Samsung DVM S VRF Technical Data Book page 133

10. Installation
Specification of Cable and Connecting method
f For communication cable, 2-core sheathed vinyl cable should be used which satisfies nominal area of
0.75~1.25mm2 thickness. If 2 or more than 3 communication are connected with one cable which is 4, 6 or more
strands, communication malfunction could be caused. Only 2-core sheathed vinyl cable should be used for one
communication line.
f Maximum connecting length is limited to 1000 m, so you should follow this limit not to cause malfunction of
communication.
f Maximum number of units that can be connected to the outdoor main unit is 64, so do not exceed this limit.
f Communication cable should be connected in series as in the figure below, and malfunction of communication
can be occur if many units are connected to the same terminal.
f Communication cable between indoor and outdoor units and communication cable between outdoor units has no
polarity.
Main unit
Communication
cable
Power •
ground cable
Sub unit
ELCB
or
MCCB+
ELB
Ground cable
Communication
cable between
outdoor units
Power cable
Sub unit
ELCB
or
MCCB+
ELB
Ground cable
Communication
cable between
outdoor units
Power cable
Main unit
Sub unit
ELCB
or
MCCB+
ELB
Protection
tube
Ground cable
Power cable
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