Transmission Error Between Indoor Units And Outdoor Units In The Same System - Daikin VRV EMERION REYQ-AATJA Service Manual

SiUS372201EB
3.72 Transmission Error between Indoor Units and Outdoor
Units in the Same System
Applicable
All indoor unit models
Models
All outdoor unit models
U9
Error Code
Method of Error
Detect the error signal for the other indoor unit within the circuit by outdoor unit main PCB.
Detection
Error Decision
When the error decision is made on any other indoor unit within the system concerned
Conditions
Supposed
 Transmission error between other indoor and outdoor units
Causes  Defective electronic expansion valve of other indoor unit
 Defective indoor unit control PCB of other indoor unit
 Improper connection of transmission wiring between indoor and outdoor unit
 Multi-tenant function is ON.
Troubleshooting
Part 6 Service Diagnosis
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
Turn ON all indoor units.
NO
All the units
display U9.
YES
U9 has
NO
been displayed for 2
minutes or more.
YES
Troubleshooting by Error Code
Continue the operation.
Re-diagnose by display after
passage of 2 minutes or more.
The outdoor unit main PCB
indicated by the error code U9 is
normal.
Check for the indoor unit of other
system, and then conduct
troubleshooting by diagnosis
according to the Error Code
Flowchart.
430