SiBE12-818 Control SpecificationFunction and Control 833.10 Defrost ControlOutline Heat Pump OnlyDefrosting is carried out by the cooling cycle (reverse cycle). The defrosting time or outdoorheat exchanger temperature must be more than its fixed value when finishing.Detail Conditions for Starting DefrostThe starting conditions must be made with the outdoor air temperature and heat exchangertemperature. Under the conditions that the system is in heating operation, 6 minutes after thecompressor is started and more than 38 minutes of accumulated time pass since the start of theoperation or ending the defrosting.Conditions for Canceling DefrostThe target heat exchanger temperature as the canceling condition is selected in the range of4°CThe target heat exchanger temperature=–(45/65)×(ambient temperature)+14The defrost operation surely operates in 120 seconds after the start. (A→B)After then the defrost operation stops at the following conditions.1. When the heat exchanger temperature reaches the target heat exchanger temperature.(B→C)2. When 650 seconds have passed after the start even if the heat exchanger temperature doesnot reaches the target heat exchanger temperature. (C)A B C450pls 350pls160pls400pls0pls(R7124)
