Daikin VRV IV+ Service Manual page 348

3 | Components
3.21 Thermistors
3.21.1 Refrigerant side thermistors
Checking procedures
To perform a mechanical check of the specific thermistor
To perform an electrical check of the specific thermistor
Service manual
348
INFORMATION
It is recommended to perform the checks in the listed order.
Prerequisite: Stop the unit operation via the central controller.
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" [ 348].
DANGER: RISK OF ELECTROCUTION
Confirm the rectifier voltage is below 10 V DC before proceeding, see
rectifier voltage" [
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.
Name Symbol
Air thermistor R1T
Main Liquid R3T
Pipe
thermistor
Action
Perform an electrical check of the
specific thermistor, see
procedures" [
Correctly install the thermistor, see
"Repair
4
356].
Location (PCB) Connector
Main
Main
4
"3.15 Plate work" [ 315].
"Checking
4
348].
4
procedures" [ 352].
"To check the
Type
(pins)
X18A:1‑3 1
X30A:1‑2 1
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
"Checking