SiUS30-604Function 53Part 4Function1. Function General.......................................................................................551.1 Symbol ....................................................................................................... 551.2 Operation Mode.......................................................................................... 561.3 Normal Operation ....................................................................................... 571.4 BS unit & Indoor unit operation mode detail............................................... 582. Stop...........................................................................................................592.1 Stopping Operation .................................................................................... 593. Standby .....................................................................................................613.1 Restart Standby.......................................................................................... 613.2 Crankcase Heater Control.......................................................................... 614. Startup Control ..........................................................................................624.1 Cooling Start-up Control............................................................................. 624.2 Heating Start-up Control............................................................................. 634.3 Pressure Equalizing Control....................................................................... 645. Normal Control ..........................................................................................655.1 Compressor Control ................................................................................... 655.2 Electronic Expansion Valve Control ........................................................... 675.3 Heat Exchange Mode in Heating Operation orSimultaneous Cooling / Heating Operation ................................................ 686. Protection Control .....................................................................................706.1 High Pressure Protection Control............................................................... 706.2 Low Pressure Protection Control................................................................ 716.3 Discharge Pipe Protection Control ............................................................. 736.4 Inverter Protection Control ......................................................................... 746.5 Cooling Fan Control ................................................................................... 757. Special Operation......................................................................................767.1 Oil Return Operation .................................................................................. 767.2 Oil Return Operation of Water Heat Exchanger ......................................... 787.3 Pump-down Residual Operation Control.................................................... 797.4 Refrigerant Drift Prevention........................................................................ 818. Other Control.............................................................................................828.1 Outside Unit Rotation ................................................................................. 829. Outline of Control (Indoor Unit) .................................................................839.1 Drain Pump Control.................................................................................... 839.2 Louver Control for Preventing Ceiling Dirt.................................................. 859.3 Thermostat Sensor in Remote Controller................................................... 869.4 Thermostat Control While in Normal Operation ......................................... 889.5 Thermostat Control in Dry Operation ......................................................... 889.6 Electronic expansion Valve Control............................................................ 899.7 Hot Start Control (In Heating Operation Only)............................................ 89