50
Ensure that the oil sump heaters have been operating for a minimum of 12 hours before starting and
power of evaporator heater and pump always on. Failure to do so may result in equipment damage.
Refrigerant Field Charge to an undercharged unit
This procedure should be followed when adding refrigerant to an undercharged unit.
1. Once the system is deemed shortage, refer to
, loosely attach charge hose to the service valve of
suction side of the unit with the R134a tank.
2. Open the valve of refrigerant tank to evacuate the air in the charging hose.
3. Add no more than 4.5kg gas refrigerant into the circuit during compressor operation.
4. After the unit has operated for approximately 30 minutes and the system has stabilized, check the subcooling
and approach temperature. Repeat from Step 3 till subcooling or approach temperature back to normal.
5. Close the service valve and remove the hose.
NOTICE - Insufficient Subcooling!
Proper subcooling can be determined by operator log, service technician experience or consulting
Trane local service.
NOTICE - Gas Refrigerant Adding!
Add gas refrigerant only during operation to avoid compressor failure.
Refrigerant Recycling
Refrigerant used in any type of air-conditioning or refrigerating equipment should be recovered and/or
recycled for reuse, reprocessed (reclaimed). Recovering the refrigerant charge from the system should be
done using certified recycling equipment and approved storage containers and by following proper
procedure. Never release refrigerant into the atmosphere or discharge refrigerant into the container by
compressor operation of the unit.
Recover the refrigerant through the service port of liquid line and evaporator. The following information is to
be noted for refrigerant recovery.
•
Only trained and qualified service personnel should recover refrigerant with Personal Protective Equipment
(PPE).
•
The workplace shall be well ventilated, away from inflammable and explosive materials, rain and moisture.
•
Disconnect all electric power of the unit and lockout before refrigerant recovery.
•
Use only approved storage container for recycled refrigerant. To prevent on-site over filling, the safe filling
level must be controlled by weight and must not exceed 60% of container gross weight rating. Comply with
all applicable transportation standards when shipping refrigerant container.
Refrigerant Filter Replacement Procedure
A dirty filter is indicated by a temperature gradient across the filter, corresponding to a pressure drop. If the
temperature downstream of the filter is 2.22
o
c lower than the upstream temperature, the filter should be
replaced. A temperature drop can also indicate that the unit is undercharged. Ensure proper subcooling
before taking temperature readings.
1. Normal Stop the unit, manually close all EXVs by TD7.
Disconnect all electric power of unit and lockout.
