ESIE16-02B | Part 2. Troubleshooting 2.4. Component checklist
Page 56 4/04/17 | Version 1.1
RA R32 Split & multi split M-Series
2.4.2.8. Refrigerant thermistors
PRELIMINARY ACTIONS
1. Switch off the Daikin unit via the user interface.
2. Switch off the Daikin unit with the field supplied circuit breaker.
3. Locate the thermistor and check if thermal contact with the piping or ambient is ensured.
PRELIMINARY ACTIONS
1. Switch off the Daikin unit via the user interface.
2. Switch off the Daikin unit with the field supplied circuit breaker.
3. Remove plate work when required.
PROCEDURE
1. From the table in the appendix ("Component checklist" on page 111), select the thermistor that must be checked.
2. Measure the temperature of the thermistor using a contact thermometer.
3. Unplug the connector from the appropriate PCB and measure the resistance between the pins listed in the table in the
appendix ("Component checklist" on page 111).
- Compare the measured resistance with the range determined by the lower and higher temperature.
4. If the measured resistance does not match the listed value, the thermistor must be replaced.
E.g. R3T air thermistor - main PCB - connector S90: pin 1-2 type 1:
• Measured temperature with contact thermometer: 23.1°C.
• Unplug the sensor and measure the resistance between S90: 1-2: 21.86 kΩ.
Technical specification Description
A single type of thermistor is used; the resistance vs. tempera-
ture characteristics is shown in below table "Thermistor resist-
ance / temperature characteristics (type 1)".
The thermistors are used to measure the temperature at multiple
locations inside the Daikin unit. The measured temperatures are
processed by the main board.
Location
Piping diagram Wiring diagram Switch box Component overview of unit
See "Outdoor unit" on
page 104.
See "Outdoor unit" on
page 99.
See "Outdoor unit" on
page 111.
See "Outdoor unit" on page 110.
Check procedure
Mechanical check
Electrical check
INFORMATION
If a thermistor check fails, replace the thermistor.
WARNING: RISK OF FIRE
When reconnecting a connector to the PCB, do not apply force, as this may damage the connector or connector pins of
the PCB.
INFORMATION
All thermistors have a tolerance of 5%.