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.
Note:
Figure 8
applies to low-voltage (<30 V) inputs and outputs only.
Figure 8: Maximum Wire Length for Low-Voltage (<30 V) Inputs and Outputs by Current and Wire Size
SA/FC Bus and Supply Power Wiring Guidelines
Table 5
provides information about the functions, ratings, and requirements for the communication bus and supply
power terminals; and guidelines for wire sizes, cable types, and cable lengths when wiring the controller's
communication buses and supply power.
In addition to the guidelines in
Table 5
, observe these guidelines when wiring an SA or FC bus and the 24 VAC
supply power:
•
Run all low-voltage wiring and cables separate from high-voltage wiring.
•
All SA and FC bus cables, regardless of wire size, should be twisted, insulated, stranded copper wire.
•
Shielded cable is strongly recommended for all SA and FC bus cables.
•
Refer to the
MS/TP Communications Bus Technical Bulletin (LIT-12011034)
for detailed information about wire
size and cable length requirements for the SA and FC buses.
18
FEC1611 and FEC1621 Field Equipment Controller Installation Instructions