Carrier AquaEdge 19XRV series Operation, Maintenance And Installation 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

93TROUBLESHOOTING GUIDE(TABLES 15-18B)Overview — The PIC III has many features to help theoperator and technician troubleshoot a 19XRV chiller.• The ICVC shows the chiller’s actual operating conditionsand can be viewed while the unit is running.• The ICVC default screen freezes when an alarm occurs. Thefreeze enables the operator to view the chiller conditions atthe time of alarm. The STATUS screens continue to showcurrent information. Once all alarms have been cleared (bycorrecting the problems and pressing the softkey),the ICVC default screen returns to normal operation.• The CONTROL ALGORITHM STATUS screens (whichinclude the CAPACITY, OVERRIDE, LL_MAINT,VFD_HIST, LOADSHED, CUR_ALARM, WSM-DEFME, and OCCDEFCM screens) display informationthat helps to diagnose problems with chilled water tempera-ture control, chilled water temperature control overrides, hotgas bypass, surge algorithm status, and time schedule opera-tion. See Table 15.• The control test feature facilitates the proper operation andtest of temperature sensors, pressure transducers, the guidevane actuator, oil pump, water pumps, tower control, andother on/off outputs while the compressor is stopped. It alsohas the ability to lock off the compressor and turn on waterpumps for pumpout operation. The ICVC shows the tem-peratures and pressures required during these operations.• From other SERVICE tables, the operator/technician canaccess configured items, such as chilled water resets, over-ride set points, etc.• If an operating fault is detected, an alarm message is gener-ated and displayed on the ICVC default screen. A moredetailed message — along with a diagnostic message — isalso stored into the ALARM HISTORY and ALERT HIS-TORY tables.• Review the ALERT HISTORY table to view other less crit-ical events and abnormal conditions which may haveoccurred. Compare timing of relevant alerts and alarms.Checking Display Messages — The first area tocheck when troubleshooting the 19XRV is the ICVC display. Ifthe alarm light is flashing, check the primary and secondarymessage lines on the ICVC default screen (Fig. 18). Thesemessages will indicate where the fault is occurring. Thesemessages contain the alarm message with a specified code. Fora complete list of possible alarm and alert messages, seeTable 16. This code or state appears with each alarm and alertmessage. The ALARM and ALERT HISTORY tables on theICVC SERVICE menu also contains a message to furtherexpand on the fault description. For a complete list of VFDFault Code Descriptions and corrective actions, see Table 17.NOTE: The date format in these tables is MM/DD/YY.If the alarm light starts to flash while accessing a menuscreen, press the softkey to return to the default screento read the alarm message. The STATUS screen can also be ac-cessed to determine where an alarm exists.A “C” to the right of a parameter’s value means that there isa communications fault on that channel.Checking Temperature Sensors — All tempera-ture sensors are thermistor-type sensors. This means that theresistance of the sensor varies with temperature. All sensorshave the same resistance characteristics. If the controls are on,determine sensor temperature by measuring voltage drop; if thecontrols are powered off, determine sensor temperature bymeasuring resistance. Compare the readings to the values listedin Table 18A or 18B.RESISTANCE CHECK — Turn off the control power and,from the module, disconnect the terminal plug of the sensor inquestion. With a digital ohmmeter, measure sensor resistancebetween receptacles as designated by the wiring diagram. Theresistance and corresponding temperature are listed inTable 18A or 18B. Check the resistance of both wires toground. This resistance should be infinite.VOLTAGE DROP — The voltage drop across any energizedsensor can be measured with a digital voltmeter while thecontrol is energized. Table 18A or 18B lists the relationshipbetween temperature and sensor voltage drop (volts dcmeasured across the energized sensor). Exercise care whenmeasuring voltage to prevent damage to the sensor leads,connector plugs, and modules. Sensors should also be checkedat the sensor plugs. Check the sensor wire at the sensor for5 vdc if the control is powered on.CHECK SENSOR ACCURACY — Place the sensor in amedium of known temperature and compare that temperatureto the measured reading. The thermometer used to determinethe temperature of the medium should be of laboratory qualitywith 0.5 F (.25 C) graduations. The sensor in question shouldbe accurate to within 2 F (1.2 C).See Fig. 12 for sensor locations. The sensors are immerseddirectly in the refrigerant or water circuits. The wiring at eachsensor is easily disconnected by unlatching the connector.These connectors allow only one-way connection to the sensor.When installing a new sensor, apply a pipe sealant or threadsealant to the sensor threads.DUAL TEMPERATURE SENSORS — For servicing con-venience, there are 2 sensors each on the bearing and motortemperature sensors. If one of the sensors is damaged, the othercan be used by simply moving a wire. The number 2 terminalin the sensor terminal box is the common line. To use thesecond sensor, move the wire from the number 1 position to thenumber 3 position.Checking Pressure Transducers — There are 6factory-installed pressure transducers, with inputs available foroptional cooler and condenser waterside differential pressuretransducers. The ICVC software will display a default readingof 26 psi during start-up and operation. An additional transduc-er, factory installed in the bottom of the cooler barrel, will readas EVAPORATOR SATURATION TEMP on the HEAT_EXCONTACTORTERMINALSTRIP FUSESTRANSFORMERSWITCHFig. 54 — Pumpout Control Box (Interior)a19-1569RESETCAUTIONRelieve all refrigerant pressure or drain the water beforereplacing temperature sensors or thermowells threaded intothe refrigerant pressure boundary. Failure to do so couldresult in personal injury and equipment damage.EXIT