Panasonic U-72MF2U9 Service Manual

Also see for U-120MF2U9: Installation instructions Operating instructions Installation instructions Technical data

Contents

5 - 141234567893WAY VRF SYSTEMTrouble Diagnosis3. 3WAY Alarm CodesF17 AlarmAlarm code F17Alarm meaning Low pressure sensor of the outdoor unit has failure. (LPS)Alarm conditions (1) Sensor short circuit(2) Sensor open circuitProbable cause (1) Sensor malfunction (including connector)(2) The Outdoor Unit Control PCB malfunctionCheck (1) Measure the sensor resistance. Check that the sensor is operating normally.Use a remote monitor or a PC monitor to check the temperature that is recognizedby the microcomputer.(2)Correction ——————ExampleNotesF31 AlarmAlarm code F31Alarm meaning EEPROM on outdoor unit PCB has failure.Alarm conditions (1) Non-volatile memory is not present when power initialization occurs.(2) Read values do not match after writing to non-volatile memory is complete.Probable cause (1) Memory was not inserted after the Outdoor Unit Control PCB was replaced.(2) The lifetime of the non-volatile memory has been reached.(3) Non-volatile memory is installed incorrectly (wrong direction, bent pins, etc.).Check (1) Check the non-volatile memory on the Outdoor Unit Control PCB.CorrectionExampleNotes2WAY SYSTEMTrouble Diagnosis4. 2WAY Alarm Codes(1) Wiring failure(2) Operating under extremely high-pressure status (over-loaded operation)(3) Power source and voltage failure (sudden voltage decrease)(2) Operating under extremely high-pressure status (over-loaded operation)Check open/closed status of the service valve of the outdoor unit.(3) Check power source and voltage.H01, H11 AlarmAlarm codeAlarm meaningAlarm conditionsProbable causeCheckCorrectionExampleNotesH01, H11H01 : Overcurrent in 1st compressor.H11 : Overcurrent in 2nd compressor.1st compressor, 2nd compressor primary current detected overcurrent higher than the values(overcurrent) listed in the table below.(1) Wiring failure(2) Operating under extremely high-pressure status (over-loaded operation)(3) Improving power source and voltage(1) Wiring failure——Type of outdoor unitCurrent (A)7230.09643.012030.014430.0Failure to open the service valve of the outdoor unit•Check whether the connection between “HIC PCB” and “inverter compressor” is wiring failure.Open the service valve of the outdoor unit.•Correct wiring disconnection and wiring failure.Replacing high-pressure sensorWhen replacing a high-pressure sensor, carry out after refrigerant recovering of the outdoor unit.•Connect a gauge to the high-pressure outlet and check for changes in the value displayedby the monitoring software, and for large deviation of the gauge pressure.•