Johnson Controls FEC26 Series, Installation Manual

Page: 10 / 24

Table 3: Terminal blocks, functions, ratings, requirements, and cables
Terminal block label Terminal label Function, ratings, requirements
Determine wire size and maximum cable
length
Analog Output - Voltage Mode (0–10 VDC)
10 VDC maximum output voltage
10 mA maximum output current
Required an external load of 1,000 ohms or
more.
See Guideline A in Table 4.
OUT n
Binary Output - 24 VAC Triac (External
Power Source only)
Connects OUT
n to OCOM n when activated.
External Power Source Requirements:
30 VAC maximum output voltage
0.5 A maximum output current
1.3 A at 25% duty cycle
40 mA minimum load current
See Guideline C in Table 4.
Analog Output Signal Common All
Configurable Outputs (COs) defined as
Analog Outputs (AOs) are isolated from all
other commons except the Binary Input
common.
CONFIGURABLE
(Outputs)
OCOM n
Binary Output Signal Common All
Configurable Outputs (COs) defined as
Binary Outputs are isolated from all other
commons, including other CO commons.
Same as (Configurable) OUT n .
Cable and wire length guidelines
Table 4 defines cable length guidelines for the various
wire sizes that may be used for wiring low-voltage (<30 V)
input and outputs.
Cable length guidelines for recommended
wire sizes table
Table 4: Cable length guidelines for recommended wire sizes for low-voltage (<30 V) Inputs and Outputs
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 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.
FEC26 Field Equipment Controllers Installation Guide 10