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

SiUS371901E
3.69 Transmission Error between Indoor Units and Outdoor
Units in the Same System
U9
Error Code
Applicable All indoor unit models
All outdoor unit models
Models
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
Causes
Troubleshooting
Service Diagnosis
Transmission error between other indoor and outdoor units
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.
Be sure to turn off the power switch before connecting or disconnecting
Caution
connectors, or parts may be damaged.
Turn ON all indoor units.
All the units
display U9.
YES
U9 has
been displayed for 2
minutes or more.
YES
NO
NO
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.
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