Service Manual

SiUS281811E
72 Part 4 Functions and Control
1. Operation Mode ........................................................................................73
2. Basic Control.............................................................................................74
2.1 Normal Operation ....................................................................................... 74
2.2 Compressor PI Control............................................................................... 75
2.3 Electronic Expansion Valve PI Control....................................................... 77
2.4 Cooling Operation Fan Control................................................................... 78
3. Special Control..........................................................................................79
3.1 Startup Control ........................................................................................... 79
3.2 Oil Return Control....................................................................................... 81
3.3 Defrost Control ........................................................................................... 83
3.4 Pump Down Residual Control .................................................................... 84
3.5 Restart Standby.......................................................................................... 85
3.6 Stop Control ............................................................................................... 85
4. Protection Control .....................................................................................86
4.1 High Pressure Protection Control............................................................... 86
4.2 Low Pressure Protection Control................................................................ 87
4.3 Discharge Pipe Temperature Protection Control........................................ 89
4.4 Inverter Protection Control ......................................................................... 90
5. Other Control.............................................................................................92
5.1 Demand Operation ..................................................................................... 92
5.2 Heating Operation Prohibition .................................................................... 92
6. Outline of Control (Indoor Unit) .................................................................93
6.1 Remote Controller Thermistor .................................................................... 93
6.2 Thermostat Control..................................................................................... 95
6.3 Thermostat Control with Operation Mode Set to AUTO ............................. 97
6.4 List of Swing Flap Operations .................................................................... 98
6.5 Hot Start Control (In Heating Operation Only)............................................ 99
6.6 Louver Control for Preventing Ceiling Dirt (FCQ Models Only)................ 100
6.7 Drain Pump Control.................................................................................. 101
6.8 Freeze-Up Prevention .............................................................................. 103
6.9 Heater Control (Except FTQ-TA Models) ................................................. 105
6.10 Heater Control (FTQ-TA Models) ............................................................. 106
6.11 3-Step Thermostat Processing (FTQ-TA Models).................................... 110
6.12 Fan Control (Heater Residual) (FTQ-TA Models) .................................... 111
6.13 Interlocked with External Equipment (FTQ-TA Models) ........................... 111
Part 4
Functions and Control