Rules for Importing a DXF CAD File

The rules of drawing grids in AutoCAD include:

• Earthing system drawing should be saved as an ASCII DXF file.

• Set the measurement units of the CAD drawing to be in Meters, Centimetres, Millimetres, Inches, or Feet.

• Draw the grid using only Lines, Polylines, LWPolylines, Circles, or Arcs entities.

• Circles and Arcs will be converted to Lines when imported.

• Lines snap connected otherwise an undesired current discontinuity will occur.

• If drawn in 3D, the Positive (+’ve) Z coordinate signifies depth, and the negative (-’ve) Z coordinate signifies above-ground.

Below is an image from AutoCAD of an above and below-ground earthing system. When drawn in 3D CAD it appears to be upside down because negative Z is for the above-ground earthing conductors.