Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 265

[ IX Troubleshooting ]
Error
Error definition and error detec-
Code tion method
6602 Transmission processor hard-
ware error
Although "0" was surely trans-
mitted by the transmission pro-
cessor, "1" is displayed on the
transmission line.
The address/attribute ap-
peared on the display on
the remote controller in-
dicates the controller
where an error oc-
curred.
Check method and remedy
(1) When the wiring work of or the polarity of either the indoor or outdoor trans-
mission line is performed or is changed while the power is on, the transmitted
data will collide, the wave shape will be changed, and an error will be detect-
ed.
(2) Grounding fault of the transmission line
(3) When grouping the indoor units that are connected to different outdoor units,
the male power supply connectors on the multiple outdoor units are connect-
ed to the female power supply switch connector (CN40).
(4) When the power supply unit for transmission lines is used in the system con-
nected with MELANS, the male power supply connector is connected to the
female power supply switch connector (CN40) on the outdoor unit.
(5) Controller failure of the source of the error
(6) When the transmission data is changed due to the noise on the transmission
line
(7) Voltage is not applied on the transmission line for centralized control (in case
of grouped indoor units connected to different outdoor units or in case of the
system connected with MELANS)
Check method and remedy
Is the transmission line work
performed while the power is on?
NO
Check the power source of the indoor unit.
208 / 230V?
YES
Check the transmission line work is performed
and the shielded wire is treated properly.
Grounding fault or does the shielded
wire contact with the transmission line?
NO
System ?
Single-outdoor-unit system Multiple-outdoor-unit system
Confirm that the power supply
connector on the outdoor
unit is not plugged into CN40.
Is the male power supply connector
YES
connected to the female power supply
switch connector (CN40) on only one
of the outdoor unit?
Tightly reconnect the male power
supply connector to the female
power supply switch connector (CN40).
Investigation into the
*For the investigation method, follow
transmission line noise
<Investigation method of transmission wave shape/noise>
YES
Noise exist?
NO
Controller failure of the
source of the error
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YES
Turn off the power source of outdoor/indoor
units, and turn them on again.
NO
Faulty power source work
YES
Improper transmission line work
System with the power supply
unit for transmission lines
Confirm that the power supply
connector on the outdoor
unit is not plugged into CN40.
Is the male power supply connector
NO
connected to the female power supply
switch connector (CN40) ?
NO
Disconnect the male
power supply on
CN40 and connect it to CN41
Investigation into the
cause of the noise
Correct the error.
YES