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Re: Flexible conduit outdoors

M

Martin Riddle

Jan 1, 1970
0
Richard Henry said:
Is it legal to run flexible conduit outdoors?

My intent is to go from a breaker box on my deck into a tool shed I
built at one end of it to power one light. My intended route is along
the framework under the deck which is elevated about 2 feet off the
ground.


NEC 2008 says....
(FMC Flexible Metal Conduit)

348.12 Uses Not permitted. FMC shall not be used in the Following:
(1) Wet locations.
(2) in Hoistways, other than permitted in 620.21
(3) In storage battery rooms
(4) In any hazardous (classified) location except as permitted by other
articles in this code.
(5)Where exposed to materials having a deteriorating effect on the
installed conductors, such as oil or gasoline.
(6) Underground or embedded on poured concrete or aggregate.
(7) where subject to physical damage.


So no, not legal if used outdoors. Use PVC schedule 80 instead.


Cheers
 
C

Charlie E.

Jan 1, 1970
0
With some kind of "plastic" insulation overlay it's used all over
Arizona for connecting a local breaker box to objects with some
vibration, such as air conditioning units and pool pumps.

For RH's use though, I would use PVC... but paint it with a good latex
paint, otherwise the UV will deteriorate it.

...Jim Thompson

Yes, there is a special outdoor flex cable, metal covered by grey
plastic. I used it to go from my junction box on the outside of my
house to the sauna's sub-panel for my sauna and pool and other outdoor
electrical. If you want to use rigid for some runs (any you do, if
you are going any distance. That stuff is expensive!) then use
schedule 80, the grey stuff, not the white stuff. It is UV resistant.
When in doubt, follow the NEC! ;-)

Charlie
 
M

Martin Riddle

Jan 1, 1970
0
Jim Thompson said:
With some kind of "plastic" insulation overlay it's used all over
Arizona for connecting a local breaker box to objects with some
vibration, such as air conditioning units and pool pumps.

For RH's use though, I would use PVC... but paint it with a good latex
paint, otherwise the UV will deteriorate it.

...Jim Thompson
--

That’s called LFMC (Liquidtight Flexible metal conduit), which is
allowed outdoors. And more expensive than Schedule 80.
And called out for connecting pool pumps and such.
<http://books.google.com/books?id=im...CCgQ6AEwCA#v=onepage&q=pvc coated FMC&f=false>

Don't know if the OP has that, generally the question stems from what
the person has easy and free access to.

Cheers
 
M

Martin Riddle

Jan 1, 1970
0
Jim Thompson said:
"UV resistant" starts turning black in a year or two in AZ :-(

...Jim Thompson
--

Rustoleum's "Painters Touch" paint has very good UV tolerance. Painted
the Screen frames on Moms house about 10 years ago, and they are still
holding up. Also Glidden Endurance is THE Paint for outdoors. Not
available in the big chain stores, only the little guys carry it.

Cheers
 
T

Tim Watts

Jan 1, 1970
0
With some kind of "plastic" insulation overlay it's used all over
Arizona for connecting a local breaker box to objects with some
vibration, such as air conditioning units and pool pumps.

For RH's use though, I would use PVC... but paint it with a good latex
paint, otherwise the UV will deteriorate it.

...Jim Thompson

Apart from the assumption the NEC applies to the OP, for the record I used
(in the UK) Kopex IP65 pliable plastic conduit to bring meter tails from an
outside box over the wall into my consumer unit. This met the IEE wiring
regs as the cable route required no explicit mechanical protection (by which
the IEE mean armoured cable, copper clad pyro cable or steel conduit).
However the Kopex tube is tough and does afford quite a lot of protection:

http://photos.dionic.net/v/public/bungalow/electrical/20090423180550.jpg.html
http://photos.dionic.net/v/public/bungalow/electrical/2009-04-11-
img_0004.jpg.html
http://photos.dionic.net/v/public/bungalow/electrical/20090423180707.jpg.html

(Ignore the messy local wiring the last one - temp circuit now gone).
 
J

JosephKK

Jan 1, 1970
0
NEC 2008 says....
(FMC Flexible Metal Conduit)

348.12 Uses Not permitted. FMC shall not be used in the Following:
(1) Wet locations.
(2) in Hoistways, other than permitted in 620.21
(3) In storage battery rooms
(4) In any hazardous (classified) location except as permitted by other
articles in this code.
(5)Where exposed to materials having a deteriorating effect on the
installed conductors, such as oil or gasoline.
(6) Underground or embedded on poured concrete or aggregate.
(7) where subject to physical damage.


So no, not legal if used outdoors. Use PVC schedule 80 instead.


Cheers
See also the differences in usage rules between FMC and LFMC.
 
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