Refrigerant Connections for Air-Cooled Units
31
Liebert
®
CRV
™
6.0
R
EFRIGERANT
C
ONNECTIONS
FOR
A
IR
-C
OOLED
U
NITS
NOTICE
Risk of oil contamination with water. Can cause equipment damage.
The piping must not be open to the atmosphere for extended periods because the Liebert CRV
requires POE (polyol ester) oil. POE oil absorbs water at a much faster rate when exposed to
air than previously used oils. Because water is the enemy of a reliable refrigeration system,
extreme care must be used when opening systems during installation or service. If water is
absorbed into the POE oil, it will not be easily removed and will not be removed through the
normal evacuation process. If the oil is too wet, it may require an oil change. POE oils also
have a property that makes them act as a solvent in a refrigeration system. Maintaining
system cleanliness is extremely important because the oil will tend to bring any foreign
matter back to the compressor.
The Liebert CRV can be connected to a condenser through either the top or bottom of the unit. The
unit is piped for connections at the top of the unit as shown in
, with provision for
connection through the bottom of the unit.
Connecting through the bottom of the unit requires cutting the liquid and suction lines as shown in
. Cutting these lines disconnects the top connections from the rest of the refrigeration system.
Air-cooled units are shipped with a holding charge of nitrogen.
6.1
Piping Guidelines—Air-Cooled Units
• Indoor unit ships with a nitrogen holding charge; do not vent the evaporator until all refrigerant
piping is in place, ready for connection to the unit and condenser
• Use copper piping with high temperature brazed joints
• Isolate piping from building using vibration-isolating supports
• Refer to
for piping sizes
• Refer to condenser installation manual for charging information
• Install traps on hot gas (discharge) lines at the base of vertical risers and every 15 feet (4.6m) of
vertical rise.
• See
for the allowable elevation difference between the condenser and the Liebert CRV.
• Consult factory if piping run exceeds 300 feet (91m) equivalent length
• Keep piping clean and dry, especially on units with R-410A refrigerant
• Avoid piping runs through noise-sensitive areas
• Do not run piping directly in front of airstream of any air conditioner
• Refrigerant oil – do not mix oil types
Refer to ASHRAE Refrigeration Handbook for general, good-practice refrigeration piping.
!
WARNING
Risk of explosive discharge from high-pressure refrigerant. Can cause injury or death.
This unit contains fluids and/or gases under high pressure.
Relieve pressure before working with piping.