Conduit / Conductor Calculator Tool - Review

What's wrong the electrician's ugly book with a little common sense?

There's nothing wrong with that book. It's actually a great book. I'm just trying to simply provide another simple supplemental tool; similar to many other calculations, analysis work, tasks, that are automated / simplified. I appreciate your feedback though.

Is the conduit fill rate compensated for length of conduit and number of cables being pulled through it? It should be. You can only do so much before the next cable gets stuck mid-pull.

The conduit itself is sized per the number of conductors inside (with conductor size / ratings used) when using the "(#1) Conduit Fill Calculator" calculator. Thus, from Chapter 9 Table 4 in the NEC:

• 2 Wires no more than 31% fill
• Over 2 Wires no more than 40% fill
• 1 Wire no more than 53% fill

As for the conduit length itself, we do not have a specific variable in place to address a cable getting stuck when the wire is pulled, in our algorithm. Assumption then would be for the user to include pull boxes themselves for pull points.

Example: Assume the (#1) Conduit Fill Calculator outputs that you need a 4" conduit for X conductors. The user can assume then, that every 250' let us say, a pull-box will be used, and a 4" conduit with X conductors between each pull point will be run.

Do you think that properly addresses your concern? Please let me know.

Sure. That is common sense way of looking at that issue, and I am sure more experienced field electricians know more about the limits than I do, and what to use to help with pulling, how far they can go, where to put pull boxes, etc.

Maybe you could provide an internal link in your calculator to a short discussion on topic?

The main thing is to comply with code for the basic calculations. We tried to capture the meat of the conductor and conduit sizing parameters the best we could. That said, it would be very difficult to account for every side case in the real world, but we're looking to improve the calculator as much as possible.

Great suggestion. We will add a note to that effect. The less confusions, the better. Thanks for the feedback.

The length of run will also depend heavily on the run itself (no. and tightness of bends, etc.) when determining the length that can be pulled without sticking. Very difficult, IMHO, for and automatic calculator to come up with a result; a lot of experience would have to be fed in somehow (maybe like an expert system, with as many man-years of experience as possible being used for the training). Otherwise, it's just a guess.

My comment would be have you or anyone working on this project/web site ever run cable in conduit?

This project might be considered an honorable challenge, but it may be unduly complicated by the variety of electrical codes around the world: NEC, BS, IS, IEC, our intrepid sponsor IEEE, etc.