LG ACHH Series Manual page 58

Error code check
Error number
09 Remote communication error
n Failure diagnosis method
Is power of
remote communication
equipment supplied?
Yes
Is polarity of a
communication line
properly performed?
Yes
Is an address
setting between remote
communication equipment
and a chiller board
properly performed?
Yes
Is a communication
speed setting between
remote communication
equipment and a chiller
board agreed?
Yes
Is a communication
period between remote
communication equipment
and a chiller board
within 30 seconds?
Yes
Replace a chiller board
Errors
In case where a communication is not
performed for 30 seconds after occur-
ring the first communication between a
chiller board and external communica-
Permit power to remote
No
communication equipment
[Note 1.]
Check the connection
No
status by referring to a
connection map [Note 2]
Agree a chiller board
No
address and a remote
communication equipment
address value [Note 3.]
Adjust communication
No
speed of remote
communication equipment
[Note 4].
Request that a
communication period with
No
remote communication
equipment should be within
30 seconds [Note 5].
Meaning
tion equipment
[Note 1] Confirm whether or not the power of remote auto-
matic control equipment communicating with a chiller board
or DDC is normally supplied
[Note 2] Providing 485 communication is not communicated
in case where polarity doesn't match
Match providing connection map polarity A and B with the
polarity of remote automatic control equipment or 485 com-
munication terminal of DDC
Regarding connection status of external equipment, confirm
the position of polarity by asking a person in charge of an
automatic control or BMS company
[Note 3] Refer to the HMI communication error part regard-
ing an address setting method since it is the same with the
address setting method of HMI communication error.
Regarding an address setting of external equipment, confirm
the address setting by asking a person in charge of an auto-
matic control or BMS company
[Note 4] A communication condition provided by a chiller
board is following as below
- Physical Layer: RS-485 Serial Line
- Mode: MODBUS RTU Mode
- Baud Rate: 9 600
- Parity: None Parity
- 1 Stop Bit
Agree the communication condition by providing to a person
in charge of remote communication equipment
[Note 5] Request to a person in charge of remote communi-
cation equipment since an error is not occurred when com-
municating with a chiller board at least once in 30 seconds at
the remote communication equipment
- 58 -
Main cause of occurrence
- Communication line polarity defect
- External communication equipment
power abnormality
- Chiller PCB defect