Control Specification SiUS04111134 Function and Control3.2 Frequency ControlOutline Frequency is determined according to the difference between the room thermistor temperature andthe target temperature.The function is explained as follows.1. How to determine frequency2. Frequency command from the indoor unit (Difference between the room thermistor temperatureand the target temperature)3. Frequency initial setting4. PI controlDetail How to Determine FrequencyThe compressor’s frequency is determined by taking the following steps.For Cooling Only Model1. Determine command frequency Command frequency is determined in the following order of priority.1. Forced cooling2. Indoor frequency command2. Determine upper limit frequency The minimum value is set as an upper limit frequency among the frequency upper limits of thefollowing functions:Compressor protection, input current, discharge pipe temperature, freeze-up protection.3. Determine lower limit frequency The maximum value is set as an lower limit frequency among the frequency lower limits of thefollowing function:Pressure difference upkeep.4. Determine prohibited frequency There is a certain prohibited frequency such as a power supply frequency.For Heat Pump Model1. Determine command frequency Command frequency is determined in the following order of priority.1. Limiting defrost control time2. Forced cooling3. Indoor frequency commandCommand frequency Limit frequency Skip controlLower limit functionFour way valve operating compensation (∗), etc.Initial frequencyPI controlDefrost control (∗)Dropping functionInput current control, etc.Upper limit functionCompressor protection functionUpper limit frequencyFMAXLower limit frequencyFMINTarget frequency(R14717)When the shift of the frequency is less than zero (ΔF<0) by PI control,the target frequency is used as the command frequency.(∗): only for heat pump model
