Carrier 19XRV Start-up, Operation And Maintenance Instructions Manual

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

Contents

14CONTROLSDefinitionsANALOG SIGNAL — An analog signal varies in proportionto the monitored source. It quantifies values between operatinglimits. (Example: A temperature sensor is an analog device be-cause its resistance changes in proportion to the temperature,generating many values.)DISCRETE SIGNAL — A discrete signal is a 2-position rep-resentation of the value of a monitored source. (Example: Aswitch produces a discrete signal indicating whether a value isabove or below a set point or boundary by generating an on/off,high/low, or open/closed signal.)General — The 19XRV hermetic centrifugal liquid chillercontains a microprocessor-based control panel that monitorsand controls all operations of the chiller. See Fig. 8 and 9. Themicroprocessor control system matches the cooling capacity ofthe chiller to the cooling load while providing state-of-the-artchiller protection. The system controls the cooling load withinthe set point plus the deadband by sensing the leaving chilledwater or brine temperature and regulating the inlet guide vanevia a mechanically linked actuator motor. The guide vane is avariable flow pre-whirl assembly that controls the refrigerationeffect in the cooler by regulating the amount of refrigerantvapor flow into the compressor. An increase in guide vaneopening increases capacity. A decrease in guide vane openingdecreases capacity. The microprocessor-based controls protectthe chiller by monitoring the digital and analog inputs andexecuting capacity overrides or safety shutdowns, if required.PIC III System Components — The chiller controlsystem is called the PIC III (Product Integrated Control III).See Table 1. The PIC III controls the operation of the chiller bymonitoring all operating conditions. The PIC III can diagnose aproblem and let the operator know what the problem is andwhat to check. It promptly positions the guide vanes tomaintain leaving chilled water temperature. It can interfacewith auxiliary equipment such as pumps and cooling towerfans to turn them on when required. It continually checks allsafeties to prevent any unsafe operating condition. It also regu-lates the oil heater while the compressor is off and regulates thehot gas bypass valve, if installed. The PIC III controls providecritical protection for the compressor motor and controls theVFD. The PIC III can interface with the Carrier ComfortNetwork® (CCN) system if desired. It can communicate withother PIC I, PIC II, or PIC III equipped chillers and other CCNdevices.The PIC III consists of 3 modules housed inside 3 majorcomponents. The component names and corresponding controlvoltages are listed below (also see Table 1):• control panel— all extra low-voltage wiring (24 v or less)• power panel— 115 vac control voltage (per job requirement)— 115 vac power for oil heater and actuators— up to 460 vac for oil pump power• VFD cabinet— chiller power wiring (per job requirement)Table 1 — Major PIC III Components andPanel Locations**See Fig. 5-11.PIC III COMPONENT PANEL LOCATIONInternational Chiller Visual Controller(ICVC) and DisplayControl PanelChiller Control Module (CCM) Control PanelControl Transformer Circuit BreakersCB1, CB2Control PanelOil Heater Contactor (1C) Power PanelOil Pump Contactor (2C) Power PanelHot Gas Bypass Relay (3C) (Optional) Power PanelControl Transformers (T1, T2, T3) Power PanelTemperature Sensors See Fig. 8.Pressure Transducers See Fig. 8.COOLER CHARGINGVALVE (HIDDEN)CONTROLPANELSPLIT RINGDIFFUSERACTUATOR(OPTIONAL)GUIDE VANEACTUATOR OIL SUMPPRESSURETRANSDUCER POWERPANELOIL SUMPTEMPERATURESENSOROIL PUMPDISCHARGEPRESSUREWATERSENSORCABLESHGBPACTUATOR(OPTIONAL)VFD COOLINGSOLENOIDVFD ENCLOSUREEVAPORATOR SATURATIONTEMPERATURE SENSOR(ON BOTTOM OF COOLER)CONDENSER CHARGINGVALVE (HIDDEN)CONDENSER3-WAY SHUTOFFVALVECONDENSERPRESSURETRANSDUCERWATERSENSORCABLESCOOLERPRESSURETRANSDUCERFig. 8 — Chiller Controls and Sensor Locationsa19-1730