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

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Carrier AquaEdge 19XR series Start-up, Operation And Maintenance Instructions Manual Manual pdf 94 page image

94from concentration of refrigerant to keep false readings to aminimum. Before making any necessary repairs to a leak,transfer all refrigerant from the leaking vessel.Leak Rate — It is recommended by ASHRAE that chillersbe taken off line immediately and repaired if the refrigerantleak rate for the entire chiller is more than 10% of the operatingrefrigerant charge per year.In addition, Carrier recommends that leaks totalling lessthan the above rate but more than a rate of 0.1% of the totalcharge per year should be repaired during annual maintenanceor whenever the refrigerant is transferred for other servicework.Test After Service, Repair, or Major Leak — If allthe refrigerant has been lost or if the chiller has been openedfor service, the chiller or the affected vessels must be pressuretested and leak tested. Refer to the Leak Test Chiller section toperform a leak test.TESTING WITH REFRIGERANT TRACER — Use an en-vironmentally acceptable refrigerant as a tracer for leak testprocedures. Use dry nitrogen to raise the machine pressure toleak testing levels.TESTING WITHOUT REFRIGERANT TRACER — An-other method of leak testing is to pressurize with nitrogen onlyand to use a soap bubble solution or an ultrasonic leak detectorto determine if leaks are present.TO PRESSURIZE WITH DRY NITROGENNOTE: Pressurizing with dry nitrogen for leak testing shouldnot be done if the full refrigerant charge is in the vesselbecause purging the nitrogen is very difficult.1. Connect a copper tube from the pressure regulator on thecylinder to the refrigerant charging valve. Never applyfull cylinder pressure to the pressurizing line. Follow thelisted sequence.2. Open the charging valve fully.3. Slowly open the cylinder regulating valve.4. Observe the pressure gage on the chiller and close theregulating valve when the pressure reaches test level. Donot exceed 140 psig (965 kPa).5. Close the charging valve on the chiller. Remove the cop-per tube if it is no longer required.Repair the Leak, Retest, and Apply StandingVacuum Test — After pressurizing the chiller, test forleaks with an electronic halide leak detector, soap bubble solu-tion, or an ultrasonic leak detector. Bring the chiller back to at-mospheric pressure, repair any leaks found, and retest.After retesting and finding no leaks, apply a standing vacu-um test. Then dehydrate the chiller. Refer to the Standing Vacu-um Test and Chiller Dehydration section (page 71) in the Be-fore Initial Start-Up section.Checking Guide Vane Linkage — When the chilleris off, the guide vanes are closed and the actuator mechanism isin the position shown in Fig. 49. Slack in the guide vane actua-tor’s drive chain can only be removed with the guide vaneactuator fully closed and the chiller shut down. Complete thefollowing steps to adjust chain tension and position:1. Remove the two set screws in the guide vane actuatorsprocket.2. Loosen the guide vane actuator’s holddown bolts.3. Pull the guide vane actuator away from the suction hous-ing along the slotted holes in the actuator bracket.4. Rotate the guide vane sprocket fully clockwise andspot-drill the guide vane actuator shaft. Spot-drilling isnecessary when the guide vane actuator sprocket setscrews on the guide vane actuator shaft need to bere-seated. (Remember: Spot-drill and tighten the first setscrew before spot-drilling for the second set screw.)WARNINGHFC-134a should not be mixed with air or oxygen andpressurized for leak testing. In general, this refrigerantshould not be present with high concentrations of air oroxygen above atmospheric pressures, because the mixturecan undergo combustion.CHAINGUARDDRIVECHAINGUIDE VANEACTUATORSPROCKETSETSCREWSGUIDE VANEACTUATORSUCTIONHOUSINGGUIDE VANEACTUATORSHAFTACTUATORBRACKETHOLDDOWNBOLTS (3)GUIDE VANESHAFTGUIDE VANESPROCKETOPENCLOSEFig. 49 — Guide Vane Actuator Linkagea19-1731