VAV-SVN03A-EN
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Communication Link Wiring
The VariTrac Central Control Panel communication link (TB2-10, 11, and 12)
connects the CCP, UCM dampers, communicating sensor/bypass damper
control assembly, and Voyager/Reliatel rooftop units. Field wiring for the
communication link must meet the following requirements:
• All wiring must be in accordance with the National Electrical Code and
local codes.
• Communication link wiring must be Level 4 22 AWG twisted, shielded pair
wire (meets or exceeds Trane specifications. See wiring specifications
sections in this manual for further information).
• The maximum total wire length is 3,500 feet for the communication link.
At the VariTrac Central Control Panel, the communication link wires must be
connected to Terminals TB2-10 (+) and TB2-11
(−
). Refer to Figure 17. This
connection is polarity sensitive.
IMPORTANT
Connections between lengths of link wiring should be soldered and taped.
Wire nuts are not acceptable.
CAUTION
Connecting the communication link with reversed polarity will lead to
system malfunction and possible equipment damage.
The shield on the communication link wiring must be connected to TB2-12.
The shield wire should be spliced with the shield from the next section of
communication link wiring at every junction. Tape each splice to prevent any
contact between the shield and ground. The shield should be cut and taped
back at the end of the link.
Communication link wiring cannot pass between buildings.
IMPORTANT
Improper communication link shield connections will lead to system
malfunction.
IMPORTANT
Improper communication link routing will lead to system malfunction.
Connect UCMs on the communication link in a daisy-chain configuration.
With this configuration, it is easier to solve communication problems by
isolating portions of the communication link. See Figure 16 for an example
of a daisy-chain configuration.
Getting Started
