Checking The Thermistors - Daikin Sky Air R-407C Service Manual

Additional Checks for Troubleshooting
5.8

Checking the Thermistors

1
Thermistors
Overview of
thermistors
3 3
4
Checking
5
3–72
If the cause of the problem is related to the thermistors, then the thermistors should be checked prior
to changing the PCB.
For more information about these thermistors, see:
'Wiring Diagrams: Outdoor Units'
'Wiring Diagrams: Indoor Units'
"Functions of Thermistors: Large Heat Pumps" on page 5.
The table below contains an overview of the thermistors:
Thermistor
Indoor R1T
R2T
Outdoor R1T
R2T
R3T
To check the thermistors, proceed as follows:
Step Action
1 Disconnect the thermistor from the PCB.
2 Read the temperature and the resistor value.
3 Check if the measured values correspond with the values in the table on the next pages.
Description
Suction air thermistor
Heat exchanger thermistor (coil thermistor)
Ambient air thermistor
Heat exchanger thermistor (coil thermistor)
Discharge pipe thermistor
ESIE02–01
Part 3 – Troubleshooting