Gree GMV-Pdm450W/NaB-M

DC Inverter Multi
VRF Service Manual
155
5 COMMON TROUBLES DURING DEBUGGING
5�1 Communication
Abnormal communication is the main and common trouble in communication system which mainly consists of the
following groups.
S/N Class Trouble Possible Cause Troubleshooting
1
Abnormal
communication
between
indoor unit and
outdoor unit
“E6”
communication
error codes are
displayed on
all indoor and
outdoor units.
Communication wire between indoor and
outdoor unit is not connected.
Outdoor unit
Indoor unit
Refrigerant pipe
Communication cable
E6
Check if communication
wire is connected.
2
The polarities of communication wire connecting
indoor and outdoor units are not inconsistent.
Outdoor unit
Indoor unit
Communication cable
E6
B
A
PCB
PCB
A
B
Exchange the polarities of plugs
of communication wire.
3
The communication wire connecting indoor
unit to outdoor unit is short circuit.
Outdoor unit
Indoor unit
Communication cable
E6
A
B
PCB
PCB
A
B
Check it with universal meter
and if it is short circuit, replace
the communication wire
4
Address of indoor unit, wired controller
or outdoor unit is not correctly set.
Check if their addresses
are set correctly.
5
Addresses of main board of outdoor unit
or patch board are not correctly set.
Check if their addresses
are correctly set.
6
Communication
between indoor
unit and outdoor
unit is not
continuously
The communication wire connecting outdoor
unit and indoor unit is short circuit or it
contacts metal when it is damaged
Outdoor unit
Indoor unit
Communication cable
E6
A
B
PCB
PCB
A
B
Eath
Check it with universal meter
and if it is short circuit, replace
the communication wire.
Seperately mesure the two
polarities of communication wire
and check if it is shorted to earth.
7
The ground wire which shield communication
wire is not efciently earthed.
Efciently connect the ground wire.