Cable Tray Support Requirements

Load and support requirements.

Cable tray support requirements.

Mushroom headed steel roofing bolts and nuts shall be used for the installation and coupling of trays. Because cable trays offer flexibility for expansion and changes engineers and designers should design and size cable tray systems to anticipate both current and future needs. Do not use a cable tray as a walkway ladder or support for people. Standard depths of 1 1 inches in metal systems and 1 1 1 8 1 5 and 2 3 16 inches in nonmetallic systems.

An economical support for cable drops and branch cable runs from the backbone cable tray system. Nema fg 1 was rescinded as a published standard in november 2017. Hazardous voltages in electrical equipment can cause severe personal injury or death. In a closed system such as raceway wireway or solid bottom tray with solid covers plenum cable is not required by the nec.

Plenum cable can be used only in environmental air handling areas. Cable tray is a mechanical support system for cables and raceways. 29 cfr 1910 303 b 8 requires the appropriate mounting and cooling of electrical equipment. Be strong and rigid they need to be able to support all of the wiring they re going to contain have smooth edges burrs sharp edges and other projections can damage cable jackets and insulation be protected from corrosion hot dip galvanization or powder coating is must.

Cable trays shall be supported by mild steel galvanized brackets at regular intervals of 1 2mm maximum and at 255mm from bends and tees. Using cable trays as walkways can cause personal injury and also damage cable tray and installed cables. If used in these areas it must be supported in an open cable support system such as cable runway center rail and ladder type cable tray.