Cable Trays – Types, Construction, and Uses

The use of cable trays is fairly widespread in countries outside the US.
 However, cable trays are gaining ground here as well. The offset of 
installation costs to the often more expensive approve cable is one 
reason. The ease with which reconfiguration of machinery and equipment 
is another. AFC Cable Systems

Steve Maurer, IME

The use of cable trays is fairly widespread in countries outside the US. However, cable trays are gaining ground here as well. The offset of installation costs to the often more expensive approve cable is one reason. The ease with which reconfiguration of machinery and equipment is another.

There are several types of cable trays:

  • The ladder tray, so called because it looks like an extension ladder section.
  • The solid bottom tray formed with sides to secure cabling.
  • Trough cable tray, with supports every four inches.
  • Channel cable tray, similar to the trough, but narrower.
  • The wire mesh tray, often used beneath the floors of data centers to wrangle low-voltage, telecom, and fiber optic cables.
Sometimes the solid bottom tray is specified with a cover, although that's unnecessary for code compliance.

The ladder tray's construction allows the maximum flow of air around the conductor cables, minimizing heat buildup. It also makes dropping conduit or cables to machine or equipment locations easier.

Because of solid construction, many of the other types of trays may need ventilation holes cut into them, particularly if they're covered. Add to that the potential buildup of dust, dirt and moisture, and it's easy to see why ladder trays are used more frequently.

All cable trays are made of corrosion-resistant materials, such as galvanized steel, stainless steel and, in some cases, a plastic coated covering. Many cable trays are also constructed of aluminum.

Cable trays can be used in a variety of installations. For example:

  • Power distribution cabling
  • Control wiring where additional shielding is needed
  • Telecommunication and datacomm cabling
  • Fiber optics
When used for high voltage or power distribution, the conductors must be encased in an approved conduit. Not all flex conduit is permissible. Check with your supplier or cabling manufacturer to make sure you're using the correct conduit.

I'm still a diehard conduit bending junkie. But, I'm finding more compelling instance where cable trays provide a more efficient and cost effective option.

Not to mention saving wear and tear on the old back and arms for installing or pulling wires and cables!


Photo courtesy of AFC Cable Systems

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