Carrier 38APS025 Manual

Also see for 38APD115: Installation instructions

Carrier 38APS025 Manual Manual pdf 162 page image

162TROUBLESHOOTINGTable 78 is an abbreviated list of symptoms, probablecauses, and potential remedies.Alarms and Alerts — These are warnings of abnormalor fault conditions, and may cause either one circuit or thewhole unit to shut down. They are assigned code numbers aslisted in Table 79. Active pre-alerts/alerts/alarms are shown inCurrently Active Alarms, AlarmsoCRNT. Up to 20 currentalarms will be displayed. Pressing andbuttons simultaneously will expand the alarm code descriptiononly. Time and date stamps are available in Alarm History.If the unit is in alarm and unable to operate, Control Modewill show Run StatusoVIEWoSTAT=4 (Off Emrgcy). Au-tomatic alarms will reset without operator intervention if thecondition corrects itself. Manual alarms will require operatorintervention to reset the alarm.RESETTING ALARMS — Before resetting any alarm, firstdetermine the cause of the alarm and correct it. After determin-ing and correcting the cause of the alarm, toggleAlarmsoRCRN (Reset All Current Alarms) from NO toYES. The control may prompt the user for a password, by dis-playing PASS and WORD. See Configuration and ServicePassword on page 22 for information on the password. If thecondition has been resolved, the alerts/alarms will be clearedfrom the active alert/alarm set.ALARM HISTORY — The scrolling marquee and Naviga-tor™ display have the ability to display the latest alarms andalerts up to 20 events. This is a first-in, first-out alarm buffer.As a Pre-alert, Alert, or Alarm is generated, it is written to theAlarm History. To access Alarm History, enter AlarmsoHIST.Use the arrow keys to move through the history. The latest pre-alerts, alerts and alarms will appear first on the list. Pressingand simultaneously will provide a timeand date stamp and expand the pre-alert/alert/alarm code.Table 78 — TroubleshootingENTER ESCAPEENTER ESCAPESYMPTOM POSSIBLE CAUSES POSSIBLE REMEDIESUnit does not runCheck for power to unit Check overcurrent protection device.Check non-fused disconnect (if equipped).Restore power to unit.Check for 24 volts at the control boards.Wrong/incorrect unit configuration Check unit configuration.If unit is controlled by a Local Schedule, check tobe sure that the Day of the Week is properly set.Enable-Off-Remote Switch is not in a position toallow the unit to operate.Fan Status Switch is open.Active alarm Check alarm status. See Alarms and Alerts begin-ning on page 162 and follow troubleshootinginstructions.Active operating mode Check for Operating Modes. See the OperatingModes section beginning on page 135 and followtroubleshooting instructions.No cooling load Cooling Load is satisfied.Unit runs when it is not called for Incorrect unit configuration If unit is controlled by a Local Schedule, check tobe sure that the Day of the Week is properly set.Unit operates too long or continuouslyLow refrigerant charge Check for leak and add refrigerant.Compressor or control contacts welded Replace contactor or relay.Non-condensables in refrigerant circuit Remove refrigerant and recharge.Circuit does not runActive alarm Check alarm status. See Alarms and Alerts begin-ning on page 162 and follow troubleshootinginstructions.Active operating mode Check for Operating Modes. See the OperatingModes section beginning on page 135 and followtroubleshooting instructions.Circuit does not loadActive alarm Check alarm status. See Alarms and Alerts begin-ning on page 162 and follow troubleshootinginstructions.Active operating mode Check for Operating Modes. See the OperatingModes section beginning on page 135 and followtroubleshooting instructions.Low Saturated Suction Temperature See Alarms, Pre-Alerts, and Alerts A120, A121,P120,121, T120,121, page 168.Faulty compressor discharge check-valve Replace compressor.Compressor does not runActive alarm Check alarm status. See Alarms and Alerts begin-ning on page 162 and follow troubleshootinginstructions.Active operating mode Check for Operating Modes. See the OperatingModes section beginning on page 135 and followtroubleshooting instructions.Inoperative compressor contactor Check control wiring.Check contactor operation, replace if necessary.