[RE-wrenches] Square D Disconnects mounted on the slope of the roof.

Mon Nov 11 14:42:33 PST 2013

Dan

Hydraulic actuated breakers like the Classic Heiniman GJ,used in off grid
battery based systems ( now made by Carlon and Airpax, since Henimans's
patent ran out)  it is very critical that they be used in the vertical
position as is marked on the breaker's chassis.  I know this from
experience because I designed and got UL listed the GFI breaker ( common
tripped GJ breakers with a .5 amp ground circuit, common today in many
systems )  for Trace engineering and it kept failing the UL test for no
apparent reason until we discovered the technician at UL was testing it on
it's back, not in compliance with their own UL sticker on the device!  Go
figure.

But in support of Dan's comment, unless marked on the breaker itself,
breaker operation is not dependent on orientation.  Water proof rating of
the enclosure is also another matter and the manufacturer should have
specifics as to the mounting angle that keeps the outdoor rating. The angle
can be very critical for any box that uses a lip to deflect water (NEMA  3R
rating) rather than a seal to keep water out at any orientation (NEMA 4 or
better).  That is more of the issue here along with the fact that breakers
are operating at less than ideal temperature ranges for the designed trip
levels  This would be relevant to the Square D disconnect that I am
familiar with that uses an overlapping lip to get water spary out for it's
3R rating, if it was only tested in a vertical position than tiliting it
would not be within the paramaters of the UL listing.
Bill

On Mon, Nov 11, 2013 at 9:21 AM, Exeltech <exeltech at yahoo.com> wrote:

> Wrenches,
>
> There appears to be some misinformation getting into this thread.
>
> The "trip" mechanism within standard thermal over-current protective
> devices ("OCP devices") is mechanically spring-loaded, and is triggered by
> heat.
>
> Eric mentions below that Square D breakers are tested in a vertical
> orientation only - the implication being that's their only "UL certified"
> position.  If this were true, it would imply the breakers cannot be used in
> any other orientation.  This would potentially limit the Square D OCP
> market to sub-panels and other enclosures where the devices are vertical.
>  Inasmuch as the vast majority of panelboards I've encountered in my 40+
> years in this industry have the breakers stacked horizontally, it would not
> be a wise business decision for the manufacturer to self-inflict such a
> limitation on their product.
>
> This also does not mean any such limitation (real or not) applies to all
> breakers.
>
> By way of example, OCP devices work in a horizontal position, stacked
> "pancake" style in a main panelboard, as well as vertically oriented
> side-by-side in a sub-panel.  In either orientation, they are  in full
> compliance with UL 489, (UL Standard for Circuit Breakers, Switches, and
> Circuit Breaker Enclosures).  If an OCP device *was*
> positionally-sensitive, UL Standards require this sensitivity to be noted
> in the documentation accompanying the device.  Further to that point, UL
> 489 Section 7.1.1.13 states: "In determining if a circuit breaker complies
> with the test requirements, the device shall be mounted or supported as in
> service and tested under conditions approximating those of intended
> operation, except as otherwise noted."
>
> Mounting position notwithstanding, a greater concern would be the ambient
> temperature of a rooftop location, whereby summer heat would tend to make
> the OCP device more sensitive than necessary, potentially causing it to
> trip at an amperage below that of its UL ratings.  While a nuisance, a more
> serious issue arises when operating the OCP device in cold ambient
> conditions, whereby the device may allow MORE than its rated trip current
> to flow.
>
> Per UL 489, OCP devices are tested at either 25C or 40C ambient.  Again
> per UL 489, if an OCP device is to be used in ambient conditions other than
> those two ranges, the acceptable temperature range for that OCP device
> shall be marked on the body of the device.
>
> In UL 489, Supplemental Annex, Section 2, Subsection 2.3.3, mechanical
> vibration testing is conducted with OCP devices oriented vertically,
> horizontally, and inclined 30 degrees from vertical, with all devices
> energized up to 200% of the device rated current during the testing.
>
> Given the preceding, and per implication of UL 489 testing methods, OCP
> devices are NOT positionally sensitive.
>
> In conclusion, if you DO install a rooftop OCP system, and for proper
> protection, please ensure the OCP devices utilized are rated for the
> worst-case ambient temperatures involved.
>
>
> Regards to all,
>
>
> Dan Lepinski
>
>
>
>
> At 09:33 AM 11/8/2013, you wrote:
>
> Hi Kirpal,
>
> All Square D safety switches are UL tested in the Vertical position ONLY,
> so if someone is trying to install a switch in any other position other
> than vertical, that will be between them and the inspector.
>
> Hope this helps.
>
> Eric
>
> ____________________________________________________________________________________
>
> Eric Bentsen  |  Schneider Electric   |  Solar Business  |   UNITED STATES
>  |   Technical Support Representative
> Phone: +(650) 351-8237 ext. 001#  |   Email:
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> Livermore, CA 94551
>
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-- 
Bill Hoffer
161 SE Fourth Ave
P.O. Box 1823
White Salmon, WA 98672
sunengser at gmail.com <bhoffer at sunergyengineeringservices.com>
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