Mains wiring question (USA)

[[email protected]]

Really,..
I have a state inspector friend I should have log in here., What he
tells me and shows me from the book and local codes, is totally
different what what I've seen here, when it comes to house residential
wiring and industrial installations.

Why don't you bring your "state inspector friend" around so he can show us how
wrong you are?

I think he'd like showing you some code books. He also does adult
refresher courses and he tells me that it's hard to believe the number
of those that have been in the business for years having a miss
conception of what they think should be done..

This sounds like fun, but of course you're talking through your ass, as
always.

He used to be part of the NEC group committee but since he has retired
from tech school teaching he has pulled out of that.

Your typical bullshit.

Have fun with your many wonders..

Yes, sometimes I wonder how someone can be as stupid as you and still manage
to breathe.

I'll get off this soap wagon now because I know where it's leading.

To you being shown for the fool you are, as usual. That's what you risk every
time you open your mouth, Jamie.

Too many bone headed people here..

All of them wrong except you, right Jamie?

I'll stick with the NEC and local codes for now.. Thank you very much..

FOS, as always.

 

[Rich.]

A 1-story, flat-roof house (no basement) in California is going to be
re-covered, so it's a prime time to do some electrical upgrades.

The local building inspector says that romex cable run on the roof (before
foam insulation is put on) must be covered by sheet metal stapled over it
to
protect from nail incursion (yes, he knows this is a *foam* roof, no
shingles, etc., but no matter).

I've asked electrical supply wholesalers about this but they have no
product
such as this.

Is this something an electrical supplier would have? Or is just a roll of
sheet metal stock what's called for?

Thanks.

From the 2008 edition of the NEC:
300.4 Protection Against Physical Damage ...

(A) Cables and Raceways Through Wood Members.

(1) Bored Holes. In both exposed and concealed locations, where a cable- or
raceway-type wiring method is installed through bored holes in joists,
rafters, or wood members, holes shall be bored so that the edge of the hole
is not less than 32 mm (1¼ in.) from the nearest edge of the wood member.
Where this distance cannot be maintained, the cable or raceway shall be
protected from penetration by screws or nails by a steel plate(s) or
bushing(s), at least 1.6 mm (1/16 in.) thick, and of appropriate length and
width installed to cover the area of the wiring.

Exception No. 1: Steel plates shall not be required to protect rigid metal
conduit, intermediate metal conduit, rigid non-metallic conduit, or
electrical metallic tubing.

Exception No. 2: A listed and marked steel plate less than 1.6 mm (1/16 in.)
thick that provides equal or better protection against nail or screw
penetration shall be permitted.

There is no provision to exempt type AC cable ("bx") from the nail-plate
protection requirements.

 

[JosephKK]

There is no logic to the declarations of building inspectors. He says if we
choose to use romex (our option), we must cover it with metal strips wherever
it is exposed.

Another option is to use armored (MX) cable or EMT conduit. Romex seems the
simplest if we can find a simple metal strap to cover it.

Thanks.

Wow. Foam roof and EMT vs romex, i would take a really serious look
at EMT (and perhaps simple conductors instead of romex).

 

[JosephKK]

On top of this flat-roofed building, picture a sea of plywood as far as the
eye can see. Holes are drilled into the plywood where walls intersect the
roof and romex is dropped into the walls. From this point to the distant
location of the load (breaker) panel the romex is laid on the plywood and
stapled down. Over this romex must be attached some kind of protection,
declared by the local building inspector.

Thanks.

If the romex is already in, just add the "shields" using raceway
components.

 

[Josepi]

EMT may not be considered mechanical protection as Rigid PVC is in your
location or codebook. EMT and any form of rigid conduit are not
interchangeable.



Not here. The plastic is double the cost of EMT. They figure the ease
of installation makes it worth more.




bud-- wrote:

Rigid PVC would be cheaper than EMT.

 

[Charlie E.]

Wow. Foam roof and EMT vs romex, i would take a really serious look
at EMT (and perhaps simple conductors instead of romex).

Actually, thinking about what he is doing, i would be real tempted to
go with something solider, like rigid, instead of EMT...

 

[Charlie E.]

Hi John,
Not really. Rigid is a lot thicker and harder to work with than EMT,
but it lasts literally forever if not physically damaged. EMT will
dent if you look at it sideways... ;-)

Charlie

 

[Jamie]

No it is not.

rigid is like water pipe..

 

[Jamie]

Hi John,
Not really. Rigid is a lot thicker and harder to work with than EMT,
but it lasts literally forever if not physically damaged. EMT will
dent if you look at it sideways... ;-)

Charlie

Actually, you don't need to look it at side ways for it to get dented,
we get it delivered that way, or at least that's what the guys lead me
onto believing!

 

[Rich.]

No, emt is 1/16" thick and uses fittings, while rigid is 1/8" thick and is
threaded.

 

[JosephKK]

John F., there is significant wall thickness differences between EMT,
IMC, and GRC. NOT the same. For more see NEC articles 358 EMT, 342
IMC, and 344 RMC. Or use your favorite search engine with the added
info i just provided.

 

[JosephKK]

EMT is widely used in the electrical trade. It is adequate for almost
all uses.

It sure is, inside buildings. Once you go outside it tends to be RMC
(aka GRC). Though rigid PVC (aka RNC) is quite common also.

Rigid is not used very often.

My experience is different.

There is conduit that is between rigid and EMT in wall thickness - IMC
- intermediate metal conduit. It is probably used more than rigid.

I hardly ever see that used.

None of these need nail plates when they are near the edge of a stud.
Neither dies rigid PVC conduit. Apparently the NEC considers them to
be reasonable protection.

If you want to get specific about the case i can look it up in my
copy. I have 2005 here at home and 2008 at work.