I/O terminal blocks, ratings, and
requirements table
Table 2: IOM3733 terminal blocks, functions, ratings, requirements, and cables
Terminal block label Terminal
label
Function, ratings, requirements
Determine wire size and
maximum cable length
Binary Input - Dry Contact Maintained Mode
0.01 second minimum pulse width
Internal 16V, 10K ohm pull up
IN
n
Binary Input - Pulse Counter/Accumulator Mode
0.01 second minimum pulse width
(50 Hz at 50% duty cycle)
Internal 16V, 10K ohm pull up
BINARY INPUT
ICOM
n
Binary Input Common
for all Binary Input (IN) terminals
See Guideline A in Table 3.
OUT
n
Binary Output - 24 VAC Triac (External Power)
Connects OUTn to OCOMn 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
BINARY OUPUT
(External Power Source
Only)
OCOM
n
Binary Output Common
(for OUT
n
terminal)
See Guideline C in Table 3.
Cable length guidelines for required wire
sizes
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 3: Cable length guidelines for required 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 7 to select wire size/gauge.
Use stranded copper wire
See Figure 7 to determine
cable length. Use twisted
wire cable.
N/A
Maximum wire length by current and
wire size
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.
This figure applies to low-voltage (<30 V) inputs and
outputs only.
IOM3733 Input/Output Module Installation Guide
7