Johnson Controls FEC16 Series Installation Instructions Manual page 9

Table 2 defines cable length guidelines for the various
wire sizes that may be used for input and output wiring.
Table 2: Cable Length Guidelines for Recommended Wire Sizes
Guideline Wire Size/Gauge and Type
A
2
1.5 mm (18 AWG) stranded copper
0.8 mm (20 AWG) stranded copper
0.6 mm (22 AWG) stranded copper
N/A (24 AWG) stranded copper
B
2
1.5 mm (18 AWG) stranded copper
0.8 mm (20 AWG) stranded copper
0.6 mm (22 AWG) stranded copper
N/A (24 AWG) stranded copper
C See Figure 8 to select wire size/gauge.
Use stranded copper wire.
Maximum Cable Length versus Load Current
Use Figure 8 to estimate the maximum cable length
relative to the wire size and the load current (in mA)
when wiring inputs and outputs.
FEC16 Extended Temperature Field Equipment Controller Installation Instructions
Figure 8: Maximum Wire Length by Current and Wire Size
Maximum Cable Length
and Type
457 m (1,500 ft) twisted wire
297 m (975 ft) twisted wire
183 m (600 ft) twisted wire
107 m (350 ft) twisted wire
229 m (750 ft) twisted wire
137 m (450 ft) twisted wire
91 m (300 ft) twisted wire
61 m (200 ft) twisted wire
See Figure 8 to determine
cable length. Use twisted
wire cable.
Assumptions
100 mV maximum voltage drop
Depending on the cable length and
the connected input or output device,
you may have to define an offset in
the setup software for the input or
output point.
100 mV maximum voltage drop
Depending on the cable length and
the connected input or output device,
you may have to define an offset in
the setup software for the input or
output point.
N/A
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