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:
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
Communications bus and supply power
wiring guidelines
Table 7 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 wiring the controller's
communication buses and supply power.
Important:
Refer to the
N2 Modernization Guide
for Legacy N2 Controllers (LIT-12012005)
for
guidelines when you use this device on an N2
bus.
In addition to the guidelines in Table 7, observe the
following guidelines when you wire an FC or SA bus
and the 24 VAC supply power:
• Run
all
low-voltage wiring and cables separate
from high-voltage wiring.
• All FC and SA bus cables, regardless of wire size,
should be twisted, insulated, stranded copper
wire.
• Shielded cable is strongly recommended for all FC
and 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 FC and SA buses.
M4-CGM General Purpose Application Controllers Installation Guide
10
