Carrier AquaEdge 19XR Series Start-up, Operation And Maintenance Instructions Manual

Also see for AquaEdge 19XR series: Installation instructions Start-up, operation and maintenance instructions

Contents

51ECONOMIZER DAMPER VALVEThe damper valve operation should be inspected annually (exter-nal inspection) and internally when the refrigerant is removed andit has been more than 5 years since last inspection or initial start-up. See Fig. 52 for economizer damper valve detail.Fig. 52 — Economizer Damper Valve (Two-StageCompressor Chiller)Inspect Relief Valves and PipingThe relief valves on this chiller protect the system against the po-tentially dangerous effects of overpressure. To ensure againstdamage to the equipment and possible injury to personnel, thesedevices must be kept in peak operating condition.As a minimum, the following maintenance is required.1. At least once a year, disconnect the vent piping at thevalve outlet and carefully inspect the valve body andmechanism for any evidence of internal corrosion or rust,dirt, scale, leakage, etc.2. If corrosion or foreign material is found, do not attempt torepair or recondition. Replace the valve.3. If the chiller is installed in a corrosive atmosphere or therelief valves are vented into a corrosive atmosphere,inspect the relief valves at more frequent intervals.Compressor Bearing and Gear MaintenanceThe key to good bearing and gear maintenance is proper lubrica-tion. Use the proper grade of oil, maintained at recommended lev-el, temperature, and pressure. Inspect the lubrication system regu-larly and thoroughly. Annual oil analysis and vibration measure-ments are recommended.Excessive bearing wear can sometimes be detected through in-creased vibration or increased bearing temperature. Gears, bab-bitted journal bearings, and thrust bearings should be examinedfor signs of wear based on the results of the annual oil analysisand vibration levels. To inspect the bearings, a complete com-pressor teardown is required. Only a trained service technicianshould remove and examine the bearings. The frequency of ex-amination is determined by the hours of chiller operation, loadconditions during operation, and the condition of the oil and thelubrication system. High speed shaft rolling element bearingscannot be field inspected; excessive vibration is the primary signof wear or damage. If either symptom appears, contact an expe-rienced and responsible service organization for assistance.Inspect the Heat Exchanger Tubes andFlow DevicesCOOLER AND OPTIONAL FLOW DEVICESInspect and clean the cooler tubes at the end of the first operatingseason. Confirm that there is no foreign debris from the systemthat could have lodged in the tubes potentially resulting in tubefailure. Because these tubes have internal ridges, a rotary-typetube cleaning system is needed to fully clean the tubes. Inspect thetubes’ condition to determine the scheduled frequency for futurecleaning and to determine whether water treatment in the chilledwater/brine circuit is adequate. Inspect the entering and leavingchilled water temperature sensors and flow devices for signs ofcorrosion or scale. Replace a sensor or Schrader fitting if corrodedor remove any scale if found.CONDENSER AND OPTIONAL FLOW DEVICESSince this water circuit is usually an open-type system, the tubesmay be subject to contamination and scale. Clean the condensertubes with a rotary tube cleaning system at least once per year andmore often if the water is contaminated. Confirm that there is noforeign debris from the system that could have lodged in the tubespotentially resulting in tube failure. Inspect the entering and leav-ing condenser water sensors and flow devices for signs of corro-sion or scale. Replace the sensor or Schrader fitting if corroded orremove any scale if found.Higher than normal condenser pressures, together with the inabili-ty to reach full refrigeration load, usually indicate dirty tubes or airin the chiller. If the refrigeration log indicates a rise above normalcondenser pressures, check the condenser refrigerant temperatureagainst the leaving condenser water temperature. If this reading ismore than what the design difference is supposed to be, the con-denser tubes may be dirty or water flow may be incorrect. BecauseHFC-134a is a high-pressure refrigerant, air usually does not enterthe chiller.During the tube cleaning process, use brushes specially de-signed to avoid scraping and scratching the tube wall. Contactyour Carrier representative to obtain these brushes. Do not usewire brushes.Hard scale may require chemical treatment for its prevention or re-moval. Consult a water treatment specialist for proper treatment.Water LeaksThe refrigerant moisture indicator on the refrigerant motor coolingline (Fig. 3-5) indicates whether there is water leakage duringchiller operation. Water leaks should be repaired immediately.Water TreatmentUntreated or improperly treated water may result in corrosion,scaling, erosion, or algae. The services of a qualified water treat-ment specialist should be obtained to develop and monitor a treat-ment program.Inspect the Starting Equipment or VFDBefore working on any starter, shut off the chiller, open and tag alldisconnects supplying power to the starter.SPRINGHOUSINGCONNECTIONTO COOLERO-RINGECONOMIZERSIDECOMPRESSORSIDEVALVEPACKINGCAUTIONThe chiller must be dehydrated after repair of water leaks ordamage may result. See Chiller Dehydration section, page 28.CAUTIONWater must be within design flow limits, clean, and treated toensure proper chiller performance and reduce the potential oftube damage due to corrosion, scaling, erosion, and algae.Carrier assumes no responsibility for chiller damage result-ing from untreated or improperly treated water.