LC700 – Users Guide
4.2
Aggroup the cables that fit in this
description
Categories Examples
Control and AC Power Supply
High Power Cables which are more resistant to
electric noises than conductors of the Category 2.
They can, also, generate more noise to be
induced in the adjacent cables.
Category 1
- AC Power lines for power supplies and I/O circuits;
- AC high power digital I/O lines - to connect AC I/O modules,
classified for high power and high noise immunity;
- DC digital I/O high power lines - to connect DC I/O modules
classified for high power or input circuits with filters with a big time
constant, for high rejection to noise. Typically for connection with
dry contact key, relay and solenoid valve.
Sign & Communication
Low power cables which are less resistant to
electric noises than Category 1 cables. They
should also generate less noise that may be
induced in the adjacent cables (they are
connected to sensors and actuators relatively
close to the I/O modules).
Category 2
- Analog I/O lines and DC power lines for analog circuits;
- AC/DC low power lines of digital I/O to connect I/O modules that
are classified for low power, such as output modules of low power;
- DC Digital I/O lines for low power: they are used to connect DC
I/O modules classified for low power. They have input circuits with
filters of low time constant to detect pulses. They typically are
connected to equipments similar to keys, photoelectric sensors and
codifiers;
- Communication cables - for connection among CPUs or for
communication interface modules, programming terminals,
computers, etc.
Inside the Panel
They interconnect the components of the system
inside the panel.
Category 3
- DC power cables for low power: power cables for Rack;
- Communication cables: cables for connection of system
components inside the same panel, ICP-700-D3, Flat Cable.
Table 6.1 – Cables Categories
Conductors Positioning
To reduce the transference of conductor noises from one another, maintain the electrically noisy
wire, as AC power cables and digital outputs cables physically separated from the lines of low level,
as cables of analog inputs and outputs or communication cables. Follow these procedures (Table
4.2) when positioning wires and cables (inside or outside of a panel).
NOTE
These procedures are only for noise immunity.
Follow the local standards for safety requirements.
Category Category According to these Procedures
Category 1
- These conductors can be placed in the same duct or conduit with the power conductors of machines up
to 600Vac (feeding equipments up to 100 hp).
Category 2
- If these conductors need to cross the power lines, this should be done at right angles.
- Keep them far, at least, 5 ft (1.5m) from high tension panels or RF radiation sources / microwaves.
- If the conductor is in a metal duct or conduit, each segment must be connected to the adjacent segment,
so that it has continuity along its length, and must be connected at the panel input point.
- Appropriate shield (where applicable) and direct it in a duct separate from the conductors of category 1.
- If it is in a adjacent metal duct or conduit, keep it at least 0.08m (3 in) away from the conductors of the
category 1 of less than 20A; 0,15m (6 in) of AC power lines with 20A or above, but up to 100 kVA and
0.3m (1 ft) of AC power lines larger than 100 kVA.
- If it is not in a continuous duct or conduit, keep it at least 0.15m (6 in) away from conductors of the
category 1 of less than 20A; 0.3m (1 ft) of AC power lines 20A or above, but only up to 100 kVA and 0.6m
(2 ft) of AC power lines larger than 100 kVA.
Category 3
- Direct the conductors in ducts separated from the category 1 conductors with the same striped spacing
as the category 2 conductors, where it is possible.
Table 4.2 – Procedures for Positioning the Cables from Noise Protection
IMPORTANT
These procedures presuppose that the user will follow the procedures for Surge-suppression
guide lines (Chapter 3 starting on page 3.70).
Although these rules apply to most installations, some electrically severe environments may
need additional precautions.
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