6602
Faulty controller of
generating unit
YES
YES
Erroneous power
source work
Erroneous transmission
work
NO
NO
YES
NO
NO
NO
YES
YES
YES
Transmission line
installed while turning
power source on? Shut off the power source of outdoor/in-
door units/BC controller and make it again.
Check power source of in-
door unit.
187V ~ 253V?
Check transmission line
work and shield finish
Ground fault or shield
contacted with transmission
line?
System composition?
Single refrigerant system Plural refrigerant system
Confirm supply power con-
nector CN40 of outdoor unit
Only 1 set with
CN40 inserted?
Modification of CN40
insertion method
Investigation of trans-
mission line noise
Noise exist? Investigation of the
cause of noise
✻For the investigation method, follow <Investigation
method of transmission wave shape/noise>.
Modification of
faulty point
Replace insertion
of CN40 to CN41
CN40 inserted?
Confirm supply power con-
nector CN40 of outdoor unit
MELANS connected
system
Checking method and processing
6603 a) Check transmission wave shape/noise on
transmission line by following <Investigation
method of transmission wave shape/noise>.
→No noise indicates faulty controller of generat-
ing unit.
→Noise if existed, check the noise.
Transmission processor
hardware error
Transmission circuit bus-
busy error
1Collision of data transmis-
sion:
Transmission can not be per-
formed for 4~10 consecutive
minutes due to collision of
data transmission.
2Data can not be transmitted
on transmission line due to
noise for 4~10 consecutive
minutes.
Note:
The address/attribute
shown on remote con-
troller indicates the con-
troller which has de-
tected error.
1) As the voltage of short frequency
like noise is mixed in transmission
line continuously, transmission
processor can not transmit.
2) Faulty controller of generating
unit.
Faulty controller of
generating unit
Checking
code
Meaning, detecting method Cause Checking method & Countermeasure
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75
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