Prognostic & Diagnostic Sensors - Lennox LGT092H Installation Instructions Manual

Diagnostic Sensors
Units are equipped with four factory-installed thermistors
(RT46 - RT49) located on different points on the
refrigerant circuit.
The thermistors provide the Unit Controller with constant
temperature readings of four specific locations on the
THERMISTOR LOCATION - EVAPORATOR COIL
RT46, RT47
FIGURE 23
Page 24
refrigeration circuit. These temperatures are used as
feedback in certain modes of unit operation. In addition,
the Unit Controller uses these temperatures to initiate
alarms such as loss of condenser or evaporator airflow
and loss of charge.
Each thermistor must be specifically placed for proper
unit operation and to initiate valid alarms. See figure 23
and figure 24 proper locations.
22J06
BLUE
RT47
22J06
YELLOW
RT46