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

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

19monitors starter inputs such as line voltage, motor current,ground fault, remote start contact, spare safety, condenser highpressure, oil pump interlock, starter 1M, and run contacts. Itshuts down the chiller if communications with the ICVC arelost. The ISM can also act as the interface for PIC II to the VFDcontroller.The ISM module directly measures current and voltage foreach phase. Calculation of power factor, power in kilowatts,and energy in kilowatt hours is performed by software in theISM for constant speed starters only. All of these values aretransmitted to the ICVC on the SIO (sensor input/output) com-munications bus. The ISM software also defines conditions fortransition for different starter types, and it integrates I2t in mon-itoring motor overload.CHILLER CONTROL MODULE (CCM) — This module islocated in the control panel. The CCM provides the input andoutputs necessary to control the chiller. This module monitorsrefrigerant pressure, entering and leaving water temperatures,and outputs control for the guide vane actuator, oil heaters, andoil pump. The CCM is the connection point for optional de-mand limit, chilled water reset, remote temperature reset, re-frigerant leak sensor and motor kilowatt output.OIL HEATER CONTACTOR (1C) — This contactor is lo-cated in the power panel (Fig. 14) and operates the heater at ei-ther 115 or 230 v. It is controlled by the PIC II to maintain oiltemperature during chiller shutdown. Refer to the control panelwiring schematic.OIL PUMP CONTACTOR (2C) — This contactor is locat-ed in the power panel. It operates all 200 to 575-v oil pumps.The PIC II energizes the contactor to turn on the oil pump asnecessary.HOT GAS BYPASS CONTACTOR RELAY (3C)(OPTIONAL) — This relay, located in the power panel, con-trols the opening of the hot gas bypass valve. The PIC II ener-gizes the relay during low load, high lift conditions.CONTROL TRANSFORMERS (T1, T2) — These trans-formers convert incoming control voltage to 24 vac power forthe 3 power panel contactor relays, CCM, and ICVC.SENSORS — Three types of temperature sensors are used.Figure 15 shows a typical temperature sensor for whichsensor wells are not used, in systems having an ICVC control-ler. For this type, the sensor cable can be easily disconnectedfrom the sensor, which is in direct contact with the fluid.The other typical temperature sensor has sensor wells. SeeFig. 16. For this type, the sensor cable cannot be separatedfrom the sensor itself, but the sensor can be easily removedfrom the well without breaking into the fluid boundry.The third type of temperature sensor is a thermistor, whichis installed either in the motor windings or at the thrust bearingwithin the compressor. Both of these have redundant sensorssuch that if one fails, the other can be connected external to themachine. See Table 2 for a list of standard instrumentation sen-sors.The PIC II control determines refrigerant temperature in thecondenser and evaporator from pressure in those vessels, readfrom the corresponding pressure transducers. See Fig. 14. Thepressure values are converted to the equivalent saturation tem-peratures for R-134a refrigerant. When the chiller is running, ifthe computed value for EVAPORATOR REFRIG TEMP isgreater than, or within 0.6° F (0.33° C) of the LEAVINGCHILLED WATER temperature, its value is displayed as 0.6° F(0.33° C) below LEAVING CHILLED WATER temperature.When the chiller is running, if the computed value for CON-DENSER REFRIG TEMP is less than, or within 1.2° F(0.67° C) of the LEAVING COND WATER temperature, its val-ue is displayed as 1.2° F (0.67° C) above LEAVING CONDWATER temperature.