This NEC question is wrong?

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ivsenroute

ivsenroute

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What appears to be an easy question does not make sense when you find out the "correct" answer and explanation. Look it up then posts your answer. Within a few posts i will put up the official answer and explanation which I do not agree with at all.

6. Building conductors designated as ?RHH? are considered:
A) covered.
B) insulated.
C) insulated as suitable for dry and wet locations.
D) covered as suitable for dry and wet locations.
 
310.8 Locations.


(B) Dry and Damp Locations. Insulated conductors and cables used in dry and damp locations shall be Types FEP, FEPB, MTW, PFA, RHH, RHW, RHW-2, SA, THHN, THW, THW-2, THHW, THWN, THWN-2, TW, XHH, XHHW, XHHW-2, Z, or ZW.
 
ivsenroute said:
What appears to be an easy question does not make sense when you find out the "correct" answer and explanation. Look it up then posts your answer. Within a few posts i will put up the official answer and explanation which I do not agree with at all.

6. Building conductors designated as ?RHH? are considered:
A) covered.
B) insulated.
C) insulated as suitable for dry and wet locations.
D) covered as suitable for dry and wet locations.
Click to expand...

-A- could mean covered in dirt so it's not -A-
-B- is what it is "insulated" or it would be bare
-C- no "W" so no wet location
-D- same reasoning as "A"

So logic would say "B".
 
When I looked at Table 310.13 I noticed that RHH is for Dry and Damp so immediately I decided that C & D were out.

That means that it is either A or B

When I looked at the Insulation column I noticed that it is left blank, completely blank so I ass-u-med that that meant it is not insulated. I looked up the definition of "Insulated Conductor" and decide that since the column is left blank then I can eliminate B as an answer.

Looking at answer A (only one left by default) i see that the outer covering column states that it is Moisture Resistant, Flame Retardant, Non-Metallic covering. Of course it has a note (1) so I looked up that note and it said "Some insulations do not require and outer covering" which seemed to perplex because that can mean that the wire can be insulated or just have an outer covering with no insulation.

I picked A out of frustration and of course I was wrong.

I did not see 310.8 and think this is a very misleading, poor question,.......probably because I got it wrong.

So the answer is B of course, Insulated. Congrats to those who did not overthink and miss the obvious like me.
 
Since RHH is an insulation type, I'd never even think to call it only covered. Covered conductors are normally the bare conductor in a consist of a cable, covered by the cable jacket. I think that conductors with paper on them are considered covered only too, but I do know that there were paper insulated conductors at one point in history.
 
Paper is an approved insulator for underground service or by special permission but is shown to have a Lead Sheath as a covering. 85C - 185F

Go figure.

Commercial grandfathering is over in PA in April and I am taking my Commercial Inspectors test tomorrow morning and preparing for it. Hence this whacky questions.
 
ivsenroute said:
I am taking my Commercial Inspectors test tomorrow morning and preparing for it.
Click to expand...

FWIW ~ I never study the night before a test.... "Know what you know, don't know what you don't know".

Which reminds me....I have some paperwork to submit for a test:wink:
 
Look in article 100 under definitions:

conductor: covered
and
conductor: insulated

The handbook explains that "insulated" means it meets certain product standards (like UL 83). Only wires that meet the standards are allowed to be marked with the designations in 310.13.

Steve
 
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