Communication Wiring Connection - McQuay MDS 30 Installation Manual

7.4 Communication wiring connection


For single unit connection.
Outdoor unit
Control box
Screen
layer
Main PCB
Connection
port
To network or central
control (optional)

For master and slave units connection.
Outdoor unit
Screen
Master unit
layer
Main PCB
Connection
port
To network or central
control (optional)

Example of wrong connection.
PCB
Connection port
A
com1
B
A
B
Neglect to
connect
Outdoor unit
Control box
Main PCB
Connection
port
22
Indoor unit 1
Control box
PCB
Connection port
A
com1
B A B
Communication cable
Slave unit
Main PCB
Connection
port
Communication cable
PCB
Connection port
A
A B
B
Connect A with B, wrong
Control box
Screen
layer
Communication cable
Communication cable
Indoor unit 2
Control box
PCB
Connection port
A
com1
A B
B
Communication cable
Indoor unit 1
Control box
PCB
Connection port
A
com1
B
A B
Communication cable
PCB
Connection port
A com1
A B
B
Indoor unit 1
PCB
Connection port
A
com1
A B
B
not bus structrue,connection cable
should be layed as bus structure
Control box
Connection port
A
A
B
Communication cable
Indoor unit 2
Control box Control box
PCB
Connection port
A
com1
B
A B
Communication cable
Screen layer must be
grounded with outdoor unit
Control box
Main PCB
Connection
port
Indoor unit 2
Control box
PCB
Connection port
A
com1
A B
B
Installation Manual IM-MDS_(i)
Indoor unit i
PCB
JP1
com1
B
JP 1 of last unit on
main bus should be on
Indoor unit i
PCB
Connection port
A
JP1
com1
B
A B
JP 1 of last unit on
main bus should be on