Discharge Temperature Sensor; Defrost Temperature Sensor; Outdoor Ambient Temperature Sensor; Suction Line Temperature Sensor - Haier AW09ES2VHB Service Manual

Discharge Temperature Sensor

The Discharge Temperature Sensor is a Negative Coefficient
thermistor that senses the temperature of the compressor
hot gas. The Main Control Board monitors the temperature of
the compressor hot gas and will make inverter speed changes
in response to input from this device.
This sensor connects to the Main Control Board at PLUG
CN-17.

Defrost Temperature Sensor

The Defrost Temperature Sensor is a negative coefficient
thermistor that will change resistance in response to outdoor
coil temperature changes. The Main Control Board monitors
the temperature of the outdoor coil to determine when the
system is needing to perform a defrost cycle. The sensor also
monitors outdoor coil temperature during defrost cycles to
determine termination conditions.
This sensor connects to the Main Control Board at PLUG
CN-19.
OUTDOOR UNIT CONTROLS & COMPONENTS

Outdoor Ambient Temperature Sensor

The Outdoor Ambient Temperature Sensor is a negative
coefficient thermistor that will change resistance in response
to outdoor air temperature changes. The Main Control Board
monitors the temperature of the outdoor air to determine
outdoor fan speed requirements and inverter speed. The
sensor also plays a role in calculation of required defrost
conditions.
This sensor connects to the Main Control Board at PLUG
CN-20.

Suction Line Temperature Sensor

The Suction Line Temperature Sensor is a negative
coefficient thermistor that senses the temperature of
the suction line. The Main Control Board monitors the
temperature of the suction line to determine EEV orifice size
in an attempt to maintain proper operating superheat.
This sensor connects to the Main Control Board at PLUG
CN-18.
PAGE 11