Daikin E Series, Service Manual

Page: 368 / 453

SiAU18-715 Troubleshooting for BP Unit
Troubleshooting 355
6.5 Transmission Error between Outdoor Unit and BP Unit
Outdoor Unit
Indication
UJ
Method of
Malfunction
Detection Transmission error is detected when the outdoor unit could not received the data from BP unit
correctly.
Malfunction
Decision
Conditions When the data from BP unit could not be correctly received continuously for 10 minutes
Supposed
Causes
„
Incorrect connection of transmission wire
„
Faulty outdoor unit power supply
„
Faulty BP unit PCB
„
Faulty outdoor unit PCB
„
Distortion of power supply wave
Troubleshooting
Check No.14
Refer to P.356
YES
Check the transmission
wire and the connection
orders.
Replace outdoor unit
control PCB.
Could be outside causes
other than errors.
Probe where the noise
comes from, and apply
remedy required.
Probe the causes for
deformation of power
supply waveform and apply
remedy required.
Replace outdoor unit
control PCB.
NO
Turn the power supply off.
Is it normal?
Check the transmission wire
between outdoor unit - BP
unit
Is HAP on
the outdoor unit PCB
blinking?
NO
Turn the power supply back
on.
YES
NO
(Q0549)
YES
Is UJ displayed?
NO
Is it deformed?
YES
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Check No. 14
Check the power supply
waveform.