Mitsubishi Electric PQHY-P200YLM-A Service Handbook page 313

[ IX Troubleshooting ]
1. Error Code
6602
Transmission processor hardware error
2. Error definition and error detection method
Although "0" was surely transmitted by the transmission processor, "1" is displayed on the transmission line.
The address/attribute appeared on the display on the remote controller indicates the controller where an error oc-
curred.
3. Cause
1) When the wiring work of or the polarity of either the indoor or heat source transmission 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 detected.
2) Grounding fault of the transmission line
3) When grouping the indoor units that are connected to different heat source units, the male power supply connectors on the
multiple heat source units are connected to the female power supply switch connector (CN40).
4) When the power supply unit for transmission lines is used in the system connected with MELANS, the male power supply
connector is connected to the female power supply switch connector (CN40) on the heat source 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
heat source units or in case of the system connected with MELANS)
4. Check method and remedy
HWE15060
Is the transmission line work
performed while the power is on?
NO
Check the power source of the indoor unit.
NO
198 / 264V?
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-heat source-unit Multiple-heat source-unit
system system
Confirm that the power supply
connector on the heat source
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 heat source 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
Investigation into the
Noise exist?
cause of the noise
NO
Controller failure of the
source of the error
YES
Turn off the power source of heat source-
indoor units, and turn them on again.
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 heat source
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
Correct the error.
- 304 -
YES
GB