Revit Tip – Modelling Heavy Duty Cables or Wires using Conduits

by Dennis Collin

When working with electrical infrastructure models there is a frequent need to show the positioning of heavy-duty cables on site. Revit lacks such objects although there are wires, they are 2D in nature and do not show in 3D and are not quite appropriate to use in an infrastructure model.

Previously I posted on the usage of Adaptive Components and Flexi Pipe/Duct to represent such elements, however both of those options are limited as they do not address the problem of minimum bend radius for cables. Cables obviously can only bend so much before the cable is damaged. As a rule, the bending radius is normally expressed as a factor of the overall dimension of the cable for example, 6 times the outer diameter of the cable.

Fig 1. Modelling conduit as cable provides an adequate work around!

The bending radius is therefore driven by the cable size and can be easily addressed by using a look-up table in a suitable bend family. The best candidate to do this is the conduit system family. It is electrical in nature and has a size list which can be set within the Revit project template.

Fig 2. Setting a size list for a modified conduit family that will serve as cabling.

Once the custom size list is defined, duplicate a conduit system family and populate the parameter data and fitting families to make it easily identifiable from regular conduit with the use of view filters. Type comments describing it as cabling is a start!

Fig 3. Configuring the cable bend, look-up table to reflect the cables minimum bend radius!

For the cable bends, I used a conduit fitting elbow family renamed and reconfigured to serve as a cable bend. To ensure the resultant geometry and family adjusts correctly, a look-up table is assigned to ensure that the cable component does not exceed the minimum radius that is defined by the cable diameter.

A look-up table is just a CSV type file where the various cable sizes are listed, along with appropriate diameter, bend radius and other values that will be push to the fitting.

Fig 4. Customising the Conduit system family to reflect cabling.

To make the conduit size to reflect the actual cable size, edit the ‘cable’s’ type properties and select the custom size list described earlier. Appropriate cable bends and fittings can also be specified as required. Like other Revit families the cabling can be filtered and coloured and scheduled showing built-in or shared parameters as needed.

Fig 5. A conduit schedule but used to represent cabling!

Creating families, parameters and work-around solutions are some of the topics covered on our Revit content training courses. Visit the Arkance UK site to get an overview of the courses on offer and talk to one of the team for dates and availability or if you have more bespoke requirements, just ask, we are here to help!

Fig 5. Use Revit’s View Filter function to highlight and isolate cables from other categories!