Johnson Controls FAC4911 User Manual

Table 4: Cable length guidelines for recommended wire sizes for low-voltage (<30 V) Inputs and Outputs
Wire size/Gauge and type Maximum cable length and
type
Assumptions
1.0 mm (18 AWG) stranded copper 457 m (1,500 ft) twisted wire
0.8 mm (20 AWG) stranded copper 297 m (975 ft) twisted wire
0.6 mm (22 AWG) stranded copper 183 m (600 ft) twisted wire
A
0.5 mm (24 AWG) stranded copper 107 m (350 ft) twisted wire
100 mV maximum voltage drop
Depending on cable and the
connected input or output device, you
may have to define an offset in the
setup software for the input or output
point.
1.0 mm (18 AWG) stranded copper 229 m (750 ft) twisted wire
0.8 mm (20 AWG) stranded copper 137 m (450 ft) twisted wire
0.6 mm (22 AWG) stranded copper 91 m (300 ft) twisted wire
B
0.5 mm (24 AWG) stranded copper 61 m (200 ft) twisted wire
100 mV maximum voltage drop
Depending on cable and the
connected input or output device, you
may have to define an offset in the
setup software for the input or output
point.
C See Figure 6 to select wire size/gauge. Use
stranded copper wire
See Figure 6 to determine cable
length. Use twisted wire cable.
N/A
Maximum cable length versus load
current
Use Figure 6 to estimate the maximum cable length
relative to the wire size and the load current (in mA) when
wiring inputs and outputs.
Note: Figure 6 applies to low-voltage (<30 V) inputs
and outputs only.
Figure 6: Maximum wire length for low-voltage (<30 V)
Inputs and Outputs by current and wire size
Communications bus and supply power
wiring guidelines
The following table provides information about
the functions, ratings, and requirements for the
communication bus and supply power terminals. The
table also provides guidelines for wire sizes, cable types,
and cable lengths for when you wire the controller's
communication buses and supply power.
In addition, observe these guidelines when you wire an FC
bus and the 24 VAC supply power:
• Run all low-voltage wiring and cables separate from
high-voltage wiring.
• All SA bus cables, regardless of wire size, must be
twisted, insulated, stranded copper wire.
• Shielded cable is strongly recommended for all SA bus
cables.
• Refer to the MS/TP Communications Bus Technical
Bulletin (LIT-12011034) for detailed information
regarding wire size and cable length requirements for
SA buses.
FAC4911 Advanced Application Field Equipment Controller Installation Guide 9

Johnson Controls FAC4911 Specifications

General

Brand	Johnson Controls
Model	FAC4911
Category	Controller
Language	English