
8 Electrical checks of the main parts
Pressure protection devices
SMGB0091 rev.2 - 11/2015
138
8.4
Pressure protection devices
8.4.1
Location of the pressure protection devices
RASC-(4-6)HNPE
RASC-(8/10)HNPE
High pressure
switch (PSH)
Low pressure
switch (PSL)
Discharge pressure
sensor for control (Pd)
High pressure
switch (PSH)
Low pressure
switch (PSL)
Discharge pressure
sensor for control (Pd)
8.4.2
Description of the pressure protection devices
High pressure switch (PSH)
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.
Discharge pressure sensor for control (Pd)
This pressure sensor allows the performance control of several components: fan motor performance, protection against
high pressure, compressor frequency control, opening of the valves, etc.
Low pressure switch (PSL)
For internal control.