A4 T & B C A B L E T R AY M E TA L L I C C A B L E T R AY

—
T&B Cable tray
Introduction
Cable tray wiring systems offer significant advantages over conduit pipe and other
wiring systems. Cable tray is more cost efficient, more reliable, more adaptable
to changing needs and easier to maintain. In addition, its design does not contribute
to potential safety problems associated with other wiring systems.

The benefits of cable tray Direct cost savings are easy to calculate during the
An evaluation of the costs and benefits of various design phase of an installation, but the enormous
wiring systems should be done in the design advantages of cable tray may accrue only over time.
phase. Avoiding the system selection process or The system’s reliability, adaptability, ease of
deferring it until construction, often results in maintenance and inherent safety features result in
higher costs, scheduling delays and a system that many other types of cost savings, including:
will not meet future needs. • Lower engineering and maintenance costs
• Less need to reconfigure system as needs change
Selection of a wiring system that is not the most • Less down time for electrical and data
suitable for a particular application in terms of handling systems
cost, potential corrosion and electrical • Fewer environmental problems resulting from
considerations can lead to numerous problems, loss of power to essential equipment
including excessive initial cost, poor design,
faulty installation, extra maintenance, future power Reliability
outages and unnecessary safety concerns. Cable tray systems offer unsurpassed reliability,
resulting in less maintenance and down time –
Cost efficiency important considerations for all installations and
Extensive experience has shown that the overall especially for industries such as data
cost of a cable tray installation (including communications and financial services.
conductor, material and installation labor costs)
may be as much as 60% less than a comparable In addition, since cable tray is an open system,
conduit wiring system. moisture build-up problems are eliminated and
damage to cable insulation during installation
Cable tray systems, including trays, supports, is also greatly reduced.
fittings and other materials, are generally much
less expensive than conduit wiring systems. In
addition, major cost savings are generated by
the relative ease of installation. Labor costs of
installing a cable tray system can run up to 50%
less. Total cost savings will vary with the
complexity and size of the installation.
INTRODUCTION A5

Adaptability Cable tray and tray cable are also less susceptible
A major advantage of cable tray systems to fire loss than conduit. An external fire usually
derives from their adaptability to new needs results in damage to only a few feet of a cable tray
and technology. The pace of change in the system, while wire insulation inside a conduit
economy, constantly shifting competitive suffers significant damage and thermoplastic
pressures and rapid introduction of innovative insulation may actually fuse to the conduit.
technologies are all accelerating. More than ever
before, businesses must be prepared to quickly Safety
expand facilities, change products or introduce Cable wiring systems lack the inherent safety
new processes. The flexibility of the wiring concerns of conduit systems.
system is a key consideration.
By its nature, a conduit wiring system can serve as
Modifying a cable tray system or adding cables a flow-through for corrosive, explosive and toxic
to meet new needs is relatively easy because gases in the same way that it channels moisture.
cables can enter or exit a tray at any point, and
initial design considerations can build in extra The conduit installation process can also present
capacity as part of the planning process. Cable a safety issue for electricians. The process requires
tray’s inherent adaptability allows rewiring for that a conduit system be installed from one
future expansion, building redesign or new enclosure to another before pulling in the
technologies without disruption or need to conductors, leaving the electricians exposed to
replace the entire wiring system. any live, energized equipment that may be in the
enclosures. In contrast, installers can pull tray
Maintenance cables from near one termination enclosure to the
Cable tray wiring systems require less maintenance next before they are inserted into the enclosures
than conduit systems. When maintenance is and then terminated.
necessary, it is easier, less time-consuming and
less labor intensive. Finally, in installations where cable tray can be used
as the equipment grounding conductor (per NEC
The physical condition and status of both the standards), it is easy to visually check the system
cable tray and cables can be inspected visually, components as well as conduct checks for
something that is not possible with conduit electrical continuity.
systems. In addition, it is also easy to see if there
is sufficient capacity in the trays for additional
cables. As was noted above, changing or adding
cables can also be accomplished easily.

Another comparative benefit of cable tray systems