Page 14 - IEC Insights Nov-Dec21_WEB

FEATURE

Selecting Materials

Once a system is determined, material selection and finish should be chosen based on the
environmental conditions and economic considerations for the project. Different systems
will offer different finishing options, but there are a variety that can be considered.
Finishes can include:
Choosing PRE-GALVANIZED STEEL
the proper Mill-galvanized steel (ASTM-A-653-G90 CS) is zinc coated by a hot dip process. A

system for the steel strip is fed through a continuous zinc coater which cleans, fluxes and coats the
steel with molten zinc. Pre-galvanized steel is best used for indoor applications or
application outdoor environments with mild conditions.
takes careful
HOT DIP STEEL GALVANIZED AFTER FABRICATION
understanding In hot dip galvanizing after fabrication (HDGAF), the finished section is immersed in
of all aspects of a bath of molten zinc (ASTM 123). This method results in complete zinc coverage and
a thicker coating than pre-galvanized or electro-plated steel. The zinc coating also
the installation covers any welds in the tray or fittings. This is the coating of choice for applications
to choose the where protection from severe corrosion is a design factor.
right cable tray STAINLESS STEEL

for the job. Type 304 and Type 316 stainless steel material in accordance with ASTM A-240 is
best for applications demanding high corrosion-resistance.

ALUMINUM
Aluminum material is the most commonly used ladder tray material, in accordance
with AA-6063-T6. It’s suitable for most indoor and outdoor applications and
associated with lower total installation costs.

FIBERGLASS
Fiberglass is inherently chemical resistant which makes it desirable for severely
corrosive environments. Life cycle costs of tray installations can be dramatically
reduced by the extended life expectancy of fiberglass.

Designing for Versatility

Of these systems, wire basket cable tray systems are the most versatile. Wire basket cable
tray systems are produced by welding a net, forming the channel, and finishing after
fabrication. All fittings for wire baskets can be easily formed from the straights in the field
with no special tools. The 2" x 4" formation of mesh permits continuous airflow to help
prevent heat buildup, and the open design prevents the buildup of dust, contaminants and
bacteria. The wire basket tray is produced in standard 10” lengths and supplied in three
channel depths: 2", 4", and 6”. The 2" load depth tray has nominal fill widths ranging from
2" to 24" wide, the 4" load depth has nominal fill widths of 4" to 24" wide, and the 6" load
depth tray has fill widths ranging from 6" to 24" wide.

12 Insights Magazine | November/December 2021 | www.ieci.org