Mitsubishi Electric PUHY-HP200YNW-A Service Handbook page 186

Chapter 8 Troubleshooting Based on Observed Symptoms
8-1 MA Remote Controller Problems......................................................................................................... 1
8-1-1 The LCD Does Not Light Up. .................................................................................................................. 1
8-1-2 The LCD Momentarily Lights Up and Then Goes Off. ............................................................................ 2
8-1-3 "HO" and "PLEASE WAIT" Do Not Go Off the Screen. .......................................................................... 3
8-1-4 Air Conditioning Units Do Not Operate When the ON Button Is Pressed. .............................................. 4
8-2 ME remote Controller Problems .......................................................................................................... 5
8-2-1 The LCD Does Not Light Up. .................................................................................................................. 5
8-2-2 The LCD Momentarily Lights Up and Then Goes Off. ............................................................................ 6
8-2-3 "HO" or "Waiting for ···" Does Not Go Off the Screen............................................................................. 7
8-2-4 "88", "Request denied." Appears on the LCD. ........................................................................................ 9
8-3 Refrigerant Control Problems............................................................................................................ 10
8-3-1 Units in the Cooling Mode Do Not Operate at Expected Capacity........................................................ 10
8-3-2 Units in the Heating Mode Do Not Operate at Expected Capacity. ...................................................... 12
8-3-3 Outdoor Units Stop at Irregular Times. ................................................................................................. 14
8-4 Checking Transmission Waveform and for Electrical Noise Interference .................................... 15
8-4-1 M-NET................................................................................................................................................... 15
8-4-2 MA Remote Controller .......................................................................................................................... 17
8-5 Pressure Sensor Circuit Configuration and Troubleshooting Pressure Sensor Problems......... 18
8-5-1 Comparing the High-Pressure Sensor Measurement and Gauge Pressure......................................... 18
8-5-2 High-Pressure Sensor Configuration (63HS1)...................................................................................... 19
8-5-3 Comparing the Low-Pressure Sensor Measurement and Gauge Pressure.......................................... 20
8-5-4 Low-Pressure Sensor Configuration (63LS) ......................................................................................... 21
8-6 Troubleshooting Solenoid Valve Problems...................................................................................... 22
8-7 Troubleshooting Outdoor Unit Fan Problems.................................................................................. 24
8-8 Troubleshooting LEV Problems ........................................................................................................ 25
8-8-1 General Overview on LEV Operation.................................................................................................... 25
8-8-2 Possible Problems and Solutions ......................................................................................................... 28
8-8-3 Coil Removal Instructions ..................................................................................................................... 29
8-9 Troubleshooting Inverter Problems .................................................................................................. 31
8-9-1 Inverter-Related Problems and Solutions ............................................................................................. 31
8-9-2 Checking the Inverter Board Error Detection Circuit............................................................................. 33
8-9-3 Checking the Compressor for Ground Fault and Coil Resistance Problems ........................................ 33
8-9-4 Checking the Inverter for Damage at No-Load ..................................................................................... 34
8-9-5 Checking the Inverter for Damage during Compressor Operation........................................................ 35
8-9-6 Checking the Fan Motor for Ground Fault and Coil Resistance Problems ........................................... 36
8-9-7 Checking the Fan Board Error Detection Circuit at No Load ................................................................ 36
8-9-8 Checking the Fan Board for Damage at No Load................................................................................. 37
8-9-9 Checking the Fan Board for Damage with Load ................................................................................... 38
8-9-10 Checking the Installation Conditions..................................................................................................... 39
8-9-11 Solutions for the Main Breaker Trip ...................................................................................................... 39
8-9-12 Solutions for the Main Earth Leakage Breaker Trip .............................................................................. 40
8-9-13 Simple Check on Inverter Circuit Components ..................................................................................... 41
8-9-14 Troubleshooting Problems with IGBT Module ...................................................................................... 42
8-9-15 Checking the Fan Inverter Heatsink for Clogging ................................................................................. 44
8-10 Control Circuit..................................................................................................................................... 45
8-10-1 Control Power Supply Function Block................................................................................................... 45
8-10-2 Troubleshooting Problems with Outdoor Unit Transmission Power Supply Circuit .............................. 46
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