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

Also see for AquaEdge 19XR: Controls operation and troubleshooting Start-up, operation and maintenance instructions Start-up, operation and maintenance instructions

Carrier AquaEdge 19XR Start-up, Operation And Maintenance Instructions Manual Manual pdf 32 page image

32After Extended ShutdownEnsure the water system drains are closed. It may be advisableto flush the water circuits to remove any soft rust that may haveformed. This is a good time to brush the tubes and inspect theSchrader fittings on the waterside flow devices for fouling, ifnecessary.Check the cooler pressure on the HMI panel and compare it tothe original holding charge that was left in the chiller. If (afteradjusting for ambient temperature changes) any loss in pres-sure is indicated, check for refrigerant leaks. See Check ChillerTightness section, page 13.Recharge the chiller by transferring refrigerant from the pumpoutstorage tank (if supplied). Follow the Pumpout and RefrigerantTransfer Procedures section. Observe freeze-up precautions.Carefully make all regular preliminary and running systemchecks. If the compressor oil level appears abnormally high,the oil may have absorbed refrigerant. Ensure that the oil tem-perature is above 40°F (4.4°C) or above the EVAP SAT TEMPplus 50F (27C).Cold Weather OperationWhen the entering condenser water temperature drops verylow, the operator should automatically cycle the cooling towerfans off to keep the temperature up. Piping may also be ar-ranged to bypass the cooling tower.Manual Guide Vane OperationIt is possible to manually operate the guide vanes in order tocheck control operation or to control the guide vanes in anemergency. Manual operation is possible by overriding the tar-get guide vane position.NOTE: Manual control overrides the configured pulldown rateduring start-up and permits the guide vanes to open at a fasterrate. Motor current above the electrical demand setting, capaci-ty overrides, and chilled water temperature below the controlpoint override the manual target and close the guide vanes. Fordescriptions of capacity overrides and set points, see the 19XRwith PIC 5 Controls Operation and Troubleshooting guide.Refrigeration LogA refrigeration log (as shown in Fig. 26), is a convenientchecklist for routine inspection and maintenance and providesa continuous record of chiller performance. It is also an aidwhen scheduling routine maintenance and diagnosing chillerproblems.Keep a record of the chiller pressures, temperatures, and liquidlevels on a sheet similar to the one in Fig. 26. Automatic re-cording of data is possible by using CCN devices such as theData Collection module and a Building Supervisor. Contact aCarrier representative for more information.PUMPOUT AND REFRIGERANTTRANSFER PROCEDURESPreparationThe 19XR chiller may come equipped with an optional pumpoutstorage tank, pumpout system, or pumpout compressor. The re-frigerant can be pumped for service work to either the chillercompressor vessel or chiller condenser vessel by using the op-tional pumpout system. If a pumpout storage tank is supplied,the refrigerant can be isolated in the storage tank. The followingprocedures describe how to transfer refrigerant from vessel tovessel and perform chiller evacuation.IMPORTANT: A field-supplied water temperature controlsystem for condenser water should be installed. The systemshould maintain the leaving condenser water temperature ata temperature that is at least 20F (11C) above the leavingchilled water temperature.CAUTIONThe power to the pumpout compressor oil heater must beon whenever any valve connecting the pumpout compres-sor to the chiller or storage tank is open. Leaving the heateroff will result in oil dilution by refrigerant and can lead tocompressor failure.If the compressor is found with the heater off and a valveopen, the heater must be on for at least 4 hours to drive therefrigerant from the oil. When heating the oil the compres-sor suction must be open to a vessel to give the refrigerant ameans to leave the compressor.CAUTIONAlways run the chiller cooler and condenser water pumpsand always charge or transfer refrigerant as a gas when thechiller pressure is less than 35 psig (241 kPa). Below thesepressures, liquid refrigerant flashes into gas, resulting in ex-tremely low temperatures in the cooler/condenser tubes andpossibly causing tube freeze-up.