Wiring Communication; Terminal Designations; System Wiring Overview; Wiring Requirements - Johnson Controls Hx 3 S1-THXU430W Installation Manual

5407934-UIM-C-1119
SECTION IV: WIRING COMMUNICATION
If using the thermostat with variable capacity outdoor equipment, DO
NOT connect to the R terminal of the outdoor unit control board.
All wiring must comply with local electrical codes and ordinances. See
Table 2 for terminal designations.
TABLE 2: Terminal Designations
Signal
Data
Low-voltage power hot
Low-voltage power common and data ground
Data

WIRING REQUIREMENTS

Use standard 18 AWG thermostat wires to connect the communicating
HVAC system and the conventional HVAC system.
Special (shielded) cable is not typically required. As with all communicat-
ing devices, it is a good idea to keep wiring at least 1 ft away from large
inductive loads, for example, electronic air cleaners and motors. If these
wiring practices are ignored, it may introduce electrical interference
(noise), which can cause erratic system operation.
There may be installation applications where large inductive loads
cannot be avoided. In these cases, use shielded wire in proximity to
the inductive loads to ensure proper system functionality.

SYSTEM WIRING OVERVIEW

IMPORTANT: The communicating system requires four wires to oper-
ate. If installing a communicating system, ensure to supply at least
four wires to each unit/control. For a simple diagram of the ideal wiring
path, see Figure 3.
8
WARNING
!
NOTICE
Definition
Non-inverted signal
24 VAC (Hot)
24 VAC (Common)
Inverted signal
Johnson Controls Ducted Systems
Label
A (+)
R
C
B (-)