PKG-SVX19B-E4
28
Evacuation of the refrigeration circuit and charging of refrigerant
WARNING! The charging and maintenance of the refrigeration circuit must only be carried out by a
qualified hydraulic technician.
The refrigeration circuit is pre-charged with nitrogen.
To load the refrigerant, carry out the following procedure:
R410A
• open any shut-off valves present in the machine to
ensure that all of the components will be evacuated;
• connect a pump to empty the schrader connections
efficiently, or to the 1/4» SAE connections present on
the intake and delivery sides of the compressors;
• connect the refrigerant cylinder to the loading
connections;
• create a vacuum within the lines whilst maintaining the
pressure below 10 Pa absolute (0,07 mm Hg) for a long
time in order to evacuate the air as well as any trace
of humidity. It is preferable that the vacuum is reached
slowly and maintained for a long period of time;
• wait for a build up period of 100 seconds and check
that the pressure has not exceeded 200 Pa absolute.
Generally, in the case of suspicion of strong hydration
of the circuit or an extremely extensive system, it will
be necessary to break the vacuum with anhydrous
nitrogen and then repeat the evacuation procedure as
described;
• break the vacuum by performing a preload in liquid
phase from the R410A coolant cylinder;
• after having started the compressor, slowly complete
the loading phase until the pressure within the lines
has been stabilised and the gaseous bubbles have
disappeared from the flow sight glass;
• the loading process must be controlled in environmental
conditions with a delivery pressure of approximately
18 bar (equivalent to a dew temperature of 48 °C and
a bubble temperature of 43 °C); in the case of units
with ON/OFF condensation controls, avoid switching
the condenser fan on and off, which may partially
obstruct the intake surface. It is wise to check that the
sub-cooling of the liquid at the entry of the thermostatic
valve is between 3 and 5 °C below the condensation
temperature read on the scale of the pressure gauge
and that the overheating of the vapour at the exit of the
evaporator is equal to approximately 5-8 °C.
Type of oil recommended with MANEUROP compressors
Type of oil recommended with SANYO compressors
Type of oil recommended with Scrolltech HRH-HLH-HLJ-HCJ compressors
R410A (PVE)
PVE FVC68D
R410A (POE)
Maneurop 160 SZ
R410A (PVE)
FV68S
