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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26Refrigerant TracerCarrier recommends the use of an environmentally acceptablerefrigerant tracer for leak testing with an electronic detector.Ultrasonic leak detectors can also be used if the chiller is underpressure.Leak Test ChillerDue to regulations regarding refrigerant emissions and the diffi-culties associated with separating contaminants from the refriger-ant, Carrier recommends the following leak test procedure. Referto Tables 6 and 7 for refrigerant pressure/temperature values.1. If the pressure readings are normal for the chiller condition:a. Evacuate the holding charge from the vessels, if present.b. Raise the chiller pressure, if necessary, by addingrefrigerant until pressure is at the equivalent saturatedpressure for the surrounding temperature. Followpumpout procedures in the Transfer Refrigerant fromPumpout Storage Tank to Chiller section, Steps 1a-e,page 44.c. Leak test chiller as outlined in Steps 3 to 9.2. If the pressure readings are abnormal for the chiller condition:a. Prepare to leak test chillers shipped with refrigerant(Step 2h).b. Check for large leaks by connecting a nitrogen bottleand raising the pressure to 30 psig (207 kPa). Soaptest all joints. If the test pressure holds for 30 minutes,prepare the test for small leaks (Steps 2g and 2h).c. Plainly mark any leaks that are found.d. Release the pressure in the system.e. Repair all leaks.f. Retest the joints that were repaired.g. After successfully completing the test for large leaks,remove as much nitrogen, air, and moisture as possi-ble, given the fact that small leaks may be present inthe system. This can be accomplished by followingthe dehydration procedure outlined in the ChillerDehydration section, page 28.h. Slowly raise the system pressure to a maximum of160 psig (1103 kPa) but no less than 35 psig(241 kPa) for HFC-134a by adding refrigerant (below35 psig refrigerant must be added as a gas). Proceedwith the test for small leaks (Steps 3 to 9).3. Check the chiller carefully with an electronic leak detectoror soap bubble solution.4. Leak Determination — If an electronic leak detector indicatesa leak, use a soap bubble solution, if possible, to confirm.Total all leak rates for the entire chiller. Leakage at ratesgreater than 0.1% of the total charge per year must berepaired. Note the total chiller leak rate on the start-up report.5. If no leak is found during the initial start-up procedures,complete the transfer of refrigerant gas from the storagetank to the chiller. Retest for leaks.6. If no leak is found after a retest:a. Transfer the refrigerant to the storage tank and per-form a standing vacuum test as outlined in the Stand-ing Vacuum Test section, below.b. If the chiller fails the standing vacuum test, check forlarge leaks (Step 2b).c. If the chiller passes the standing vacuum test, dehy-drate the chiller. Follow the procedure in the ChillerDehydration section, page 28. Charge the chiller withrefrigerant.7. If a leak is found after a retest, pump the refrigerant backinto the storage tank or, if isolation valves are present,pump the refrigerant into the non-leaking vessel. See theTransfer Refrigerant from Pumpout Storage Tank toChiller section on page 44.8. Transfer the refrigerant until the chiller pressure is at18 in. Hg (40 kPa absolute).9. Repair the leak and repeat the procedure, beginning fromStep 2h, to ensure a leak-tight repair. (If the chiller isopened to the atmosphere for an extended period, evacuateit before repeating the leak test.)Standing Vacuum TestWhen performing the standing vacuum test or chiller dehydration,use a manometer or a digital vacuum gage. Dial gages cannot indi-cate the small amount of acceptable leakage during a short periodof time.1. Attach an absolute pressure manometer or digital vacuumgage to the chiller.2. Evacuate the vessel to at least 18 in. Hg vac (41 kPa[abs]), using a vacuum pump or the pumpout unit.3. Valve off the pump to hold the vacuum and record themanometer or indicator reading.4. Check the leakage rate.a. If the leakage rate is less than 0.05 in. Hg (0.17 kPa)in 24 hours, the chiller is sufficiently tight.b. If the leakage rate exceeds 0.05 in. Hg (0.17 kPa) in24 hours, re-pressurize the vessel and test for leaks ifrefrigerant is available. If not, use nitrogen and arefrigerant tracer. Raise the vessel pressure in incre-ments until the leak is detected. If refrigerant is used,the maximum gas pressure is approximately 70 psig(483 kPa) for HFC-134a at normal ambient tempera-ture. If nitrogen is used, limit the leak test pressure to160 psig (1103 kPa) maximum.5. Repair the leak, retest, and proceed with dehydration.WARNINGDo not use air or oxygen as a means of pressurizing the chiller.Mixtures of HFC-134a and air can undergo combustion, re-sulting in equipment damage and possible personal injury.CAUTIONNever charge liquid refrigerant into the chiller if the pressurein the chiller is less than 35 psig (241 kPa) for HFC-134a orless than 39 psig (268 kPa) for R-513A. Charge as a gas only,with the cooler and condenser pumps running, until this pres-sure is reached, using PUMPDOWN/LOCKOUT (located inthe Maintenance menu) and TERMINATE LOCKOUT modeon PIC 6 control interface. Flashing of liquid refrigerant at lowpressures can cause tube freeze-up and considerable damage.