Si12-308 Control SpecificationFunction and Control 933.2 Frequency ControlOutline Frequency that corresponds to each room’s capacity will be determined according to thedifference in the temperature of each room and the temperature that is set by the remotecontroller.The function is explained as follows.1. How to determine frequency.2. Frequency command from an indoor unit. (The difference between a room temperature andthe temperature set by the remote controller.)3. Frequency command from an indoor unit. (The ranked capacity of the operating room).4. Frequency initial setting.5. PI control.Detail How to Determine FrequencyThe compressor’s frequency will finally be determined by taking the following steps.For Heat Pump Model1. Determine command frequency Command frequency will be determined in the following order of priority.1.1 Limiting frequency by drooping function Input current, discharge pipes, low Hz high pressure limit, peak cutting, freeze-up protection,dew prevention, fin thermistor temperature.1.2 Limiting defrost control time1.3 Forced cooling / heating1.4 Indoor frequency command2. Determine upper limit frequency Set a minimum value as an upper limit frequency among the frequency upper limits of thefollowing functions:Compressor protection, input current, discharge pipes, Low Hz high pressure, peak cutting,freeze-up protection, defrost.3. Determine lower limit frequency Set a maximum value as an lower limit frequency among the frequency lower limits of thefollowing functions:Four way valve operating compensation, draft prevention, pressure difference upkeep.4. Determine prohibited frequency There is a certain prohibited frequency such as a power supply frequency.For Cooling Only Model1. Determine command frequency Command frequency will be determined in the following order of priority.1.1 Limiting frequency by drooping functionInput current, discharge pipes, freeze-up protection, dew prevention, fin thermistor temperature.1.2 Indoor frequency commandCommand frequency Limit frequency Skip controlEach upper limit functionCompressor protection functionEach lower limit functionFour-way valve operating compensation, etc. (*)Initial frequencyPI controlDefrost control (*)Each drooping functionInput current control, etc.Upper limit frequencyFMAXLower limit frequencyFMINTarget frequencyCommand frequency X repeats when frequency becomes lowerFrequency changes by PI control < repeats when frequency becomes lower*; only for heat pump model(R1375)
