Parker H Series, Инструкция по установке и обслуживанию

Страница: 97 / 344

Industrial Automation Wiring and Grounding Guidelines E115P
2
Raceway Layout Considerations
The raceway layout of a system is reflective of where the
different types of I/O modules are placed in I/O chassis.
Therefore, you should determine I/O-module placement
prior to any layout and routing of wires. However, when
planning your I/O-module placement, segregate the
modules based upon the conductor categories published
for each I/O module so that you can follow these guidelines.
Also, all conductors (AC or DC) in the same raceway
must be insulated for the highest voltage applied to any
one of the conductors in the raceway. These guidelines
coincide with the guidelines for “the installation of electrical
equipment to minimize electrical noise inputs to controllers
from external sources” in IEEE standard 518-1982.
Categorize Conductors
Segregate all wires and cables into the following three
categories (Table A). Refer to the publication for each
specific I/O module or block for individual conductor-
category classification of each I/O line.
Table A
Follow these Guidelines for Grouping Conductors with Respect to Noise
Into this
Group conductor cables fitting this description category: Examples:
Control and AC Power — high-power conductors that Category 1 • AC power lines for power supplies and I/O circuits.
are more tolerant of electrical noise than category 2 • High-power digital AC I/O lines — to connect AC I/O
conductors and may also cause more noise to be modules rated for high power and high noise immunity.
picked up by adjacent conductors • High-power digital DC I/O lines — to connect DC I/O
modules rated for high power or with input circuits with
• Corresponds to IEEE levels 3 (low susceptibility) long time-constant filters for high noise rejection. They
and 4 (power) typically connect devices such as hard-contact switches,
relays, and solenoids.
Signal and Communication — low-power conductors Category 2 • Analog I/O lines and DC power lines for analog circuits.
that are less tolerant of electrical noise than • Low-power digital AC/DC I/O lines — to connect to I/O
category-1 conductors and should also cause less modules that are rated for low power such as low-power
noise to be picked up by adjacent conductors (they contact-output modules.
connect to sensors and actuators relatively close to • Low-power digital DC I/O lines — to connect to DC I/O
the I/O modules) modules that are rated for low power and have input
circuits with short time-constant filters to detect short
• Corresponds to IEEE levels 1 (high susceptibility) pulses. They typically connect to devices such as
and 2 (medium susceptibility) proximity switches, photo-electric sensors, TTL devices,
and encoders.
• Communication cables (ControlNet, DeviceNet, RS-232-C
cables) — to connect between processors or to I/O
adapter modules, programming terminals, computers, or
data terminals.
Intra-enclosure — interconnect the system Category 3 • Low-voltage DC power cables — provide backplane power
components within an enclosure to the system components.
• Corresponds to IEEE levels 1 (high susceptibility) • Communication cables — to connect between system
and 2 (medium susceptibility) components within the same enclosure.