Panasonic U-4..6ML5XPQ, Service Manual

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Troubleshooting by Indication on the Remote Controller
204 Troubleshooting
3.51
“
UF
”
System is not Set yet
Remote
Controller
Display
UF
Applicable
Models All models of indoor units
U-4..6ML5DPQ, U-4..6ML5XPQ
Method of
Malfunction
Detection On check operation, the number of indoor units in terms of transmission is not corresponding to
that of indoor units that have made changes in temperature.
Malfunction
Decision
Conditions The malfunction is determined as soon as the abnormality aforementioned is detected through
checking the system for any erroneous connection of units on the check operation.
Supposed
Causes
„
Improper connection of transmission wiring between indoor-outdoor units and outdoor-
outdoor units
„
Failure to execute check operation
„
Defect of indoor unit PC board
„
Stop valve is left in closed
Troubleshooting
Note: Wiring check operation may not be successful if carried out after the outdoor unit has been off
for more than 12 hours, or if it is not carried out after running all connected indoor units in the
fan mode for at least an hour.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
(V2830)
Is
indoor - outdoor
and outdoor - outdoor unit
transmission wiring
normal?
Replace indoor unit PC board.
Wiring check operation may
not have been carried out
successfully.
After fixing incorrect wiring,
push and hold the RESET
button on the master outdoor
unit PC board for 5 seconds.
∗
The unit will not run for up to
12 minutes.
YES
NO
YES
NO
NO
YES
Is the
check operation
carried out?
Is indoor
-outdoor and outdoor-
outdoor unit transmission
wiring normal?
Open stop valve.
YES
NO
Are the stop
valves openned?
Urban Multi ML5 · Mini UM · Heat Pump