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#81872 - 09/27/02 10:28 AM 100A Commercial Service  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
Can I use the 90ºC column if I'm using RHW-2/USE-2 for a commercial service? If so, then 100A Commercial service may use #2 Al RHW-2 Conductors?

My AHJ thinks so, but I thought we were limited to the 75ºC Column for services?

(Do to terminal temp ratings?)

[Linked Image]

(Still not gonna use the Mission Impossible guy yet... Just call me chicken!)


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

2017 / 2014 NEC & Related Books and Study Guides

#81873 - 09/27/02 11:25 AM Re: 100A Commercial Service  
Ron  Offline
Member
Joined: Mar 2002
Posts: 582
White Plains, NY
There is no equipment that is listed with the use of 90 deg terminations. Granted there might be lugs in the equipment with a 90 listing, but the equipment is not listed with lug rated 90 deg, just 75 deg.
So, you are right, you need to use the 75 deg column at most. At 100A and below, if you don't know the equip lug temp, you need to use the 60 deg column by default.


Ron

#81874 - 09/27/02 05:19 PM Re: 100A Commercial Service  
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
Virgil,

Where do you find these guys?

This subject is covered several times in the study guides for the inspectors test. Is this guy still on probation?

Lead this inspector by the nose to 110.14(C)(1)(a)(3) & if he can't understand that, then shown him the commentary in the handbook that follows that article.

But then again, as W.C. Fields said "Never smarten up a chump." [Linked Image]

Tom


Few things are harder to put up with than the annoyance of a good example.

#81875 - 09/28/02 12:09 AM Re: 100A Commercial Service  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
Tom, this is the sad part...

The particular AHJ in question is actually the best choice of the four available as far as code knowledge.

The first AHJ I have used doesn't do it anymore... He was "too nice a guy" in my opinion... Not AHJ material at all. He was the one that always irked me by tightening all of my terminations.

The second AHJ I used, I have only called once, and that was in Hinton, WV. He was OK, and gave a decent inspection, but lives too far away for regular use.

The third AHJ I've used is the one that uses shallow metal boxes and complains of them shorting out when powered up... However, he's the only AHJ to ever actually quote code... he quoted 250.66 to let me know that I could've used #6 instead of #4 for the GEC... He's also the one that says torqued lugs will just loosen up anyway...

Then, there's the one in question, he's been pretty good and the only one with the General rating as well as the One and Two Family Dwelling Rating...(the one that broke a meter lug once, and now doesn't "check torque" anymore) but he did baffle me on the phone this morning when he said that #2 Al woud be OK for a 100A commercial service (Construction Trailer). That's when I decided I better ask y'all... (I analyze things to the nth degree, apparently...)

What size Al and Cu should be used?

#1 Cu THWN? (60ºC Column)

#1/0 Al RHW-2? (60ºC Column)

And if the Disco and Meterbase have a labelling saying 75ºC, then:

#3 Cu THWN?

#1 Al RHW-2?

As unsure as I am of myself, I'm the most code knowledgable sparky in Greenbrier County (That I know of). It's really that sad, I'm not bragging, I'm complaining!

[This message has been edited by sparky66wv (edited 09-28-2002).]


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

#81876 - 09/28/02 06:58 AM Re: 100A Commercial Service  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,303
assuming the meter is 75c compliant go to 310.16 by way of 110.14.....

Quote
(b) Termination provisions of equipment for circuits rated over 100 amperes, or marked for conductors larger than 1 AWG, shall be used only for one of the following:
(1) Conductors rated 75°C (167°F)
(2) Conductors with higher temperature ratings, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity of the conductor size used, or up to their ampacity if the equipment is listed and identified for use with such conductors


but note the #1 minimum...( so #3 is out..)


#81877 - 09/29/02 03:09 AM Re: 100A Commercial Service  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
Thanks, Steve...

*embarrassed*

I guess I've never done a 100A Commercial Service Before... All half dozen or so I've done as Kelly Electric have all been 120/240V 200A... I've hashed out that 3/0 Cu THWN in 2" Pipe was the cheapest way to go there many moons ago...

Thanks for walking me through it, guys...

Someday I might even tackle conduit fill (using different sized conductors and without referring to Ugly's...)!

Keep in mind, I've never failed an inspection!

*awaits boos, hisses, and thrown tomatoes...*

[Linked Image]

#1 Cu THWN would be the "cure all" size, then...(?)



[This message has been edited by sparky66wv (edited 09-29-2002).]


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

#81878 - 09/29/02 08:10 AM Re: 100A Commercial Service  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,303
Quote
#1 Cu THWN would be the "cure all" size, then...(?)


i suppose so...(unless other posters object?)

yeah 3/0 cu...did a 200A commercial service in pipe a while back , couldn't seem to find 4/0 CU SEU.....i don't think pipe is prerequisite ???

Quote
Keep in mind, I've never failed an inspection!


well you've got to BE inspected first....

IS THERE AN INSPECTOR IN THE HOUSE?


I've never been failed...
Never seen a 'red tag'
Don't know what a written 'violation' is..

i suspect Virgil & I are leading a sheltered carear ...
[Linked Image]

If in fact, an AHJ is willing* to send one of these items i would gladly pay for it, & your postage.

~ I will frame it for my office.....

*(please PM me if so....)


#81879 - 09/29/02 10:18 AM Re: 100A Commercial Service  
Tom  Offline
Member
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
Glad to oblige, though our stickers are really simple.

Tom


Few things are harder to put up with than the annoyance of a good example.

#81880 - 09/29/02 01:35 PM Re: 100A Commercial Service  
sparky66wv  Offline
Member
Joined: Nov 2000
Posts: 2,236
West Virginia
No, pipe is not required, but the only SE cable my supplier has is #2 Al SEU and SER and 4/0 Al SEU and SER. Any other size and it has to be THWN or RHW-2 in Pipe. (Don't like SE Cable anyway...)

I've had better than a dozen or so inspections (I'm sure some of you have that many a week!). Usually I can point out more violations than they can... [Linked Image]

I wish that the inspections were for all phases of work rather than just services.

I wonder if I could pass a rough-in inspection...?!?!?!

[This message has been edited by sparky66wv (edited 09-29-2002).]


-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

#81881 - 09/29/02 02:44 PM Re: 100A Commercial Service  
txsparky  Offline
Member
Joined: May 2001
Posts: 552
Magnolia,.Texas U.S.A.
66
I dont think that with your attention to detail,that you would have any trouble passing an inspection.From your posts,I believe you must read the code book cover to cover for every project you undertake to see what and what does not apply to it.(and then you start a thread to be sure you didn't miss anything [Linked Image]) Wish I could say I've never failed an inspection.


Donnie


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