Open AutoCAD and start a new 3D drawing.

Set up layers for building, lightning rods, and rolling sphere.

Create the 3D model of the building using AutoCAD's modeling tools.

Add lightning rods at the highest point of the structure.

Determine the rolling sphere's radius based on guidelines or standards.

Create a 3D solid object representing the rolling sphere.

Position the rolling sphere above the structure, centered on the lightning rods.

Assign visual properties (color, transparency, linetype) to differentiate objects.

Review and refine the drawing as needed.

Save the drawing and share or use it as required.

1.

To create the protective zone using the rolling sphere method in AutoCAD, you can follow these general steps:

Import the CAD drawing: Open AutoCAD and import your building drawing by using the "Import" or "Open" command. Make sure the drawing is properly scaled and aligned.

Define the rolling sphere: Determine the radius of the rolling sphere based on the lightning protection standards or guidelines applicable to your project. Draw a circle with the desired radius around the building. You can use the "Circle" command or create it as a polyline with a specific radius.

Create the protective zone: The protective zone is typically a 45° cone-shaped area above the rolling sphere. To create it, follow these steps:

a. Draw a line from the center of the rolling sphere to a point on its circumference. Use the "Line" command and snap to the circle's center point and any point on its circumference.

b. Use the "Rotate" command to rotate the line by 45° around the center of the rolling sphere. Set the center point as the rotation base point and specify the rotation angle as 45°.

c. Copy and rotate the line two more times, each time rotating by 45° to create three lines in total. These lines should be evenly distributed around the circumference of the rolling sphere.

d. Close the protective zone by drawing lines connecting the endpoints of the three lines you created in the previous step.

3. (Cont..)

Assign the red color: Select all the entities that represent the protective zone (lines, polylines, etc.), and apply the desired red color to differentiate it from other elements in the drawing. You can use the "Properties" command to change the color.

Save and finalize: Save your AutoCAD drawing with the protective zone displayed. You can also consider adding a title, a legend, and any necessary annotations to make the drawing more informative.

4. (Cont..)

Remember that the rolling sphere method for lightning protection is just one approach, and it is important to consult the relevant standards and guidelines specific to your project. Additionally, it's always recommended to work with a professional electrical engineer or lightning protection specialist to ensure accurate calculations and design for lightning protection.