Autosum function?

[bleeargh]

One of my clients is an electrical engineer. When he is designing his circuit panels he has to add up the amps of each individual circuit and make sure he specs out the correct amperage on his panel box. He was wondering if I could figure out a way for AutoCAD to automatically add up the individual circuit amps and give him an automatic total. Similar to the autosum function in the Microsoft Excel program. Is this possible?

[David Bethel]

It is possible to do but it would take a very specific set of rules and good bit of custom automation. -David

[bleeargh]

Thanks for the reply. When talking about "a very specific set of rules" and "custom automation" are we talking about writing specialized lisp routines and such? Could you be more specific?

[David Bethel]

Yes, that would be the approach that I would use.

If a block where created with attributes such a panel number, circuit number, amperage rating, voltage and phase, shunt trip breaker needs etc. and attached it to each circuit, you could go in add everything up for a specified panel. Along with total number of spaces required, total amperage, I guess you could even try to calclate the load balances and or make a panel schedule with the best case scenario. A pretty in depth project. -David

[CarlB]

It could be a fairly simple lisp routine if rather than "automatic", the user selects the text items to total, and selects the text to edit to show the total. I've heard that with 2006 you can use formulas in Fields, which could probably perform an "Autosum".

[bleeargh]

I have already created an attribute panel schedule. It's pretty much to the point of data entry. It prompts you for every aspect needed in the panel schedule. My knowledge ends when it comes to taking the information in an attribute and adding creative little functions to them, such as the afor mentioned sum function. Is there a online tutorial somewhere that gives an idea how to do this? Or am I resigned to digging out my useless AutoCAD manual? I appreciated the post CarB, however my client probably would prefer the autosum upon the data entry rather than the selection method. I neglected to say, I am using AutoCAD 2005, he is on 2004.

[David Bethel]

Adding a list of string values together is fairly easy:

(apply '+ (mapcar 'atof '("12.3" "33.3" "6.0")))

Should return 51.6

So if you can extract the attribute's string values into a list you can do it.

There would ba a lot of things check

• Panel name
• Phase leg
• Is the string all numeric characters
• Yada yada yada

For a 3 phase panel, you would to do this three times, single phase twice. -David