Daikin VRV RXYQ72-384XAYCA Service Manual page 237

SiUS342004EB
3.3.2 External Protection Device Abnormality (FXTQ-TA, FXTQ-TB, CXTQ-TA
Only)
Applicable
FXTQ-TA, FXTQ-TB, CXTQ-TA
Models
A0-01
Error Code
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
 Activation of external protection device
Causes  Defective indoor unit PCB
 Indoor unit fuse blown
 24 VAC power is not supplied to TH2 and TR2 terminals (FXTQ-TA, FXTQ-TB) or R and C
Troubleshooting
Part 6 Service Diagnosis
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 external
YES
protection device is
opened.
NO
Fuse (F1U) is
blown.
NO
24 VAC
power is supplied to
TH2 and TR2 terminals
(FXTQ-TA, FXTQ-TB) or
R and C terminals
(CXTQ-TA).
NO
Troubleshooting by Error Code
YES
Activation 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.
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