Shielded Wire And Communication Bus Configuration; Damper Control Module (Zoning Systems Only) - Carrier Infinity SYSTXCCITC01-C Installation Instructions Manual

4.4.1. Shielded Wire and Communication Bus
Configuration
If the thermostat wiring will be located near or in parallel with high
voltage wiring, radio, TV or Ethernet wiring, then four conductor,
twisted-pair, shielded cable can be used to reduce or eliminate potential
interference. The shield wire should be connected to the C terminal, or
ground, AT THE INDOOR UNIT, ONLY. The shield wire should NOT
be connected to any terminal at the Infinity System Control. Connecting
the shield to ground at both ends can cause current loops in the shield,
reducing shield effectiveness.
Connect one pair of the two-pair (minimum) cable to the A and B
communication terminals, and another pair to the C and D terminals at
both ends of the cable. The shield wire should ONLY be connected at the
indoor equipment ground or C terminal. Note that some outdoor units
only require the A and B connections. See the outdoor unit installation
instructions for more information.
"Daisy chain" wiring, where each communicating component is wired
one after another, rather than all components connecting a in "star"
fashion to one point, is preferred. For wiring runs over 100 feet,
terminating with a 100 ohm resistor at each end of the chain can help to
avoid or mitigate electrical noise problems.
4.4.2. Damper Control Module (zoning systems
only)
When used, all wiring is run back to the Infinity System Damper Control
Module (SYSTXCC4ZC01). Select a location near the furnace or fan coil
where wiring from the control, each Remote Room Sensor or Smart
(Zone) Sensor, each damper actuator, and the equipment itself can come
together easily. The Damper Control Module is approved for indoor use
only and should never be installed with any of its components exposed to
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