Daikin RXSQ24TAVJU Service Manual page 174

Troubleshooting by Error Code
4.4.1 External Protection Device Abnormality (FXTQ-TA and CXTQ-TA Only)
A0-01
Error Code
Applicable
FXTQ-TA, CXTQ-TA
Models
Method of Error Detect open or short circuit between external input terminals in indoor unit.
Detection
Error Decision
When an open circuit occurs between external input terminals.
Conditions
Supposed
Causes
Troubleshooting
161
Actuation of external protection device
Defective indoor unit PCB
Indoor unit fuse blown
24 VAC power is not supplied to TH2 and TR2 terminals (FXTQ-TA) or R and C terminals
(CXTQ-TA) on the indoor unit PCB.
Be sure to turn off the power switch before connecting or disconnecting
Caution connectors, or parts may be damaged.
External
protection device
is connected to TB4 and
TB5 of the indoor unit
terminal.
NO
The
YES
external protection
device is opened.
NO
Fuse (F1U)
is blown.
NO
24 VAC
power is supplied
to TH2 and TR2
terminals (FXTQ-TA) or R
and C terminals
(CXTQ-TA).
NO
SiUS331708EA
YES
Actuation of external protection
device.
YES
Replace the fuse (F1U).
YES
Replace the indoor unit PCB.
Confirm that wiring follows
the wiring diagram and then
supply power to each
terminal.
Service Diagnosis