Carrier 38GRQB12-3 Service Manual

44TROUBLESHOOTING FOR NORMAL MALFUNCTION1. Air conditioner can not start upPossible Causes Discriminating Method (Air ConditionerStatus) TroubleshootingNo power supply or poor connection for powerplugAfter energizer, operation indicator is notbright and the buzzer can not give out sound.Confirm whether it's due to power failure. Ifyes, wait for power recovery. If not, checkpower supply circuit and make sure the powerplug is connected well.Wrong wire connection between indoor unitand the outdoor unit, or poor connection forwiring terminals.Under normal power supply circumstances,operation indicator is not bright afterenergizationCheck the circuit according to the circuitdiagram and connect wires correctly. Ensureall wiring terminals are connected firmly.Electric leakage from air conditioner After energization, room circuit breaker tripsoff at once.Ensure the air conditioner is ground reliably.Ensure wires of the air conditioner areconnected correctly. Check the wiring insidethe air conditioners. Check whether theinsulation layer of power cord is damaged; ifyes replace the power cord.Model selection for air switch is improper After energization air switch trips off Select proper air switchMalfunction of remote controllerAfter energization, operation indicator is brightwhile no display on remote controller orbuttons have no action.Replace batters for remote controller Repair orreplace remote controller2. Poor cooling (heating) for air conditionerPossible Causes Discriminating Method (Air ConditionerStatus) TroubleshootingSet temperature is improper Observe the set temperature on remotecontroller Adjust the set temperatureRotation speed of the IDU fan motor is set toolow Small wind blow Set the fan speed at high or mediumFilter of indoor unit is blocked Check the filter to see if its blocked Clean the filterInstallation position for the indoor and outdoorunits is improperCheck whether the installation position iscorrect according to installation requirementsfor air conditioner.Adjust the installation position and install therainproof and sun proof for the outdoor unitRefrigerant is leakingDischarged air temperature during cooling ishigher than normal discharged windtemperature. Discharged air temperatureduring heating is lower than normaldischarged wind temperature. Unit's pressureis much lower than regulated range.Find the leakage causes and repair them. Addrefrigerant.Malfunction of 4-way valve Blow cold wind during heating Replace the 4-way valveMalfunction of capillaryDischarged air temperature during cooling ishigher than normal discharged windtemperature. Discharged air temperatureduring heating is lower than normaldischarged wind temperature. Unit's pressureis much lower than regulated range. Ifrefrigerant is not leaking, part of capillary isblocked.Replace the capillaryFlow volume is insufficient The pressure of valves is much lower thanthat stated in the specification Open the valve completelyMalfunction of horizontal louver Horizontal louver can not swing Refer to point 3 of maintenance method fordetailsMalfunction of the IDU fan motor The IDU fan motor can not operate Refer to troubleshooting for H6 formaintenance method in detailsMalfunction of the ODU fan motor The ODU fan motor can not operate Refer to point 4 of maintenance method fordetailsMalfunction of compressor Compressor can not operate Refer to point 5 of maintenance method fordetails3. Horizontal louver can not swingPossible Causes Discriminating Method (Air ConditionerStatus) TroubleshootingWrong wire connection, or poor connection Check the wiring status according to thecircuit diagramConnect wires according to the wiring diagramto ensure all wiring terminals are connectedfirmlyStepping motor is damaged Stepping motor cannot operate Repair or replace stepping motorMain board is damaged Others are all normal while horizontal lovercan not operate Replace the main board with the same model