hitachi RAS-3HVRNS - High Pressure Protection Device

11.4 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 4.15 MPa (R410A), the protection control is activated
and the compressor is stopped.
1. Electrical box.
2. Upper cover.
3. Rear cover.
4. Brazing.
5. Pressure switch for control (PSC).
6. Discharge pipe.
7. High pressure switch (PSH).
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.
1. Gas by-pass circuit.
2. Capillary tube.
3. Solenoid valve.
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11 Electrical checks of
main parts
448
SMGB0060 rev. 1- 12/2010