Installation and Maintenance Manual

Service and Maintenance
RLC-SVX09H-EN 191
Refrigerant Charge
If a low refrigerant charge is suspected, first determine the
cause of lost refrigerant. Once the problem is repaired
follow the procedures below for evacuating and charging
the unit.
Evacuation and Dehydration
5. Disconnect ALL power before/during evacuation.
6. Connect the vacuum pump to the 5/8” flare connection
on the bottom of the evaporator and/or condenser.
7. To remove all of the moisture from the system and to
insure a leak free unit, pull the system down below 500
microns.
8. 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 difficult.The
oil is aromatic and will give off vapors that will raise
the pressure of the system.
Refrigerant Charging
On RTWD Units, once the system is deemed leak and
moisture free, use the 5/8” flare connections at the bottom
of the evaporator and condenser to add refrigerant charge.
For RTUD Units, once the system is deemed leak and
moisture free, use the service valve on the liquid line to
add refrigerant charge.
See “General Data,” p. 9 and Unit nameplate for
refrigerant charge information.
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
Figure 89. Recommended oil filter replacement
Unit shut down
Minimum system pressure differential
= 25 psid
Clean Filter below this line
Recommend replacing filter
Start protection line for 1st
2.5 minutes of operation
Run protection line after 2.5
minutes of operation
GP2 / RTWD Clean Filter Versus Recommended Filter Replacement
Line
CH530 RTWD Oil Pressure Protection Scheme
NOTICE:
Equipment Damage!
Add field refrigerant charge only through the service
valve on the liquid line, not the service valves on the
evaporator, and insure that water is flowing through the
evaporator during the charging process. Failure to do
the above could result in equipment damage.