Liebert 83, 205 251, 104 165, 308 415, 1010 manual Refrigeration Piping Connections, Piping Guidelines

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Inspection and Installation

3.9Refrigeration Piping Connections

! WARNING

Risk of explosive discharge from high-pressure refrigerant. Can cause equipment damage, injury or death. Relieve pressure before working with piping.

! WARNING

Risk of refrigerant system rupture or explosion from overpressurization. Can cause equipment damage, injury or death.

If a pressure relief device is not provided with the condenser unit, the system installer must provide and install a discharge pressure relief valve rated for a maximum of 500 psig (34bar) in the high side refrigerant circuit. Do not install a shutoff valve between the compressor and the field installed relief valve.

One or more additional pressure relief valves are required downstream of any and all field installed isolation valves as shown in Figures 2 and 24. Do not isolate any refrigerant circuits from overpressurization protection.

NOTE

POE (polyol ester) oil, required with R407C and used with some R22 systems, is much more hygroscopic than mineral oils. This means that POE oil absorbs water at a much faster rate when exposed to air than previously used mineral 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.

3.9.1Piping Guidelines

Indoor units and condensers both ship with nitrogen holding charges. Do not vent the condenser until all refrigerant piping is in place, ready for connection to indoor unit and condenser.

Use copper piping with a brazing alloy with a minimum temperature of 1350°F (732°C), such as Sil-Fos. Use a flow of dry nitrogen through the piping to prevent the formation of copper oxide scale inside the piping. Avoid soft solders such as 50/50 or 95/5.

Isolate piping from building using vibration isolating supports.

Refer to indoor unit user manual for appropriate piping sizes.

Install traps on the hot gas (discharge) lines at the bottom of any rise over 5 feet high. If the rise exceeds 25 feet (7.5m), then install a trap in 20 foot (6m) increments or evenly divided.

Pitch horizontal hot gas piping at a minimum rate of 1/2" per 10 ft. (42mm per 10m) so that grav- ity will aid in moving oil in the direction of refrigerant/oil flow.

Consult factory if Lee-Temp condenser is located more than 15 ft (4.6m) below the evaporator or if Fan Speed/VFD Control Condenser is located more than 30 ft. (9.2m) below the evaporator.

Consult factory if piping run exceeds 150 feet (46m) equivalent length.

Keep piping clean and dry, especially on units with POE oil (R407C or R22 refrigerant).

Avoid piping runs through noise-sensitive areas.

Do not run piping directly in front of indoor unit discharge airstream.

Refrigerant oil – do not mix oil types or viscosities. Consult indoor unit for refrigerant type and oil requirements.

NOTE

Failure to use compressor oils recommended by compressor manufacturer will void compressor warranty. Consult Liebert or compressor manufacturer for further recommendations or if you have questions about compressor oils.

Refer to ASHRAE Refrigeration Handbook for general good practices for refrigeration piping.

A pressure relief valve is provided with Liebert Lee-Temp condensers. A fusible plug is provided on Liebert Fan Speed Control and VFD condensers. The Liebert indoor cooling unit has a factory-installed high-pressure safety switch in the high side refrigerant circuit.

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Contents Liebert Air Cooled, Direct Drive Condensers On condensers with VFD Control, Lee-temp receivers, Three-phase voltage is only voltage available as standardExample DCDF165-Y Fan Speed Control 2-8 fan models onlyTable of Contents System Maintenance OperationFan Speed Product Description and FeaturesHead Pressure Control Types Variable Frequency DriveTypical System Configurations Sound Level OptionsTransient Voltage Surge Suppression Option Fan Speed and VFD Lee-Temp DischargeDimensions and Weights Site ConsiderationsSee for typical condenser footprint dimensions 1067 mmFour-Fan41-3/16 Condenser 1046mm Operation and component access Condenser footprint dimensionsSee for typical Typical condenser footprint-dimensions Piping connections for 6- and 8-fan Fan Speed Condensers Site Preparation Condenser physical data Quiet-Line ModelsReceiver Refrigerant Planning ValuesR-407C refrigerant required, approximate Quiet-Line Condenser ModelsEquipment Inspection Packing MaterialHandling Unit on the Skid Unpacking the UnitRemoving the Skid and Attaching Slings Attaching legs to a 6-fan or 8-fan unit StepMounting the Condenser Attaching sling to a 6-fan or 8-fan unit for movingLine Voltage Wiring Electrical Supply Preparation60Hz condenser data 50Hz condenser full load amp valuesElectrical Connections Low Voltage Control WiringLow Voltage Monitoring Wiring-TCDV Only Lee-Temp receiver electrical data, 50Hz and 60HzWye-Connected Power Supply Delta-Connected Power SupplyVFD Control Condensers Tcdv only Disconnect EMC Filter for Delta-Connected Power Electric service connection and fuse block Electrical Field Connection DescriptionsElectrical field connections for VFD control condensers Inspection and Installation Refrigeration Piping Connections Piping GuidelinesField Piping Installation VFD and Fan Speed Control condenser pipingLee-Temp head pressure control condenser piping Single Circuit Shown General arrangement-Air cooled models with Lee-Temp controlSystem Dehydration/Leak Test and Charging Procedures Piping Moving and Placing EquipmentElectrical OtherStartup Checklist StartupGeneral Procedures System MaintenanceWhen to Clean Special ProceduresCondenser Cleaning How to CleanCondenser Electrical Panel Condenser Electric Panel Maintenance Inspection ChecklistMonthly Semiannually Condenser Fan MotorsTroubleshooting Symptom Possible Cause Check or RemedySystem Maintenance System Maintenance Page Ti n Ne tIti That