Cable And Wire Length Guidelines - Johnson Controls VMA1930 Installation Manual

Table 3: I/O terminal blocks, functions, ratings, requirements, and cables
Terminal block label
CONFIGURABLE
(Outputs)

Cable and wire length guidelines

The following table defines cable length guidelines
for the various wire sizes that may be used for
wiring low voltage (<30 V) input and outputs.
Table 4: Cable length guidelines
Guideline
A
B
C
10 VMA1930 VAV Controller Installation Guide
Terminal labels Function, ratings, and requirements
Analog Output - Voltage Mode (0–10 VDC)
10 VDC maximum output voltage
10 mA maximum output current
External 1k to 50k ohm load required
Binary Output 24 VAC Triac
OUTn Connects OUT to OCOM when activated.
External Power Source:
30 VAC maximum voltage to load
0.5 A maximum output current
1.3 A at 25% duty cycle
40 mA minimum load current
Analog Output Signal Common: All Configurable
Outputs defined as Analog Outputs share a
common, which is isolated from all other commons
except the Binary Input common.
OCOMn
Binary Output Signal Common: All Configurable
Outputs defined as Binary Outputs are isolated
from all other commons, including other
Configurable Output commons.
Wire size/Gauge and type
1.0 mm (18 AWG) stranded copper
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
0.5mm (24 AWG) stranded copper
107 m (350 ft) twisted wire
1.0 mm (18 AWG) stranded copper
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
0.5mm (24 AWG) stranded copper
107 m (350 ft) twisted wire
See Maximum cable length versus
load current to select wire size/
gauge.
Use stranded copper wire.
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 Maximum cable length
versus load current to determine
cable length.
Use twisted wire cable.
To determine wire size and
maximum cable length
See Guideline A in Table 4.
See Guideline C in Table 4.
Same as (Configurable) OUTn.
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