CLIMAVENETA ACCURATE AXO Installation Manual page 27

EMPTYING AND CHARGING
The refrigerant circuits of the water-cooled chillers and air-condi-
tioners are already charged with refrigerant, either R407C, R22
or R134a (check the rating plate on the unit and the compressors
to see which type of refrigerant is used).
The air-cooled air-conditioners (AX*) and the ECR units that
require refrigerant connections to other units are pre-charged
Refrigerant (*)
R22 (Mineral oil)
R407C (POE)
Open any valves in the unit or in the system to ensure that all the components are involved in the emptying operation;
Connect a high efficiency vacuum pump to the Schrader fittings or to the 1/4" SAE fittings on the compressor suction and discharge side;
Connect a cylinder of refrigerant to the charge fittings.
Empty the lines, ensuring an absolute pressure of less than 100
Pa (0.7 mm Hg) for an extended period, so as to remove the air
and any traces of moisture.
The circuit should be emptied slowly and maintained for an extended period, rather than performed too quickly.
In general, if there is the chance of significant moisture content in the circuit or for very large systems, the vacuum must be "broken" with
nitrogen dioxide and then repeat the emptying operations as described.
Break the vacuum by pre-charging from the cylinder of R22
refrigerant.
After having started the compressor, complete the charge slowly, until the pressure stabilises in the lines and the gas bubbles disappear
from the flow indicator;
The charge must be checked at the environmental design conditions
and with a discharge pressure of around 18 bar (equal to a saturated
temperature of 48°C); for units with on-off condenser control, par-
tially close the intake to stop the condenser fan from repeatedly
starting-stopping.
Make sure that the subcooling of the liquid at the thermostatic valve
intake is between 3 and 5°C less than the condensing temperature
read on the pressure gauge and that the superheating of the vapour
at the evaporator outlet is around 5 °C.
The charge must be checked at the environmental design conditions
(*) recommended with COPELAND compressors.
If a circuit already charged with refrigerant needs to be emptied,
the first operation required is the removal of the refrigerant from
the circuit using a special appliance with dry compressor for
ACCURATE AX* - AW*
Mobil EAL Arctic 22 CC
R22
with nitrogen (or dry air) to prevent moisture from entering the
circuit; in this case, the refrigerant charge must be completed by
the installer, following the instructions shown in this paragraph.
Type of oil
Suniso 3 GS
Empty the lines, ensuring an absolute pressure of less than 10 Pa
(0.07 mm Hg) so as to remove the air and any traces of moistu-
re.
Break the vacuum by pre-charging from the cylinder of R407C
refrigerant in the liquid phase.
and with a discharge pressure of around 18 bar (equal to a dew
point of 48°C and boiling point of 43°C); for units with on-off con-
denser control, partially close the intake to stop the condenser fan
from repeatedly starting-stopping.
Make sure that the subcooling of the liquid at the thermostatic valve
intake is between 3 and 5°C less than the condensing temperature
read on the pressure gauge and that the superheating of the vapour
at the evaporator outlet is around 5 °C.
recovering the refrigerant.
If available, also switch on the sump heaters during the emptying
operation.
U I A
White oil
ICI EMKARATE RL 32S CF
R407C
English 01/07
25