Refrigerant Charging - Trane RTWB Helical-Rotary Installation Operation & Maintenance

Refrigerant charging

If the refrigerant needs to be
adjusted, be certain to monitor the
subcooling and superheat
measurements. The subcooling
needs to be between 6 and 12°C
when the unit is running fully
loaded. The superheat needs to be
close to, or at, the superheat
setpoint entered in the UCM.
C C A A U U T T I I O O N N
The evaporator water flow must be
established and maintained while
adjusting the charge. Refrigerant
pressures below 2,3 bar gauge can
cause freezing and rupturing of the
evaporator tubes.
RTWB-SVN01B-E4
Periodic
Maintenance
Adding refrigerant
The RTWB units are shipped with an
entire charge of refrigerant and oil. If
the unit has no pressure, the system
must be leak tested prior to adding
refrigerant. Evacuate the system
down to at least 500 microns prior to
adding the refrigerant.
C C A A U U T T I I O O N N
Water must be flowing through the
tube bundles during this entire
process. Refrigerant pressures
below 2,3 bar gauge can cause
freezing and rupturing of the heat
exchangers.
1. Connect 110 V power to the
female stepload solenoid and the
male load/unload solenoids. This
must be done to evacuate all of
the cavities in the compressor.
2. Open all service valves.
3. Connect hoses from the vacuum
pump to the LP and HP ports on
the unit.
4. Evacuate the system to 500
microns and isolate the vacuum
pump.
5. Confirm that no moisture or
leaks are present by letting the
vacuum stand for 2 hours. The
pressure should not raise more
than 250 microns.
6. Close the liquid line valve placed
at the outlet of the condenser.
7. Open the EXV and add
refrigerant by using the charging
valve placed on the liquid line.
8. After the pressure between the
refrigerant bottle and the
refrigerant circuit is balanced,
make a vacuum by using the
compressor in order to store the
refrigerant in the condenser.
9. Continue to charge the machine
by using the refrigerant charging
valve placed on the liquid line.
10. After the pressure is balanced
between the bottle and the
machine, open the liquid line
valve and start the compressor.
11. Complete the charge by using
the charging valve placed on the
suction line. For the correct
refrigerant charge refer to the
Table 2.
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