From: mja@philabs.philips.com (Michael Amato)
Subject: Follow-up: Exposed wiring and the NEC.
Originator: mja@hercules
Reply-To: mja@philabs.philips.com (Michael Amato)
Organization: Philips Laboratories, Briarcliff, NY 10510
Date: Mon, 17 Aug 1992 15:29:14 GMT


First, I would like to thank all of you who replied to my posting. From 
the responses it seems that my original wiring plan may or may not pass
code, depending on whether or not the inspector thinks I'll need 
protection from physical damage. I have enough NM 12/2 and 12/3 to do the
job, and the surface mount boxes with the built in cable clamps. 
I think I'll go the thin-wall route since I can rotate the boxes 90 deg.
to get at the KO's and just take out the clamps. BX would be easier, but
I have several 3-way switch legs for outside lights and passage lights
that are all ready roughed in NM, and I would not want to go back and
put in BX. 

My town goes by the our states uniform building code (NY) for
framing and plumbing, and the national electric code for wiring. 
(BTW, I have copies of both). A number of posters have warned about
variations in local requirements. I found this when I got my plumbing
permit. The head of the pluming board said that all the local towns use
the NY code as a base, but then tack on seemingly random alterations
which make it a nightmare working from town to town. The electrical
inspector is not a town employee, but is from the NYS Board of Fire
Underwriters. So all the towns in my vicinity get the same inspector.


Steve Bellovin (smb@ulysses.att.com) writes:

>I did.  Here's 336-10(b):

>	Protection from Physical Damage.  The cable shall be protected
>	from physical damage where necessary by conduit, electrical
>	metallic tubing, pipe, guard strings, or other means.  Where
>	passing through a floor the cable shall be enclosed in rigid metal
>	conduit, intermediate metal conduit, electrical metallic tubing,
>	or other metal pipe extending at least 6 inches (152 mm) above the
>	floor.

>As I said in my earlier posting, and as Chris has noted before, the
>Canadian codes are, in general, a bit stricter.  But a lot does depend
>on the inspector.  The commentary in the NEC Handbook stresses protection
>from physical damage:

Steve's comment about the local inspectors interpretation of protection 
from physical damage, in my case, should probably be interpreted as strictly
as possible (ie. BX or conduit). My local inspector will be scrutinizing my
wiring very carefully, so it will pay to be over-cautious.

>Section 300-4 is the part that specifies that cable run through a joist,
>rafter, or other wood framing member be at least 1.25" below the surface.
>(Incidentally, that applies to BX, too -- that's an error in the FAQ.)

Yes, I though that BX also needs to be >1.25" from stud/joist surfaces,
but I didn't want to be argumentative on my first posting to this group.



Dave Golber (dgolber@aero.org) writes:

>I originally wired up my shop with romex.  Then one day I was putting 
>some gardening tools away, and I became away that the sharp edge of the
>shovel, as I hung it up, was passing within a foot of the romex ...
>about 8 feet above the floor.  Then I rewired the place in metal flex.

Point well taken, better protection in this garage will be well worth it.
It will also be used as a workshop, but of the mechanical nature. The old
garage space will be used for my wood working.

>(Think what your inspector says about YOU when YOUR back is turned.)  

Yeah, and since I know he all ready has a low opion of "home owners", 
a little extra hear will hopefully impress him enough ease the rest
of the inspection nit-picking.

>Dave Golber

>I looked in my copy of the code.  I didn't see the particular stuff
>you're talking about ... but that doesn't mean much - it's thick and not
>easy to read.  get your own copy: National Fire Prevention Association,
>Batterymarch Park, Quincy MA 02269.

>Also: it may not be in the National code; it may be in your local code.


Thanks, covered above.


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| Michael Amato  DoD#0639 | "If pro is the opposite of con,       |
| mja@philabs.philips.com | then what is Congress"? - Will Rogers |
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