A year after this post started (2004) I used AutoCAD and 3D solids to coordinate a Central Plant Electrical Power, 27 bus duct runs and only one part needed to be reordered. We were the only trade to do so in 3D. Today every trade has excellent tools in AutoCAD MEP Except electrical! No Busduct No Conduit. Nothing! Sorry it has conduit but not really correct conduit. Try to prefab off the conduit catalog and it all goes to hell. No correct bending radius or even OD sizes.
Autodesk Time to make this happen. Or at least buy into G.E.'s Autobus solution!
If you want to draw correct busduct there is a tool called Autobus buy G.E.. Everything you ever wanted. Works inside AutoCAD 2000.
Otherwise use the hvac tool for duct. Rectangular duct, size per your spec. and use 90 elbows and 45 elbows and you can limp through with minimal problems.
I must create some major busduct drawings and have tried almost everything.
Becoming desperate I tried it with Autobus 2005.
I'm constantly receive an "error" message: Autocad message :file problem after I installed Autobus2005
as well: Invalid application name in 1001 groupBad mod status=-5003
This is all critical for my firm as well. Conduit was not properly implemented. It was just a cheap translation of pipes. There is no bus duct or ductbank capability. You can't route groups/arrays of conduits together (i.e. you have to individually manage every conduit). Conduits don't have any integrated contents/wire properties. Rise/drops are a nightmare, and have been greatly overcomplicated in MEP. I don't even want to get into display problems with MEP objects in general.
It's all known stuff, but is ignored by Autodesk in favor of new features that can look appealing in a brochure (regardless of how well they function).