MXS Service Manual

SiUS121736EA Troubleshooting for SA Indoor Unit
Service Diagnosis 178
6.12 Mismatching of Indoor Unit and Outdoor Unit
Error Code UA
Error Decision
Conditions
 Improper combination of indoor and outdoor units
Supposed
Causes
 Defective indoor unit PCB
 Indoor-outdoor unit transmission wiring error
 Defective optional unit(s) wirings
 Improper power supply wiring of indoor unit
 Improper wiring of connecting wires between indoor/outdoor units
Troubleshooting
Connect the wirings correctly.
Replace the indoor unit PCB
(control PCB).
Normal
Connect the wirings correctly.
Check the power supply system
inside the indoor unit.
Could be incorrect wiring.
Check again.
YES
YES
NO
NO
Connect the indoor/outdoor
units correctly.
YES
YES
YES
YES
NO
NO
NO
Blink
(R24591)
Is the combination
of indoor/outdoor
units correct?
Do the service
monitors of all the
indoor units blink?
Are the wirings
between indoor unit and
outdoor unit correctly
connected?
Connect the wirings correctly.
NO
Is the optional
units power supply
connected from the
indoor unit terminal
block No.1 and
No.2?
Does the system conduct
normal operation?
Are the wirings
between indoor unit and
outdoor unit correctly
connected?
Turn off the power supply.
Then, turn on the power
supply to restart the system.
Continuously
ON or OFF
Is the voltage
between No.1 and
No.2 on the indoor
unit terminal block
208 - 230
VAC?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.