Johnson Controls FX-PCX2721 User Manual

Cable and wire length guidelines
The following table defines cable length guidelines for the various wire sizes that may be used for
wiring low-voltage (<30 V) input and outputs.
Table 4: Cable length guidelines
Guideline 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 8 to select wire
size/gauge. Use stranded
copper wire.
See Figure 8 to
determine cable
length. Use twisted
wire cable.
N/A
Maximum cable length versus load current
Use the following figure to estimate the maximum cable length relative to the wire size and the
load current (in mA) when wiring inputs and outputs.
Note: The following information applies to low-voltage (<30 V) inputs and outputs only.
FX-PCX2721 Expansion Input/Output Module Installation Instructions16

Johnson Controls FX-PCX2721 Specifications

General

Brand	Johnson Controls
Model	FX-PCX2721
Category	I/O Systems
Language	English