Carrier 39L Series Installation, Operation, And Start-up Instructions

Also see for 39L Series: Installation, Start-Up and Service Instructions

Carrier 39L Series Installation, Operation, And Start-up Instructions Manual pdf 113 page image

UNIT TROUBLESHOOTINGPROBLEM POSSIBLE CAUSE CORRECTIVE ACTIONUnit does not runPIC control is OFF Check for correct power or blown fuses (F2).Correct any deficiencies.Faulty connectionsCheck LEDs on control module (PSIO). If LED is not solidlyilluminated, check for loose connections. If all wires andconnectors are secure, replace PSIO module as describedon page 112.PIC control has incorrect time Verify control shows correct time. If incorrect, enter correcttime.Supply fan HOA switch in OFF positionSafety controls are trippedVerify HOA switch is in the AUTO position.Check low-temperature thermostat and high-pressure switch(VAV units only). Reset switches if necessary.PIC control left in Quick Test(Display shows Mode 38)Using the local interface device, exit Quick Test.Press 5 TEST, and then ENTR to exit.Unit is configured for and is currentlyin Demand Limit Mode (CV units only)Verify that unit should be in the Demand Limit mode. If not,cycle power to PIC to release unit from Demand Limitmode.Unit is in Smoke Evacuation or Fire Shut-down mode (Display shows 35 or 37) Verify that unit should be in one of these modes. If not,check for shorted input on Fire Shutdown or Evacuation.Minimum inverter set point too low(VAV units only)Adjust minimum to 20% at 4 mA signal and 100% at 20 mAsignal.No heatNo fan status Check status of SFS (4 STAT). If SFS is OFF, check supplyfan status switch for proper operation. Switch must be ONfor heat coil to function properly.Heat coil valve (HCV) is forced closed Check status of HCV (5 STAT). If HCV is forced, removeforce and check operation.NO hot water or steam available,no power if electric heat Check source and correct any problems found.Electric heater safety tripped Reset heater safety. Check for proper operation.No power to valveCheck for blown fuse (F6). Replace if necessary. If fuseis intact, check for proper connections. Check transformeroutput.No power to electric heater controlCheck for blown fuse (F5). Replace if necessary. If fuseis intact, check for proper connections. Check transformeroutput.Incorrect reading from space temperature sensor,supply-air temperature sensor, or return-airtemperature sensor (VAV units)Check status of sensor readings for accuracy.Replace sensor if defective.Configuration errorCheck configuration for proper heating set point andSubmaster Gain (SMG). An improper SMG can cause theheating valve to be held closed.OverheatingHeat coil valve (HCV) is forced open Check status of HCV (5 STAT). If HCV is forced, removeforce and check operation.Incorrect reading from space temperature sensor,supply-air temperature sensor, or return-airtemperature sensor (VAV units)Check status of sensor readings for accuracy. Replacesensor if defective.Configuration errorCheck configuration for proper heating set point andSubmaster Gain (SMG). An improper SMG can cause theheating valve to be held open.No coolingNo fan statusCheck status of SFS (4 STAT). If status is OFF, checkswitch for proper operation. Supply fan status switch mustbe ON for cooling coil to function properly.Cooling coil valve (CCV) is forced closed Check status of CCV (5 STAT). If CCV is forced, removeforce and check operation.No chilled water available Check source of chilled water. Correct any problems found.No power to cooling coil valveCheck for blown fuse (F3). Replace if necessary. If fuseis intact, check for proper connections. Check transformeroutput.Incorrect reading from space temperature sensor,supply-air temperature sensor, or return-airtemperature sensor (VAV units)Check status of sensor readings for accuracy. Replacesensor if defective.Configuration errorCheck configuration for proper cooling set point andSubmaster Gain (SMG). An improper SMG can cause theCCV to be held closed.OvercoolingCooling coil valve (CCV) is forced open Check status of CCV (5 STAT). If CCV is forced, removeforce and check operation.Incorrect reading from space temperature sensor,supply-air temperature sensor, or return-airtemperature sensor (VAV units)Check status of sensor readings for accuracy. Replacesensor if defective.Configuration error Check configuration for proper cooling set point andSubmaster Gain (SMG). An improper SMG can cause theCCV to be held open.LEGENDCV — Constant VolumeVAV — Variable Air Volume113

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