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#78786 - 10/24/01 06:19 AM NEC Question on Electrician's Examination
Joe Tedesco Offline
Member
Registered: 10/07/00
Posts: 2749
Loc: Boston, Massachusetts USA
Here's a question that was on an electrician's test. The student answered (d) as the correct one. He was told he was incorrect?

What is the correct answer?

Note: See 110-5, and that no insulation, or conductor material was given?

Question No. 9: Which of the following statements about the general requirements for number 6 conductors is true?

(a) It is required to be terminated at 75 degree C ampacity.

(b) It is required to be terminated at 60 degree C ampacity.

(c) It must have insulation rated 60 degree C ampacity.

(d) It must have insulation rated 75 degree C ampacity.

I will invite the student to join this board so he can add more on this subject.
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#78787 - 10/24/01 09:25 AM Re: NEC Question on Electrician's Examination
TWM1 Offline
Junior Member
Registered: 09/21/01
Posts: 3
Loc: Ft Hood, Texas, US
The general rule would apply and the only possible answer with what is given is that it needs to be terminated at 60 degrees.
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#78788 - 10/24/01 11:36 AM Re: NEC Question on Electrician's Examination
George Corron Offline
Member
Registered: 05/16/01
Posts: 717
Loc: Lorton, Va USA
I tend to agree, with no further info I would have to apply 110-14 C and assume (dangerous, huh ? especially on a test) that it would be terminated in unknown terminations, which would mean you have to assume under 100 amps and terminate it at it's 60 deg. C ampacity. If that was the wording with no further explanation, it was broad based, KINDA vague.
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#78789 - 10/24/01 01:04 PM Re: NEC Question on Electrician's Examination
Scott35 Offline

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Registered: 10/19/00
Posts: 2707
Loc: Anaheim, CA. USA
I tend to agree with the other two posts.

Since there is no Insulation type given, this could be anything from TW [60 degree C], to THHN [90 degree C].

Since we can use Conductors with THHN Insulation and rate them at 60 degrees C for wet locations, or 90 degrees C for dry locations [for ampacity adjustments], this would exclude (c) and (d).

Since we are to use the 60 degree ampacity column in 310-16 for conductors sized #14 through #1, this would eliminate (a).

By default, the only remaining answer would be (b).

Scott SET
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#78790 - 10/24/01 03:40 PM Re: NEC Question on Electrician's Examination
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Joe,

I think it's a poorly worded question and could be viewed different ways.

I think that it would be (b) or (c) depending on what they were looking for.
I would lean torward (c) with 60C as a Minimum rating.

Question:

Is 75C wiring also rated 60C ?


Bill
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#78791 - 10/25/01 05:21 AM Re: NEC Question on Electrician's Examination
Joe Tedesco Offline
Member
Registered: 10/07/00
Posts: 2749
Loc: Boston, Massachusetts USA
Bill:

I agree that the question may be poorly worded. Seems like we all agree on the correct answer.
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#78792 - 10/25/01 05:54 AM Re: NEC Question on Electrician's Examination
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Joe,

I'm not sure which answer we're all agreeing on. I see (b)s and my (c)answer. (Or, do you mean that we all agree it is poorly worded)

Does the NEC consider a 75C conductor as also being rated 60C ? like dual-rated?

Bill
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#78793 - 10/25/01 08:24 AM Re: NEC Question on Electrician's Examination
Redsy Offline
Member
Registered: 03/28/01
Posts: 2056
Loc: Bucks County PA
Bill,
I understand that the temp. rating is the MAXIMUM temp. that the insulation can withstand without beginning to physically degrade. Therefore, if it is rated for 75 deg., any temp below is acceptable.
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#78794 - 10/25/01 02:29 PM Re: NEC Question on Electrician's Examination
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Redsy,

Yes, I understand. I was just wondering if that would be proper terminology to state that 75C wire is also rated 60C. I'm just asking for the purposes of this test Question but I guess that it doesn't really matter.

Joe,

You didn't tell us what was considered to be the correct answer??

Bill
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#78795 - 11/02/01 07:40 AM Re: NEC Question on Electrician's Examination
atran Offline
Junior Member
Registered: 11/02/01
Posts: 1
Loc: Cudahy,WI,53110
Bill,
The answer is "C" !!!
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