Wiring length,Voltage Drop, Riser diagram?

[ekulenica]

Does any one knows how to get the wiring length on a tag?
MEP 2008 calculates the voltage drop of the circuit, and it does display the length of circuit, but the moment I change the location of one of the receptacles in the circuit, the length of that circuit doesn't change, and thus the voltage drop.
How is Revit MEP 2008 calculating the length of the circuit?
Is the home run of a circuit running up the wall into the ceiling and straight to the panelboard (taking the shortest path), or it goes up to ceiling and than runs from the corners of the rooms till it gets to the panel board?
It is smart enough so the wiring goes around doors, and thus automatically recalculating the length of the circuit?
Also since Revit is able to calculate the length of the circuit, can it be able to draw a riser diagram? How is the riser diagram created in Revit MEP 2008? Is the riser created the same as in AutoCad or can Revit MEP 2008 draw the riser based on the data collected on the drawing? That is, length of wires, panelboards' number and locations.

Thanks,

[mjdanowski]

Does any one knows how to get the wiring length on a tag?
MEP 2008 calculates the voltage drop of the circuit, and it does display the length of circuit, but the moment I change the location of one of the receptacles in the circuit, the length of that circuit doesn't change, and thus the voltage drop.
How is Revit MEP 2008 calculating the length of the circuit?
Is the home run of a circuit running up the wall into the ceiling and straight to the panelboard (taking the shortest path), or it goes up to ceiling and than runs from the corners of the rooms till it gets to the panel board?
It is smart enough so the wiring goes around doors, and thus automatically recalculating the length of the circuit?
Also since Revit is able to calculate the length of the circuit, can it be able to draw a riser diagram? How is the riser diagram created in Revit MEP 2008? Is the riser created the same as in AutoCad or can Revit MEP 2008 draw the riser based on the data collected on the drawing? That is, length of wires, panelboards' number and locations.

Thanks,

Length should be a parameter under a "Electrical Circuit" category for tags.
I am not sure how it calculates length unfortunately.
Right now, riser diagrams are still confined to drafting views (though I am sure it is on horizon as many people have been asking for this)

[brad-TEC]

Are you changing the farthest component in your run when you are expecting a change in the circuit length?

I am currently "testing" Revit MEP for our A/M/E firm. Some of our Architects are currently using it on projects, but we are currently sticking to AutoCAD on the M/E side until we feel more comfortable with Revit. The reason I bring this up is that I was looking at how Revit does voltage drop this morning, and it seems somewhat different than how we currently calculate it.

From what I can tell, the distance used for the voltage drop calculation is the entire circuit length. We currently use the distance to the "center" of the load. So in a lighting circuit where we would normally specify #12, Revit is calling out #10.

I'm not sure this helps you any as far as how Revit calculates the distance. I will try to determine a path for several of circuits that I am currently working with to see if I can't come up with an answer to the question though. I wrote a pretty advanced voltage drop spreadsheet for our company, so voltage drop has a place in my heart. Now that Revit is automatically calculating it, and coming up with different answers than my spreadsheet, I have an urge to figure out how it is working.

[jwongmep]

Has anyone answered the questions posed here yet? How does RME calculate the wire lengths? Does it count the wire going down to the receptacles? Does it go around doors?