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?)



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

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.

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."

Tom

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).]

assuming the meter is 75c compliant go to 310.16 by way of 110.14.....


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

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...*



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



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

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 ???


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 ...


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....)

Glad to oblige, though our stickers are really simple.

Tom

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...

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).]

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 ) Wish I could say I've never failed an inspection.