Representation of Tray-type Cable Trays

A tray-type cable tray can be represented in technical drawings using a combination of straight sections, side rails, cross members, bends, and supports, reflecting its structural layout and cable routing.

Basic Representation

Straight Sections: Draw the main horizontal or vertical runs as rectangular or trapezoidal shapes, depending on the tray type. Ladder trays are typically shown with two parallel side rails connected by evenly spaced cross members, while solid-bottom or perforated trays are represented as continuous rectangles with or without perforations. Cross Members or Rungs: For ladder-type trays, include transverse lines between the side rails to indicate rungs, usually spaced 150–300 mm apart.

Perforated trays can be represented with dotted or hatched patterns to indicate ventilation holes. Bends and Tees: Use angular lines or arcs to depict horizontal or vertical bends (30°, 45°, 90°) and T-junctions for branching runs. Vertical risers are shown as lines connecting different elevations.

Supports: Indicate supports such as trapeze hangers, wall brackets, or center-span supports with small symbols or annotations at regular intervals along the tray.

Covers and Hold-

Downs: If the tray has a cover, represent it as a parallel line above the tray base or with a dashed line to indicate a removable cover.

Additional Details

Cable Layout: Inside the tray, you can show cable bundles as parallel lines or shaded areas to indicate the number and type of cables. Dimensions: Include tray width, height, and rung spacing. Standard widths vary depending on cable load and project requirements.

Material and Type: Annotate the tray type (ladder, perforated, solid-bottom, wire mesh) and material (aluminum, galvanized steel, FRP) for clarity. Symbols and Notations: Use standard electrical or mechanical symbols for bends, reducers, and drop-outs to maintain consistency in engineering drawings.

Representation in CAD or Schematics

In CA

D software, use layers to separate tray structure, cables, and supports. Use line types (solid, dashed, dotted) to differentiate between tray base, covers, and cable bundles. Include labels for tray type, size, and cable specifications to ensure the drawing is informative for installation and maintenance.

By following these conventions, a tray-type cable tray can be clearly represented in technical drawings, ensuring accurate communication of its structure, routing, and installation requirements.