9.4 Electronic Expansion Valve (EEV) Maintenance
The EEV controls superheat through the Liebert® iCOM™ controls by actively measuring suction pressure via a transducer
attached to the suction line rotalock and suction temperature via a thermister strapped to the suction line. The EEV actively
adjusts the orifice size and resulting mass flow of refrigerant to maintain the superheat setpoint (set in Liebert® iCOM™).
The EEV is used in place of the standard thermal expansion valve (TXV).
WARNING! Risk of electric shock. Can cause serious injury or death. The Liebert® iCOM™ microprocessor
does not isolate power from the unit, even in the Unit Off mode. Some internal components require and
receive power even during the unit off mode of the Liebert® iCOM™ control. Open all local and remote electric
power disconnect switches and verify with a voltmeter that power is Off before working on any component of
the system.
NOTE: Intermittent loss of subcooling may result in EEV/superheat instability. If superheat instability is observed,
check for proper refrigerant level in receiver (see Refrigerant Piping Guidelines forAir CooledSystems on page27 for
the proper charge level). If proper charge is observed in receiver, and superheat remains unstable, then increase
superheat setting in the Liebert® iCOM™ to 15°F (8.49°C).
9.5 Compressor Maintenance
WARNING! Risk of over pressurization of the refrigeration system. Can cause explosive discharge of high
pressure refrigerant, loss of refrigerant, environmental pollution, equipment damage, injury, or death. This
unit contains fluids and gases under high pressure. Use extreme caution when charging the refrigerant
system. Do not pressurize the system higher than the design pressure marked on the unit's nameplate.
9.5.1 Compressor Oil
NOTICE
Risk of improper compressor lubrication. Can cause compressor and refrigerant system damage.
Failure to use oil types, viscosities and quantities recommended by the compressor manufacturer may reduce
compressor life and void the compressor warranty.
• Do not mix polyolester (POE) and mineral based oils.
• Do not mix oils of different viscosities.
• Consult Vertiv technical support or the compressor manufacturer if questions arise.
Compressor Type Oil Type
Copeland Scroll and Digital Scroll POE Oil - ISO 32 Centistoke Viscosity
1
1. Use Copeland POE Oil ULTRA 32-3MAF or other Copeland-approved oils.
Source: DPN003950. Rev.5
Table 9.3 Compressor Oil Types for R-410A Refrigerant
9 Maintenance
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