good point any conduit can carry moisture, and conduits from hot to cold can hve condensation, air flow should be avoided. the duct seal is good for this
darryl
--- On Wed, 8/26/09, boB Gudgel <boB at midnitesolar.com> wrote:
> From: boB Gudgel <boB at midnitesolar.com>
> Subject: Re: [RE-wrenches] raintite box mounting angle
> To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Wednesday, August 26, 2009, 5:05 PM
> Conrad Geyser wrote:
> >
> > We always fill any conduit at the point of building
> penetrations for air sealing. Otherwise in winter, not only
> will the conduit get house moisture condensing inside of it,
> but it will act a a nice thermo siphon for pulling warm air
> out of the house…..
> >
>
> Just a note here...
>
> All six of the MidNite PV combiner boxes are rain "proof",
> but allow moisture to escape.
>
> boB
>
>
>
>
>
>
>
>
> >
> ------------------------------------------------------------------------
> >
> > *From:* re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org]
> *On Behalf Of *Wind-sun.com
> > *Sent:* Tuesday, August 25, 2009 11:49 AM
> > *To:* jryago at netscape.com;
> RE-wrenches
> > *Subject:* Re: [RE-wrenches] raintite box mounting
> angle
> >
> > It is almost impossible in a normal installation to
> get a totally waterproof enclosure.
> >
> > What you describe with the flooded box is more common
> than people might think.
> >
> > What causes most of that is condensation. Humid air
> gets sucked into the enclosure at night or whenever else it
> cools off. The water then condenses inside. Next day, the
> box heats up again and the air expands a bit again, but the
> water has already condensed and cannot get out.
> >
> > That is why the weep hole as you noted is mandatory,
> especially in areas with high humidity. But we have seen
> this even in the desert regions of Arizona and CA, so it can
> happen anyplace over long periods of time.
> >
> >
> ..................................................................................................
> > Northern Arizona Wind & Sun - Electricity >From
> The Sun Since 1979
> > Solar Discussion Forum: http://www.wind-sun.com/ForumVB/
> >
> ..................................................................................................
> >
> > ----- Original Message -----
> >
> > *From:* Jeff Yago
> <mailto:jryago at netscape.com>
> >
> > *To:* kirk at vtsolar.com
> <mailto:kirk at vtsolar.com>
> ; RE-wrenches
> > <mailto:re-wrenches at lists.re-wrenches.org>
> >
> > *Sent:* Tuesday, August 25,
> 2009 8:40 AM
> >
> > *Subject:* Re: [RE-wrenches]
> raintite box mounting angle
> >
> >
> > I am getting more convinced
> that there is no such thing as a
> > water-tight electrical
> enclosure, regardless of gasket covers and
> > sealed openings. We always
> drill a very small "weep-hole" in the
> > bottom of an enclosure. We
> have found this is too small to allow
> > insects to enter, but will
> drain any leaks or moisture that gets
> > condensed into a liquid. I was
> recently called by the owner of a
> > large pole mounted array (that
> was installed by another firm )
> > when the system stopped
> working and the originally installer was
> > long gone. I absolutely swear
> to you that when I pulled the covers
> > off several electrical
> junctions boxes, water POURED out of the
> > enclosures! I am not talking
> about wet, I am saying about a quart
> > of water was being held inside
> each enclosure by their water-proof
> > gasketed covers. Needless to
> say, all of the electrical terminals
> > and wire connectors inside
> these junction boxes were badly corroded.
> >
> > I know they make totally
> water-proof electrical equipment for
> > under-water applications, but
> have found most outdoor rated
> > electical enclosures will get
> some water inside and that includes
> > under-ground conduit. Take
> some advice and regardless of mounting
> > orientation, drill a small
> weep-hole in the bottom if there is not
> > one provided by the
> manufacturer.
> >
> > Jeff Yago
> >
> > DTI Solar
> >
> >
> ------------------------------------------------------------------------
> >
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