Flexible conduit outdoors

Mon Mar 15, 2010 8:22 pm   

Michael A. Terrell <mike.terrell_at_earthlink.net>
wibbled on Monday 15 March 2010 16:11



Without making a big deal of it, it is generally polite to say what
jurisdiction you're in if you are asking a question where the answer varies
by jurisdiction! The Internet is not longer just ARPANet, so unless the
USENET group begins with a country code, one has to assume it's got an
international audience.

Not having a go at the OP or anyone else - honest omission I expect. But if
folk ask a question, it's a bit rude to expect the potential contributers to
play a guessing game when the OP could easily state the fact.

Nuff said from me :-o

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

Mon Mar 15, 2010 9:20 pm   

Hi Tim,

Tim Watts wrote:

I would agree -- *if* the questioner is just looking for
a quick answer (that google et al. can't/won't provide).

However, I actually enjoy hearing "unconstrained" answers.
It exposes you to ideas that you might not otherwise see.
I think this is *particularly* true of "americans" who see
the world as "America" (with little beyond). The idea that
there *can* be a "different answer" -- other than the one
in front of you -- is often enlightening. And, reminds
us that there *are* other ways of doing things.

Which, hopefully, gets one to thinking: "Why is that
answer different? Is it *better*? Or, were other
criteria at play in its formulation?"

E.g., the idea of *not* having an electric outlet in
the bathroom in such a place as convenient as "by the
sink/vanity/mirror" was a surprise to me. Electric
shaver? Hair dryer? Curling iron? Electric toothbrush?
(i.e., are these things simply not used, there? Or, are
"safer" variants produced)

Even within the US, there are different issues that affect
different regions of the country. E.g., here I think nothing
of burying water lines "shallow" (frost line is nonexistent?).
OTOH, I'd never leave a piece of PVC out in the Sun :-/

I think, without hearing these sorts of differences mentioned
(even casually in a discussion about sundial placement, etc.)
helps open people's minds to other ideas.


Yup. Or, respondents can qualify (or not! :> ) their replies.

<shrug>

Mon Mar 15, 2010 9:40 pm   

Hi Richard,

Richard Henry wrote:

I *think* you are supposed to pull "unjacketed" wires in
conduit. I'd have to check the codebook to be sure :-/

Mon Mar 15, 2010 10:07 pm   

On Mar 15, 12:22 pm, Tim Watts <t...@dionic.net> wrote:

Sorry about the omission in the original posting, but I have since
answered the question some time ago: California, USA.

Status report: the job is about half done, using grey UV resistant
SCH 40 PVC conduit and fittings. A word of advice: if you plan to
pull 3 12 AWG solid wires 30 feet, 1/2" conduit is a little tight. I
would use 3/4" conduit if I were to do it again.

Mon Mar 15, 2010 10:07 pm   

D Yuniskis <not.going.to.be_at_seen.com>
wibbled on Monday 15 March 2010 20:20


Though one does have to be a little cautious with safety related regs. I
could give the OP an answer that would be OK under the IEE regs but would be
against the NEC, purely because the assumed conditions are different due to
other regs or the characteristics of the supply itself (often the case WRT
to matters of earthing). As long as I say "this is to the "IEE 17th" then
it's OK, but if I forgot, the poster might read it as "OK to the NEC".


Just for interest, we can have toothbrushes and shavers using one of these
in Zone 2 or beyond (> 0.6m from the edge of bath or shower):

http://www.tlc-
direct.co.uk/Main_Index/Wiring_Accessories_Menu_Index/Ultimate_Index/Ultimate_Shaver_Socket/index.html

The principle there is that the 240V/120V outlets are isolated to a high
isolation level (kV) from the supply *and* earth. The power potential is
limited, so nothing beyond a few 10s of watts and, as of the 17th Edition
IEE Regs, the feed must also be RCD protected (30mA/40mS type).

So no, we are not encouraged to use any other appliance on flex in a
bathroom. En-suite bedrooms now come under the same rules, but as those
rooms are usually quite large, we can take advantage of being allowed normal
sockets > 3m from the shower, or if there is a proper door to the shower
area, then it counts as a separate room anyway. Few people in England have
bathrooms > 3m long (2m long is normal) so no-one has 13A outlets there.

You can have fixed appliances hard wired in (including showers obviously,
which are in Zone 1, over the bath/shower). I used SELV (Separated-from-
earth Extra Low Voltage) 12V lights in mine just so I could have some lights
in the shower area. And they have to be IP56 or better. The IEE Regs are
extremely conservative on the whole and get more so with each edition.

OTOH I seem to remember some americans being surprised when I said we plumb
our gas pipework in copper (usually) ;->


Yeah. My water inlet pipe is only 2 foot underground. No risk of freezing
here but, boy, did the water get cold when the last snow's meltwater got
down to it!


--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

Tue Mar 16, 2010 9:00 pm   

Hi Tim,

[attributions elided]


Yes. Though not *too* cautious -- lest we end up doing away
with the Darwin Awards! ;-)


[Hmmm, either *your* NNTP client -- or mine -- has decided that
a hyphen is a convenient place to break a "word". Obviously,
doesn't recognize the "specialness" of hyphen within a URL]

Does this device extend *back* into the J-box? Or, does it
fit *onto* (in front of?) it?


OK. Obviously power limited.


I don't recall distances from "wet" in the bathroom. In the kitchen,
it tends to be 12" "implicitly". And, most kitchen appliances are
now being offered with very *short* power cords -- no doubt to
keep them from being placed "far enough" from their outlet (which
must be GFCI) to venture *into* a "wet zone". (short cords also
encourage users to unplug the appliances when they clean the
countertops, etc.)


!!! Wow, that's an interesting twist! By "door", do you mean
one of those "crinkly-glass" partitions that acts as a shower
curtain (i.e., doesn't necessarily "wall off" the shower area
completely)?


Our code requires GFCI on bathroom, kitchen, outdoors (except
above certain height). Garage is considered outdoors.

So, you get sleazy builders putting all the bathrooms and
all the outdoor outlets and all the garage outlets on a single
15-20A circuit. (kitchen is mandated to have several 20A
GFCI's) I guess the assumption is that most folks rarely use
outdoor *and* bathroom(s) *and* garage concurrently.

OTOH, it seems pretty obvious that all bathrooms would tend
to be in use concurrently "before work/school" -- and the
folks in those could be equally likely to be using high
power appliances (hair dryer, curling iron, etc.) at the
same time...

And, of course, folks who like to illuminate the exteriors
of their homes with holiday decorations would easily tax
a single GFCI circuit...


Ah, that's a good idea! Though you have to keep the bulbs from
seeing moisture lest they shatter (I assume your lamps are
high wattage to throw some significant amount of light?)


I bury irrigation lines at 6 inches (!). We don't have *really* cold
water, here. And, come Summer, just Hot and Warm. :>

Wed Mar 17, 2010 9:55 am   

D Yuniskis <not.going.to.be_at_seen.com>
wibbled on Tuesday 16 March 2010 20:00


This is Britain - Darwin isn't allowed anymore. Health and Safety roolz OK
man! Sadly...


sorry - it's knode. I like it in so many ways, but it buggers up urls and
Follow-Up headers


Either. You can put it in a 47mm back box sunk into the wall (usual way for
neatness) or into a 47mm surface plastic box (popular with government
housing for cheapness, or for later additions where you can't face fixing
the plasterwork. Same principle applies to all our fittings - can be flush
or surface. Most don't need such a deep box, it's usually 25 or 35mm for
sockets (I prefer the latter, our twin+earth solid copper 2.5mm2 cable is a
bastard to work with at the best of times and when you have upto 3 of them
to fold down, you want some space).

Light switches can be done thinner unless you use lumpy dimmers.


No, real door. Shower screens don't count.


That's a bit similar to the 16th IEE - 17th added RCD on all sockets (except
the odd explicitly marked ones which may be dedicated to a freezer say).
However, it also now requires RCD protection on *all* circuits that are
buried in the wall < 2" below any surface (and building regs [structural
section] usually stops you hacking a chase >2" in most brock walls). So now
everything has to be RCD protected or run in one of the following ways:

(Too many people screwing metal shelves into cables...)

a) Surface mounted (you can see it), naked or in plastic conduit or
trunking.

b) Steel wire armoured cable (sounds like overkill, but it's cheap and not
hard to work with). Often a good solution if the meter is miles away from
the fusebox and you need to safely transport a 100A feed half way round the
house without RCD protection.

c) Copper tubed "pyro"/MICC cable (bare copper wires in magnesium oxide
powder insulation inside copper pipe). Looks nice, especially run on 16th
century stonework or timber framed buildings where anything else would look
pig ugly (Council Hertitage Officers often like it for ancient listed
buildings) and quite thin, but very difficult to terminate and not many
electricians can do it these days.

d) Foil earth-screened cable to a certain British Standard - needs lots of
other pre conditions satisfied, not always practical and very expensive;

e) Good old steel conduit. No one uses this except in factories and car
parks because it is such a bastard to do and very time consuming.


Ooh.


Long live Snowy the Illuminated Snowman!


The IP rating sort sorts the moisture. In my case, 20W per lamp, but I have
6 of them - works quite well, better light distribution than a single 100W
bulb, though getting quality bulbs is a PITA. Last lot I bought for 50p each
died after 4 weeks. In theory they should last forever; cf car lamps with
nice thick filaments.


--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

Thu Mar 18, 2010 8:52 pm   

Hi Tim,

Tim Watts wrote:

Yeah, I forget they won't let you play with *guns*, either :-/
(though it seems to inspire more "creative" mechanisms of
destruction! :> )


So, a cross section looks like a short/stubby "T"?


Understood. Seems like stuffing the service loop back
into the box takes more volume than the fixture itself,
in most cases! (pity folks with flimsy plastic boxes)


Ah, so *literally* "another room".


Here, such outlets have to be truly dedicated. E.g., you can't put
a duplex receptacle there.


Ahh... --------------^^^^ That's a novel way of fixing the problem.
Here, if you route cable within 2" of the nailing surface, you have
to armor the cable (or its surrounds). E.g., you can puchase
thick "nail on" plates to protect cable runs through framing 2x4's
where those runs are "too close" to the edge of the stud.


Understood. Bozo that installed air conditioner here ran #6/3 SE
cable between the drywall and masonary block exterior wall. I.e.,
in the firring channel. He wondered why I wasn't pleased with this!
(e.g., imagine using a stud finder some years hence and picking up
the mass of the 6/3 cable, instead. Then, confidently driving a
nail into this "stud"... X-(


We have "channel mold" for surface mounted wiring. Very low
class, IMO.


There are jurisdictions here (elsewhere in the US) where *all*
cable must be run in EMT -- even stuff buried in walls as part
of new works.


Yeah, amusing to those folks who discover this sort of thing
*after* purchasing a house!

Of course, older buildings have none of the above. E.g., my folks'
house is wired with 12/2 BX. Any place that a "grounded outlet"
was added was just tied to the armor! :-/


Or Pepe the Dancing Saguaro :-/


Hmmm... perhaps something to do with their orientation?