Cross Sections

A Cross Section is a to-scale drawing of what you would see if you cut through a bundle, wire or cable: every conductor with its insulation, packed as tightly as they will go, with the estimated overall diameter. Use it to size coverings, grommets and clips, and to check how full a bundle is.

Cross sections appear in two places:

• On the Layout view, for the selected Bundle. See Bundle Cross Sections.
• In the details of a Wire Part or Cable Part. See Wire and Cable Part Cross Sections.

Diameters are shown after the diameter sign, in mm when the harness’s default length unit is metric and in when it is imperial (set under Main Menu → Harness settings).

Bundle Cross Sections

Select a single bundle on the Layout view. Its cross section appears in a card in the bottom left corner of the view, in place of the Selection Information row.

The card shows:

• The bundle’s ID and its estimated overall diameter.
• The cross section, drawn to scale, inside a dashed circle marking the outside of the bundle. A thin bundle is drawn small and a thick one fills the card.
• The number of wires and cables in the bundle.
• An info icon: hover it for how the diameter was worked out.

Each wire is drawn in its insulation colour, with a band in its stripe colour, around its copper conductor. A cable is drawn in its jacket colour, with its shield (when it is shielded) and its cores inside.

To hide the card, select Hide cross section in its top right corner. While it is hidden, a Show bundle cross section button appears in the bottom left corner whenever a bundle is selected; select it to bring the card back. Your choice is remembered and applies to every harness.

What Is in a Bundle

The cross section includes every wire and cable routed through the bundle:

• A Cable whose cores all pass through the bundle is drawn whole, in its jacket.
• When only some of a cable’s cores pass through, the cable has already broken out, so those cores are drawn as loose wires.
• Twisted Wires, and twisted cores inside a cable, are packed together as a group.

The diameter is of the wires and cables only; it does not include the bundle’s coverings.

A bundle with no wires routed through it shows No wires are routed through this bundle.

Selecting Wires from the Cross Section

left-click a wire, cable or cable core in the cross section to select it. Hold shift or ctrl/cmd while you left-click to add to the selection. Selected items get a bright ring around them, and items that are not highlighted are dimmed.

The card stays on the bundle while you pick from it: the bundle is highlighted rather than selected, and the Selection Information row for the new selection appears beside the card. left-click the background of the drawing to select the bundle again.

Once you select something else on the canvas or elsewhere in the app, the card goes back to following the selection: it shows the cross section of a newly selected bundle and closes for anything else. It also closes if the bundle is deleted.

Wire and Cable Part Cross Sections

Open a wire or cable part’s details, in the Parts view, a part library or the Parts Catalog, to see its cross section below the part image, with its overall diameter.

• A Wire Part needs a Gauge to be drawn.
• A Cable Part is always drawn. If any of its cores has no gauge, the diameter is marked (estimated).

How Diameters Are Estimated

Every size is worked out from the parts assigned to the wires and cables, and anything a part leaves unset is estimated:

• Conductor - From the Gauge, as a stranded conductor, which is about 12% wider than a solid one of the same cross-sectional area.
• Insulation - A typical thin-wall thickness for the conductor size (as ISO 6722 thin wall or SAE TXL automotive wire) up to 6 mm², and thicker walls above that.
• Shield - A shielded cable gets a 0.25 mm layer for its braid or foil and drain.
• Jacket - Thin on small signal cables, growing with the size of the cores inside, between 0.5 mm and 3 mm.
• Packing - The wires and cables (or a cable’s cores) are packed as tightly as possible. Twisted wires and twisted cores are packed as a group first.

A wire or core with no gauge, because it has no part or its part has no gauge, is sized as 0.5 mm² (about 20 AWG, shown in the harness’s gauge unit). It is drawn with a dashed outline, and the bundle card shows Estimated next to its info icon.

Entering Your Own Sizes

The estimates are typical values; real wire varies by specification. When you know the datasheet figures, enter them in the part’s details:

• Wire Part - Insulation (the insulation thickness). The overall Diameter is then calculated from the gauge and insulation.
• Cable Part - Jacket (the jacket thickness), Diameter (the overall diameter) and each core’s Insulation.
• Covering Parts - Thickness (the wall thickness).

While a field is empty, its estimate is shown in grey as the placeholder. A plain number is read in mm (or in when the harness’s default length unit is imperial); you can also type a unit, such as 0.4 mm or 0.016 in. Clear the field to go back to the estimate.

A cable’s Diameter replaces the calculated one. If it is smaller than the packed cores, they are drawn shrunk to fit inside the jacket; if it is larger, the extra space is filled.

Drawing Bundles at Their Estimated Thickness

The same estimated diameters size the bundles on the Layout view. With Draw bundles at their estimated thickness enabled under Main Menu → Harness settings → Layout → Bundles (on by default), each bundle is drawn as wide as its cross section, plus the wall of each covering on it, so thick bundles stand out at a glance. See Bundle Appearance.

When a covering part has no Thickness set, its wall is estimated from its type: