Mitsubishi City Multi PURY-P400 Service Handbook page 120

Checking
Meaning, detecting method
code
6602 Transmission processor hardware
error
Transmission circuit bus-busy er-
6603
ror
1 Data transmission conflict;
Transmission cannot be per-
formed for 4~10 consecutive
minutes due to collision of data
transmission.
2 Data cannot be transmitted on
transmission line due to noise
for 4~10 consecutive minutes.
Note:
The address/attribute
shown on remote
controller indicates the
controller which has
detected error.
Cause
Checking method and processing
Transmission line
installed while turning
power source on?
NO
Check power source of indoor
unit.
220V ~ 240V?
YES
Check transmission line
work and shield finish
Ground fault or shield
contacted with transmission
line?
NO
System composition?
Single refrigerant
Plural refrigerant
system
system
Confirm supply power
connector CN40 of outdoor unit
YES
Modification of CN40
insertion method.
* For the investigation method, follow <Investiga-
Investigation of trans-
tion method of transmission wave shape/noise>
mission line noise
YES
Noise detected.
NO
Faulty controller of
generating unit
1) Due to constant short frequency
noise in the transmission line, trans-
mission processor is unable to trans-
mit signals.
2) Faulty controller of generating unit.
–119–
Checking method & Countermeasure
YES
Shut off the power source of outdoor/in-
door units/BC controller and turn it back on.
NO
Erroneous power
source work
YES
Erroneous transmis-
sion work
NO
Only 1 set with
CN40 inserted?
Investigation of the
cause of noise
a) Check transmission wave shape/noise on trans-
mission line by following <Investigation method
of transmission wave shape/noise>.
→ No noise indicates faulty controller of generat-
ing unit.
→ It noise detected, check the noise.
MELANS connected
system
Confirm supply power
connector CN40 of outdoor unit
CN40 inserted?
YES
Replace insertion
of CN40 to CN41
Modification of
faulty point