Thermistors; Checking Procedures - Daikin Perfera RXM R Series Service Manual

3.19 Thermistors

3.19.1 Checking procedures

To perform a mechanical check of the specific thermistor
To perform an electrical check of the specific thermistor
RXM20~71R + ARXM25~71R + FTXM20~71R + ATXM25~50R +
FVXM25~50A
Split New Perfera R32
ESIE20-11 – 2021.01
INFORMATION
It is recommended to perform the checks in the listed order.
Prerequisite: Stop the unit operation via the user interface.
Prerequisite: Turn OFF the respective circuit breaker.
Prerequisite: Remove the required plate work, see
1 Locate the thermistor and remove the insulation if needed. Check that the
thermistor is correctly installed and that there is thermal contact between the
thermistor and the piping or ambient (for air thermistor).
Is the thermistor correctly installed
(thermal contact between the
thermistor and the piping)?
Yes
No
1 First perform a mechanical check of the thermistor, see
4
procedures" [ 189].
DANGER: RISK OF ELECTROCUTION
Wait for at least 10 minutes after the circuit breaker has been turned OFF, to be sure
the rectifier voltage is below 10 V DC before proceeding.
2 Locate the thermistor.
INFORMATION
Remove the thermistor from its holder if not reachable with a contact thermometer.
3 Measure the temperature using a contact thermometer.
Outdoor units
Name Symbol
Air R1T
thermistor
Heat R2T
exchanger
thermistor
"3.14 Plate
Action
Perform an electrical check of the
specific thermistor, see
procedures" [
Correctly install the thermistor, see
"Repair procedures" [
Location Connector
(PCB) (pins)
Main (O/U) S90:1‑2
Main (O/U) S90:3‑4
3 Components
|
4
work" [ 151].
"Checking
4
189].
4
193].
"Checking
Inter- Referen
mediate ce
connector (table)
(pins)
- A
- A
Service manual
189