ECN Forum Forums Code Related Discussion NEC & other Code issues 200 Ampere Wire in Commercial Work

OK... Got caught up in a job for a Veterinary Office/Kennel. I've been a good sparky and have went with PVC FS boxes and WP covers to protect from washdowns.

Time comes for the service, and it really could get away with 100A (gas heated building) but I figured for 200 for upgradability...

Using the only available conductors from my supplier for a 200A service, I ran 2" PVC from the disco to the panel, and installed the 4/0 Tri rated "new stuff" that's really easy to work with.

Several things suddenly came to a really bad light...

The neutral is 2/0...

Table 310.15(b)(6) is for dwellings only!

My 2" pipe is too small for 3 250KCm conductors and a #2 Ground...

GE brand 150 Ampere Mains are rare as hens teeth.

I asked my AHJ what to do and he said:

"You mean to tell me that 4/0 is big enough for 200A in a home, but not in a business?"

I was dumbfounded...

He suggested that I was "reading too deep into the code."

Hunh?

You can't use 3/0 or 4/0 cu? I would think either of those would be available at your supply house. Were you originally running 4/0 Al URD and a #2 through the PVC? Our supply house has been stocking 4/0 Al URD quad(4/0,4/0,4/0 & #2)which can come in handy for residential when using a disco.
I don't know how far your run is but if I lived near by I'd make you a deal on some 4/0 cu. I've got about 21 pcs. 65' long left over from a 330' pull I did last year that I'm still trying to forget.

Tri Rated Cable, (RHW-2, XLP, USE-2) with 2 4/0's, a 2/0 Neutral (with requisite white stripe) and a #4 Ground (green) all Aluminum and twisted into a single cable. There are three LB's and a Sweep in this pull, and I'm a solo act, so pulling THHN Cu conductors would be a BIG challenge. (It was hard enough pulling the tri-rated cable...)

I guess the sad point to this is I don't have to change it... The AHJ will pass it as is, and doesn't understand why it shouldn't...

I guess an AHJ around here has to be real lenient...

Virgil,

FYI, The PoCo around here only uses 1/0 Alum underground to Meterpan for a 200A service.

Bill

per C-10, 4-THHN 3/0's CU's will fit in 2" sch 40,(so less with reduced noodle & ground) 310-16 @ 75 deg, meets 110-14(c)(10(b) , which i'd only do if called on this, with a gallon of 77 to boot....

I'm confused...

So... 310.15(b)(6) can be used for commercial if the PoCo has undersized their conductors? Where does it say that?

I'm so lost...

Cu Thhn is out of the question... Did I mention 3 LB's?
Maybe my technique is bad, but I can't pull 3/0 Cu Thhn through the bend of an LB in sub-freezing weather without some major help... Three strong men and a hammer... (poor conductors)

I guess I'm just lazy...



It's all moot, they'll pass it anyway, and I'll be thought a fool by everyone I work with if I change it...

That "inspector's" response is simply amazing. How big are the LB's? Mogul sized I hope. Are the covers for the LB's spaced out 4" (required distance per 314.28(a)(2)exc.)

Elzappr;
Have you priced out moguls lately? or asked for a lead time?

Moguls? Dunno... I doubt it...

4"? What, from the hole in back to the cover?

I doubt there's 4"...

Boy, I've opened a can of worms...

Heh... I'd like to see some of you guys do business here... You'd get one job (if it's T&M, you'd never get a bid job unless you're willing to bid a price lower than just the materials cost...) and then it would be over... "He's too expensive and too hung up on code" would be your reputation... don't mean to sound bitter, but I've had a long rough year,

What I've learned?

Complete "to the letter" code compliance = starvation

A pretty simple equation really...

Exactly! Thats why we have to find a way to clean up our own act. I don't know the answer tho. I got virtually no reaction to my earlier question about legal liabilities for under-compliant installations. I was hoping that SOMEONE would be familiar with the topic and reinforce the notion, that I think is brooding throughout the country, for holding electricians accountable for their "make-do" pragmatic methods. I'm just trying to look ahead, so that what I do today doesn't come around and bite me 15 years from now!
Inspectors look at the closed boxes and make sure there are no openings for the fire to blow out of, but its up to us to not make those loose connections, or to not hammer those conductors into the LB's.

[This message has been edited by Elzappr (edited 01-06-2002).]