If A Sensor Is Defective - Sanyo SAP–K91AHA Technical & Service Manual

9-5. If a sensor is defective.

9-5-1. Indoor coil temp. thermistor (TH1) is defective.
• Operation lamp on front side of
indoor unit is flashing on and off. (*)
NOTE
Alarm Signal (*)
Operation lamp on the front side of the indoor unit will flash on and off when the indoor coil thermistor is defective.
At the same time the outdoor unit will stop. Indoor unit will operate only for ventilation.
9-5-2. Room temp. thermistor (TH2) is defective.
A. Open
When thermistor opens, the air conditioner will be in the following conditions as the controller tries to detect
extremely low room temperature.
a) In Cooling mode: The air conditioner soon stops and will not start again. (Thermo.OFF) Neither outdoor fan
b) In Heating mode: The air conditioner continues to operate (Thermo.ON). Both the outdoor fan and
B. Short
When thermistor is short, the air conditioner will be in the following conditions as the controller tries to detect
extremely high room temperature.
a) In Cooling mode: The air conditioner continues to operate (Thermo.ON). Both the outdoor fan and
b) In Heating mode: The air conditioner soon stops and will not start again (Thermo.OFF). Neither outdoor fan
NOTE
Definition of Open or Short Circuit of Sensor (Thermistor)
Open ... A lead wire is broken or disconnected or the circuit inside the temperature sensor is open .
Short ... The protective cover of a lead wire has been damaged, and the exposed wire is touching another metal
part, or both lead wires have become exposed and are touching each other. Alternatively, the circuit
inside the temperature sensor is closed.
YES
nor compressor runs.
compressor do not stop. As a result, the room becomes too warm.
compressor do not stop. As a result, the room becomes too cold.
nor compressor runs.
• Thermistor (TH1 ) is defective.
(That is, sensor is SHORT.)
• Replace thermistor.
46
YES