Haier HSU09VHG(DB)-W Service Manual

Also see for 1U09ES2VHA: Installation manual

Contents

OUTDOOR UNIT CONTROLS & COMPONENTSPAGE 11ENGLISHDischarge Temperature SensorDefrost Temperature SensorThe Defrost Temperature Sensor is a negative coefficientthermistor that will change resistance in response to outdoorcoil temperature changes. The Main Control Board monitorsthe temperature of the outdoor coil to determine when thesystem is needing to perform a defrost cycle. The sensor alsomonitors outdoor coil temperature during defrost cycles todetermine termination conditions.This sensor connects to the Main Control Board at PLUG CN-19.The Discharge Temperature Sensor is a Negative Coefficientthermistor that senses the temperature of the compressorhot gas. The Main Control Board monitors the temperature ofthe compressor hot gas and will make inverter speed changesin response to input from this device.This sensor connects to the Main Control Board at PLUG CN-17.Outdoor Ambient Temperature SensorSuction Line Temperature SensorThe Suction Line Temperature Sensor is a negativecoefficient thermistor that senses the temperature ofthe suction line. The Main Control Board monitors thetemperature of the suction line to determine EEV orifice sizein an attempt to maintain proper operating superheat.This sensor connects to the Main Control Board at PLUG CN-18.The Outdoor Ambient Temperature Sensor is a negativecoefficient thermistor that will change resistance in responseto outdoor air temperature changes. The Main Control Boardmonitors the temperature of the outdoor air to determineoutdoor fan speed requirements and inverter speed. Thesensor also plays a role in calculation of required defrostconditions.This sensor connects to the Main Control Board at PLUG CN-20.