Liebert PW017 User Manual

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.
5.2.1 Refrigerant Piping Guidelines forAir-cooledSystems
• Air-cooled units ship 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 a brazing alloy with a minimum temperature of 1350°F (732°C), such as
Sil-Fos. Avoid soft solders, such as 50/50 or 95/5.
• Use a flow of dry nitrogen through the piping during brazing to prevent formation of copper
oxide scale inside the piping. When copper is heated in the presence of air, copper oxide forms.
POE oils will dissolve these oxides from inside the copper pipes and deposit them throughout
the system, clogging filter driers and affecting other system components.
• A pure dry nitrogen flow of 1-3 ft
3
/min (0.5-1.5 l/s) inside the pipe during brazing is sufficient to
displace the air. Control the flow using a suitable measuring device.
• Ensure that the tubing surfaces to be brazed are clean and that all burrs have been removed
from the ends of the tubes.
• Ensure that all loose material has been cleaned from inside the tubing before brazing.
• Protect all refrigerant line components within 18in. (460mm) of the brazing site by wrapping
them with a wet cloth or with a suitable heat-sink compound.
• Isolate piping from building using vibration-isolating supports.
• Refer to Refrigerant Line Sizes and Equivalent Lengths on the next page for recommended
refrigerant piping sizes based on equivalent pipe lengths.
• Refer to Refrigerant Charge Requirements for Air-cooled Systems on the next page, for
refrigerant-charge amounts.
• Refer to condenser user manual for charging information.
• Condensers with receivers cannot be installed below the evaporator. The maximum height of
the condenser above the evaporator is 60ft (18.3m).
Consult the factory before installing units, condensers, and receivers outside these parameters.
• Install traps on hot-gas (discharge) lines at the base of vertical risers over 5ft(1.5m) and every
20ft(6m) for vertical rises over 25 ft (7.6m), then install a trap in 20-ft (6-m) increments or
evenly-divided over the vertical rise.
• Pitch horizontal hot-gas piping down at a minimum rate of 1/2in.per 10ft (42mm per 10m) so
that gravity will aid in moving oil in the direction of refrigerant/oil flow.
• Units with an Electronic Expansion Valve (EEV) must have EEV mounted below the receiver
liquid outlet.
• Consult factory if piping run exceeds 300ft (91m) equivalent length.
• Keep piping clean and dry, especially on units with R-410A refrigerant.
• Avoid piping runs through noise-sensitive areas.
Vertiv | Liebert® PDX™ and PCW™ Installer/User Guide | 35

Liebert PW017 Specifications

General

Brand	Liebert
Model	PW017
Category	Control Unit
Language	English