Refrigerant Loading - Trane CGCN Installation Operation & Maintenance

Refrigerant loading

WARNING! The units are designed to work with R410a refrigerant. DO NOT USE therefore different refrigerants
from R410a
WARNING! The addition or removal of refrigerant gas must be done in accordance with the laws and regulations
in force.
WARNING! When you add or remove the refrigerant from the system, ensure the proper flow of water through the
evaporator for the entire period of charge / discharge. The interruption of the flow of water during this procedure
would result in the freezing of the evaporator resulting in rupture of its internal pipes. Damage due to freezing will
void the warranty.
WARNING! The removal of refrigerant and charging the coil should be made by qualified technicians in the use of
material appropriate for the unit. Improper maintenance can lead to uncontrolled pressure loss and fluid. Also
does not disperse the refrigerant and the lubricating oil in the environment. Always wear a special system of
recovery.
Units are shipped with the total refrigerant charge, but there might be cases where it is necessary recharge the
vehicle on the ground.
WARNING! Always find the root cause of the refrigerant loss. If necessary, repair the system before proceeding
with recharging.
The charging of the unit can be made in any load condition stable (preferably between 70 and 100%) and in
every condition of temperature (preferably higher than 20°C). The unit should be maintained turned on for at
least 5 minutes to allow stabilization of the steps of the fans, and then the pressure of condensation.
About 15% of the condensing coils are dedicated for subcooling the liquid refrigerant. The value of subcooling is
equal to about 5-6°C (10-15 °C for units economized).
Once the section subcooling has been completely filled a further quantity of refrigerant is not increasing the
efficiency of the system. However a small amount of additional refrigerant (1 ÷ 2 kg) makes the system less
sensitive.
Note: By varying the load and the number of active fans, subcooling varied and requires some time to re-
stabilize. However it should never drop below 3 ° C in all conditions. Furthermore, the value of subcooling may
change slightly with changes in temperature of the water and the superheat of suction.
One of the following two scenarios may occur in a unit discharge of refrigerant:
1 If the unit is slightly discharge of refrigerant through the sight glass you can see the passage of bubbles. The
circuit as described in the charging process.
2. If the unit is moderately gas discharge, the corresponding circuit could have stops low pressure. Prime the
circuit as described in the corresponding charge.