PEAK® OEM 32 24 Volt SMART Equipment Controller Installation Instructions
21
Maximum cable length versus load current
See Figure 12 to estimate the maximum cable length relative to the wire size and the load current (in mA) when you
wire inputs and outputs.
Note:
Figure 12 applies to low-voltage (<30 V) inputs and outputs only. The required wire size and length for
high-voltage (>30 V) relay outputs is determined by the load connected to the relay and local electrical codes.
Figure 12: 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 7 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 you wire the controller's
communication buses and supply power.
In addition to the guidelines in Table 7, follow these guidelines when you wire 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.
•
It is best practice to use shielded cable for all SA and FC bus cables.
B
1.5 mm
2
(32 AWG)
stranded copper
229 m (750 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.
0.8 mm
2
(20 AWG)
stranded copper
137 m (450 ft) twisted
wire
0.6 mm
2
(22 AWG)
stranded copper
91 m (300 ft) twisted
wire
N/A (24 AWG)
stranded copper
61 m (200 ft) twisted
wire
C
See Figure 12 to
select wire size/
gauge. Use stranded
copper wire.
See Figure 12 to
determine cable length.
Use twisted wire cable.
N/A
Table 6: Cable length guidelines for recommended wire sizes for low-voltage (<30 V) inputs and outputs
(Part 2 of 2)
Guidelines
Wire size/gauge and
type
Maximum cable
length and type
Assumptions
450
500
400
350
300
250
200
150
100
50
0
0 m 0 ft
(
)
15.2 m 50 ft
(
)
30.5 m 100 ft
(
)
45.7 m (150 ft)
61 m 200 ft
(
)
76.2 m 250 ft
(
)
91.4 m 300 ft
(
)
106.7 m 350 ft
(
)
121.9 m 400 ft
(
)
137.2 m 450 ft
(
)
Load Current (mA)
Length
FI
G:
fe
c_
wi
re
_s
iz
e_
le
ng
th
1.5 mm (18 AWG)
2
0.8 mm (20 AWG)
0.6 mm (22 AWG)
N/A (24 AWG )
