Symptom-Based Troubleshooting - Daikin RXYQ96PYDN Service Manual

Symptom-based Troubleshooting

1. Symptom-based Troubleshooting
Symptom
1 System does not start operation at all.
2 System starts operation but makes an immediate
stop.
3 System does not cool or heat air well.
4 System does not The system stops and
operate. immediately restarts
operation.
Pressing the TEMP ADJUST
button immediately resets the
system.
The remote controller displays
UNDER CENTRALIZED
CONTROL, which blinks for a
period of several seconds
when the OPERATION button
is depressed.
The system stops immediately
after turning ON the power
supply.
5 System makes The remote controller displays
intermittent malfunction codes [U4] and
stops. [U5], and the system stops but
restarts after a lapse of
several minutes.
318
Probable Cause
Blowout of fuse(s)
Cutout of breaker(s)
Power failure
Blocked air inlet or outlet of indoor
or outdoor unit
Clogged air filter(s)
Blocked air inlet or outlet of indoor
or outdoor unit
Clogged air filter(s)
Enclosed outdoor unit(s)
Improper set temperature
Airflow rate set to LOW
Improper direction of air diffusion
Open window(s) or door(s)
[In cooling] Direct sunlight received
[In cooling] Too many persons staying in a
room
[In cooling] Too many heat sources (e.g. OA
equipment) located in a room
If the OPERATION lamp on the
remote controller turns ON, the
system will be normal. These
symptoms indicate that the system
is controlled so as not to put
unreasonable loads on the system.
The system is controlled with
centralized controller. Blinking
display indicates that the system
cannot be operated using the
remote controller.
The system is in preparation mode
of micro computer operation.
The system stops due to an
interruption in communication
between units caused by electrical
noises coming from equipment
other than air conditioners.
SiUS34-801A_b
Countermeasure
Turn Off the power supply and then
replace the fuse(s).
• If the knob of any breaker is in its
OFF position, turn ON the power
supply.
• If the knob of any circuit breaker
is in its tripped position, do not
turn ON the power supply.
ON
Knob
Tripped
OFF
Circuit breaker
After the power failure is reset,
restart the system.
Remove obstacle(s).
Clean the air filter(s).
Remove obstacle(s).
Clean the air filter(s).
Remove the enclosure.
Set the temperature to a proper
degree.
Set it to a proper airflow rate.
Set it to a proper direction.
Shut it tightly.
Hang curtains or shades on
windows.
Normal operation. The system will
automatically start operation after a
lapse of five minutes.
Operate the system using the
COOL/HEAT centralized remote
controller.
Wait for a period of approximately
one minute.
Remove causes of electrical noises.
If these causes are removed, the
system will automatically restart
operation.
Troubleshooting