This has been beat to death in Mike Holt's BB and the DIY BB, but I'm still confused.

My supplier only carries #4/0 and #2 Al SE and SER cables... no other sizes. I realize that the supplier is not infallible...

Bidding around here is hard enough, I can't compete with the ignorant! Just what the heck am I supposed to do with 100A Sub panels? #3 CU THHN in pipe? #3-3 w/G Cu NMB cable (which is unavailable here)? The supplier is clueless, I just called him...

I've been through about $10K of lost bids this week mainly due to sticker shock...

Any venture capitalists out there? I promise not to spend frivolously like the tech companies did...

If not...Anybody wanna buy a slightly used Electrical Business? Just Kidding folks...




[This message has been edited by sparky66wv (edited 05-16-2001).]

What wiring methods have you used in the past to install subpanels? You could order what you want to use and keep it in shop stock.

Oh... This is in reference to Table 310-15(b)(6),

100A feed through discos are unavailable here, we generally use load centers for discos (raintite). Does the feeder from the first load center (being used as a disco) to the second (being used as the main panel) qualify as a service feeder, or is it a sub feed??

BTW the EI passed a similar install just a few weeks ago... It was fed from a 200A panel with #2 SER (most around here would have used SE) and was obviously a sub panel.

Would using a main breaker in the sub panel instead of a MLO make any difference in the definition of the intended use of the cable?

This code loop could triple the price of a sub panel install for me and put me out of the competition, I can't be the only one complying with codes that "no one has heard of" around here... and expect to make money, or even get the jobs in the first place!

There appears to be some controversy on whether or not #2 SER is allowed in a sub feed... Sorry I didn't make that part clear...
http://www.mikeholt.com/forum/Forum1/HTML/000545.html
http://forum.doityourself.com/showthread.php?threadid=58652



[This message has been edited by sparky66wv (edited 05-16-2001).]

oh boy,
here we go...someone call for more tankers...

personally, i'm confused as to which code overrides which, and what changes have taken place ( or are going to..)

some articles to consider;
T310-15(b)(6) and whatever the 99' change was
338-4(a) brings you to;
336 A&B ends up in
336-26 , note the 60 deg deal...
110-14(c) honorable mention.....
T-310-16 why not....

Whoa... looks like that leaves us with a #1/0 Al Sub Feeder for 100A...

Steve or Bill... you got the ROP's on this?



[This message has been edited by sparky66wv (edited 05-16-2001).]

it would be at;
http://www.nfpa.org/Codes/National_Electrical_CodeR_NEC/Proposals/necpdf/A280-310.PDF

go down to about pg 65 ( Adobe Acrobat file)

points of interest;
Log 3908(accept) - to exempt 336-26 in T310-15(b)(6)
Log4200(reject) substantiation states;
[ "99' wording schizophrenic" ]
i sense the CMP's intent here, and a little frustration.....
Log 2895(reject) looks like a table for ampacity?>>>....

Just what the heck am I supposed to do with 100A Sub panels? #3 CU THHN in pipe?


That's what we typically do. MLO sub-panel unless the sub is in a separate building.

I don't follow the other concerns, questions that lead to the 1/0 AL. We don't use AL for sub panels unless we are going underground.

GJ


[This message has been edited by golf junkie (edited 05-16-2001).]

GJ;
the article in question is not entirely clear as to where #2 for 100A ,4/0 for 200A can be run in a dwelling.

the code had a 99' change, and is apparently going to have a change or two in 02'.

I'm confused on what has changed and why...

Another point, probably only a WV thing, but how am I supposed to pipe in and use 3 #3 THHN copper for the feeders AND a reduced ground and compete with those using only a #2 Al SE (NOT SER)?!??! Please realize that there is a major cost difference here...And please find me a loophole! (I'll use SER though...)

BTW I've lost 3 of 3 bids the past week, 2 due to "unfair" competition like I mentioned above... the third due to "Sticker shock"...
I don't mind it so bad when I actually bid against electricians...

Virgil;
it's simply a matter of wording. don't go looking for #3 just yet, those other threads
,burning a hole thru cyberspace, have some big guns who are explaining the situation down to the punctuation marks.
(As well as some ROP's)

I'm presently doing an 8 meter pack 120/240 1 ph 3 wire, instead of 3 ph to take advantage of #2, on an 8-unit dwelling.....
( wanna job ?)

Yeah, but have we actually come to any conclusions? All I hear are code loops, man...



[This message has been edited by sparky66wv (edited 05-18-2001).]

Sparky66
I think the only conclusion that would be valid is from your local AHJ or if someone requests a formal interpretation from the NFPA. Anything else is just opinion.
Don(resqcapt19)

The AHJ is my own conscience...

Unless a meter gets pulled (EI visit for the service only)

or I'm in L'burg (building inspector- don't get me started again!)

Article 215-2(d)permits using article 310-15(b)(6) for sizing the feeder conductors in an individual dwelling unit. Article 310-15(b)(6) directs you to table 310-15(b)(6). Table 310-15(b)(6) doesn't mention SER insulation type. What is SER? Service entrance rated?

I don't know what it means, but SE is flat with 2 hots and a bare neutral (wrapped around the hots). SER has two hots, an insulated neutral and a reduced ground, and is round in shape, and the conductors are twisted together. Does R stand for "round" (that's how I remember it)

[This message has been edited by sparky66wv (edited 05-18-2001).]

215-2(d) is all well and good, but what if you're subbing off of a 200A panel?

215-2(d) applies if you have a #2 service entrance conductors, but most situations I'm talking about are truly sub panels being fed from a 200A Panel, although I started this thread with a 100A service and disco in mind. How does this change things here?

Someone somewhere mentioned using a 90A breaker and saying to heck with it...

You size your service-entrance conductors per Table 310-15(b)(6). Why can't you size the 100 amp sub panel feeder conductors per Table 310-15(b)(6)? Me thinks some people are reading way too much into this example. Present company excluded! Like Don said, talk to the AHJ. IHMO the NEC Gods need to tie article 215-2(d) directly to Table 310-15(b)(6) and not article 310-15(b)(6). That would eliminate some, if not all, of the confusion. If it was me installing a sub panel, I would use Table 310-15(b)(6).

336-26 needs a ref to 310-15(b)(6) the same as 215-2(d) does ( as one ROP intends)

This thread has now been introduced to the big guns at the IAEI Bulletin Board . It looks like it's heating up there too! Let's see, that's four independent BB's on one unique topic at the same time! Wow! And coming to the same confusions I might add...