Vertiv Liebert CRV - Refrigerant Piping Guidelines for Air-Cooled Systems

NOTICE
Risk of improper refrigerant charging. Can cause equipment damage.
Refrigerant charge must be weighed into air-cooled compressorized systems before they are
started. Starting scroll and digital scroll compressors without proper refrigerant charging can
cause the compressors to operate at less than 5°F (–15°C) evaporator temperature and at less
than 20psig (138kPa). Operation for extended periods at less than 20psig (138kPa) can
cause premature compressor failure.
6.1.1 Refrigerant Piping Guidelines for Air-cooled Systems
• 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 Heat-rejection Line Sizes and Equivalent Lengths on page39, for piping sizes.
• Refer to Refrigerant Charge Requirements for Air-cooled Systems on page40, for refrigerant-
charge amounts.
• Refer to condenser installation manual for charging information.
• Install traps on hot gas (discharge) lines at the base of vertical risers and every 15ft (4.6m) of
vertical rise.
• See Piping Layout and Condenser Positioning on page37, for the allowable elevation difference
between the condenser and the Liebert CRV.
• Consult Vertiv™ technical support if piping run exceeds 300feet (91m) 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 air stream of any air conditioner.
• Refrigerant oil – do not mix oil types.
Refer to ASHRAE Refrigeration Handbook for general, good-practice refrigeration piping.
Vertiv | Liebert CRV Installer/User Guide | 35