Daikin VRV IV+ Service Manual page 252

3 | Components
3.7.2 Branch selector box expansion valve
Checking procedures
To perform a mechanical check of the expansion valve
To perform an electrical check of the expansion valve
Service manual
252
INFORMATION
It is recommended to perform the checks in the listed order.
Prerequisite: Power OFF the unit for 3 minutes. Then turn ON the unit and listen to
the expansion valve assembly. If the expansion valve does NOT make a latching
sound, continue with the electrical check of the expansion valve, see
4
procedures" [ 252].
Prerequisite: Stop the unit operation via the central controller.
Prerequisite: Turn OFF the respective circuit breaker.
Prerequisite: Remove the required plate work, see
1 Remove the expansion valve motor from the expansion valve body, see
"Repair procedures" [
2 Slide the expansion valve magnet over the expansion valve body and gently
rotate the magnet clockwise/counterclockwise to manually close/open the
expansion valve.
Does the expansion valve open?
Yes
No
Prerequisite: First perform a mechanical check of the expansion valve, see
"Checking procedures" [
1 Make sure that the valve coil is firmly slid onto the valve body.
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.
BS1Q-A
Expansion Symbol
valve name
Subcool Y1E
HP/LP gas pipe Y2E
Suction gas Y3E
pipe
4
257].
Action
Perform an electrical check of the
expansion valve, see
procedures" [
Replace the Branch selector box, see
Installation manual of the Branch
selector box.
4
252].
Connector
X4A
X7A
X8A
4
"3.15 Plate work" [ 315].
"Checking
4
252].
Winding BS1Q-A
resistance
46 ±3 Ω
150 ±15 Ω
150 ±15 Ω
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
"Checking
✔