i have to use polylines to get the correct visuals, but i have to use simple lines for the intelligence that comes with autocad electrical.
I see, I don't know anything about AutoCAD Electrical... but got a chance to write this custom object, just for fun!
If you want to give a try, open AutoCAD 2007 or 2008 (I guess will work on there too) - and inside a new from scratch dwg....
1. Load the ARX
2. Set the LUNITS to architectural
3. Load the linetype "HIDDEN"
4. Call the command: MYMLINE
5. Select the start-end points
7. Change the LTSCALE to desired one.
Tell me if works.
Have fun.
Note: the ARX is a debug file.... I just made a quick coding.... the MYMLINE command will generate an object similar to the one you posted in the image...