Daikin altherma 3 M Service Manual page 150

3 | Components
To perform an electrical check of the expansion valve
Service manual
150
Does the expansion valve open?
No
1 First perform a mechanical check of the expansion valve, see
4
procedures" [ 149].
2 Disconnect the electrical connector of the expansion valve coil from the
appropriate PCB and measure the resistance of all windings (between the pins
of each phase (wire) and the common wire) using a multi meter. All
measurements MUST be approximately the same.
Name Symbol
Main Y1E
expansion
valve
Injection Y3E
expansion
valve
INFORMATION
Below is an example of the resistance measurements in which the common wire is
connected to pin 6 of the expansion valve coil connector. Connections may differ
according to the type of expansion valve.
▪ Connector pin 1‑6,
▪ Connector pin 2‑6,
▪ Connector pin 3‑6,
▪ Connector pin 4‑6.
a
a Connector
3 Check the insulation resistance of the coil by measuring the resistance
between the pins of each phase (1, 2, 3, 4) and GND on the unit.
Result: None of the measurements should be short‑circuit.
WARNING
When reconnecting a connector to the PCB, make sure to connect it on the correct
location and do NOT apply force, as this may damage the connector or connector
pins of the PCB.
Action
Replace the expansion valve body, see
"3.9.2 Repair procedures" [
Location (PCB) Connector
Main X21A
Main X22A
4
152].
"3.9.1 Checking
Winding
resistance
46±3 Ω
46±3 Ω
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
ESIE20-06A – 2021.03