Emerson Figure i General, Compressor Failure, Electrical Failure-Burnout, Mechanical Failure

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Maintenance

4.0MAINTENANCE

4.1General

Access the condensing unit by removing the unit housing panel. Clean the air cooled condenser coil of all debris that will inhibit airflow. This can be done with compressed air or with a commercial coil cleaner. Check for bent or damaged coil fins and repair as necessary. During winter, do not permit snow to accumulate on or around the condensing unit. Check all refrigerant lines and capillaries for vibration isolation and support as necessary. Check all refrigerant lines for signs of leaks.

! WARNING

Turn Off power to unit at disconnect switch unless you are performing tests that require power. With power and controls energized, unit could begin operating automatically at any time.

! WARNING

Hazardous voltage will still be present at condenser even with power turned Off at the control panel. To isolate unit for maintenance, turn the unit Off at disconnect switch.

! CAUTION

If condenser power is disconnected for a long period, do not attempt to start the condensing unit until 8 hours after restoring power. This allows time for liquid refrigerant to be driven out of the compressor. This is especially important at low ambient temperatures.

4.2Compressor Failure

If a compressor motor burns out, the stator wiring insulation decomposes, forming carbon, water and acid. Not only must the compressor be replaced, but the entire refrigeration circuit must be cleaned of the harmful contaminants left by the burnout. Successive burnouts of the same system can usually be attributed to improper system cleaning.

! WARNING

Damage to a replacement compressor caused by improper system cleaning constitutes abuse under the terms of the warranty.

Before proceeding with a suspected burnout, check all electrical components: fuses, contactors and wiring. Check high-pressure switch operation. If a compressor failure has occurred, determine whether it is an electrical or mechanical failure. An electrical failure will be indicated by a distinct, pungent odor. If a severe burnout has occurred, the oil will be black and acidic. In the case of a mechanical failure, there will be no burn odor and the motor will attempt to run.

4.2.1Electrical Failure—Burnout

In the event that there is an electrical failure and a complete burnout of the refrigeration compressor motor, the proper procedures must be performed in order to clean the system to remove any acids that would cause a future failure.

NOTE

Failure to properly clean the system after a compressor motor burnout will void the compressor warranty. Follow the manufacturer’s procedure.

! CAUTION

Avoid touching or contacting the gas and oils with exposed skin. Severe burns may result. Use long rubber gloves in handling contaminated parts.

4.2.2Mechanical Failure

If a mechanical failure has occurred, the compressor must be replaced.

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Contents Liebert Prop Fan Condensing Unit Example PFH037A-PL7 = 380/415-3ph-50HzTable of Contents Figures Prop Fan Condensing Units Optional EquipmentEquipment Inspection Location ConsiderationsDimensional Data Net WeightModel Numbers Dimensional Data, in. mm Lb. kg 60Hz 50Hz Cabinet and floor planning data, horizontal air dischargeFootprint Dimensions Wall Mounting Piping and Electrical Connections Electrical and piping connections, horizontal air discharge152 PFH096A- LGeneral piping arrangement Electrical field connections, 1- to 5-ton units Top Air Discharge ModelsElectrical field connections, 8-ton units Single-phase, 1-3 ton model schematic, typical Three-phase, 3-5 ton model schematic, typical Three-phase, 8 ton model schematic, typical Piping Considerations Piping for Elevation Differences between PFH and EvaporatorEquivalent lengths for various pipe fittings, ft m EvaporatorCondensing Unit Pre-Charged Line Sets Field-Fabricated Line SetsRefrigerant charge in Liebert pre-charged R-407C line sets Line Size Length Charge R-407C Ft. m Lb-oz kgLiebert PFH unit charge levels and coupling size Recommended line sizes, OD CuInstallation of Piping to Units Piping connection sizes and torqueLine charges refrigerant per 100 ft m of Type L copper tube Line Size OD Cu Coupling Size Torque, lb-ft. N-mRemove Existing Condensing Unit Filter Drier Selection and InstallationInstall the New Condensing Unit Evaporator Charge R-407C Indoor Unit Models Oz kg General System Charge RequirementsEvaporator Charge Levels Electrical Connections Low-Voltage Control Wire ConnectionsLow-Voltage Control Wire Sizing Nominal Input Voltage- Phase Capacity Electrical Nominal Input Voltage-Phase Capacity ElectricalElectrical Data Electrical data-High ambient models 105F/41C 60HzElectrical data-Quiet-Line models 95F/35C 60Hz Electrical data-High ambient models 105F/41C 50HzChecklist for Completed Installation Electrical data Quiet-Line models 95F/35C 50HzLiebert Lee-Temp Flood Back Head Pressure Control CompressorHigh Head Pressure Operation AdjustmentHot Gas Bypass Hot gas bypass diagram General Compressor FailureElectrical Failure-Burnout Mechanical FailureCompressor Replacement Model Numbers 407C 60 Hz 50 Hz Oz kg Field Charge VerificationField verification charge Troubleshooting Problem Cause RemedySingle-Phase&Three-Phase UPS Environmental Systems Web Site MonitoringUni Etwo
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