Refrigerant Charge; Evacuation And Dehydration - Trane RTWD Installation Operation & Maintenance

Service and Maintenance

Refrigerant Charge

If a low refrigerant charge is suspected, fi rst determine
the cause of lost refrigerant. Once the problem is
repaired follow the procedures below for evacuating and
charging the unit.

Evacuation and Dehydration

1. Disconnect ALL power before/during evacuation.
2. Connect the vacuum pump to the 5/8" fl are
connection on the bottom of the evaporator and/or
condenser.
3. To remove all of the moisture from the system and to
insure a leak free unit, pull the system down below
500 microns.
4. After the unit is evacuated, perform a standing rise
test for at least an hour. The pressure should not rise
more than 150 microns. If the pressures rises more
than 150 microns, either a leak is present or moisture
is still in the system.
Note: If oil is in the system, this test is more diffi cult. The
oil is aromatic and will give off vapors that will raise the
pressure of the system.
Refrigerant Charging
Once the system is deemed leak and moisture free,
use the 5/8" fl are connections at the bottom of the
evaporator and condenser to add refrigerant charge.
Refer to General Data Tables and Unit nameplate for
refrigerant charge information.
Figure 24 - Recommended Oil Filter Replacement
GP2 / RTWD Clean FilterVersus Recommended Filter Replacement
GP2 / RTWD Clean Filter Versus Recommended Filter Replacement
Line
Line
92
CH530 RTWD Oil Pressure Protection Scheme
CH530 RTWD Oil Pressure Protection Scheme
Clean Filter below this line Clean Filter below this line
Refrigerant and Oil Charge Management
Proper oil and refrigerant charge is essential for proper
unit operation, unit performance, and environmental
protection. Only trained and licensed service personnel
should service the chiller.
Some symptoms of a refrigerant under-charged unit:
• Low subcooling
• Higher than normal discharge superheat
• Bubbles in EXV sight glass
• Low liquid level diagnostic
• Larger than normal evaporator approach temperatures
(leaving water temperature - saturated evaporator
temperature)
• Low evaporator refrigerant temperature limit
• Low refrigerant temperature cutout diagnostic
• Fully open expansion valve
• Possible whistling sound coming from liquid line (due
to high vapor velocity)
• High condenser + subcooler pressure drop
Start protection line for 1st
Start protection line for 1st
2.5 minutes of operation
2.5 minutes of operation
Run protection line after 2.5
Run protection line after 2.5
minutes of operation
minutes of operation
Recommended replacing fi lter
Recommend replacing filter
RLC-SVX14H-GB