Trane Air-Fi WCS-SB Installation, Operation And Maintenance Manual page 28

WCI Installation
7. Restore power to the controller.
Important: The WCI must be wired to the controller prior to power up in order to establish network
28
Notes:
• If the wiring harness does not provide enough length for a proper mounting location of
the WCI, use Trane communication cable as a substitute. Trane "purple wire", is 2-
conductor, 18 AWG stranded, 25pF/ft. cable with braided shielding. The Trane purple
cable is required for the communication link, and a separate shielded or unshielded two
conductor 18 - 22 AWG cable is required for 24V AC/DC power. (It's not necessary to
use Trane purple wire for the power. It is required only for communication.) Using
separate cables for power and communication is desirable to reduce interference, which
can cause intermittent communication over long wire runs. The cable length between the
WCI and a controller cannot exceed 656 feet (200 m).
When Trane purple shielded cable is used for communication, the braided shielding wire
must be grounded on the UC, BCI-I, PM014, or BCI-R end only. On UC, BCI-I, or PM014
use a chassis ground termination (
BCI2-I or UC400–B you will have to ground the braided shielding wire to the machine
chassis, possibly under a board mounting screw head, since the controller has no
chassis ground termination available. The WCI end of the cable will have the shielding
braid unconnected and taped back.
If shielded cable is used for power, it is optional whether to ground the shielding braid or
just tape it back. If you choose to ground the shielding braid, it will be grounded at the
controller end at the same point where the Trane purple communication shielding was
terminated. The WCI end of the power cable will have the shielding braid unconnected
and taped back.
• Avoid running the communication cable parallel and up against any high voltage wiring
or electric motors in the machine or building as this causes noise to be induced into the
communication wire and can cause intermittent communication of the WCI. Try to keep
the communication cable as far away from high voltage wiring or electric motors as
possible. It is acceptable to run the communication cable perpendicular to high voltage
wires as this will not induce noise into the communication cable.
• When wiring a WCI, always power the WCI from the controller if possible. If it is not
possible to power the WCI from the controller, then remote powering of the WCI is
permissible. A case where it is permissible to use remote powering might be when trying
to re-use an existing 2 conductor cable. In this case the existing cable will be used for
communication and the WCI would need to have 24V AC/DC power supplied remotely.
• To save on installation labor, we recommend Windy City Wire MegaPack, part number
TRNMEGAPAC, for installation of Air-Fi® Wireless Coordinator WCIs (Wireless
Communication Interfaces). It includes 18/2 Shielded Low-capacitance Comm (BACnet)
cable (052003) + 18/2 Shielded Plenum (power) cable (002320) in a single carton.
Minimum cable length is 1000".
To wire the WCI to UC, BCI, BCI2, Symbio™ or SC+ follow diagrams on the following pages.
For detailed information, refer to the BACnet MS/TP Wiring and Link Performance Best Practices
and Troubleshooting Guide (BAS-SVX51*-EN).
The network is ready to be formed. Refer to
communication. If you cannot apply power to the WCI and the controller at the same time,
apply power to the WCI first by using a remote power source.
) on the controller. However, on a BCI-R, BCI2-R,
"Establishing an Air-Fi® Network," p. 60.
BAS-SVX40K-EN