<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000066">
<font face="Verdana">Not sure why the following reply which I posted a
couple of hours ago never got posted on the list. I can offer more
detail as to the considerations the test process must be given for this
application if anybody is interested.<br>
<br>
Begin previous message:<br>
<br>
</font><font face="Verdana">The testing for the HU series switches was
performed by Square D according to a procedure that I wrote when
working with SMA. The procedure was reviewed and accepted by UL as
valid for the dedicated purpose of PV disconnect when used with the SMA
SB2500.</font><br>
<pre class="moz-signature" cols="72">See ya!
Marv
707 763-4784 x7016
</pre>
<br>
<br>
<pre class="moz-signature" cols="72">See ya!
Marv
707 763-4784 x7016
</pre>
<br>
<br>
Bill Brooks wrote:
<blockquote cite="mid:021501ca9320$4d2e0aa0$e78a1fe0$@com" type="cite">
<meta http-equiv="Content-Type" content="text/html; ">
<meta name="Generator" content="Microsoft Word 12 (filtered medium)">
<title>Re: [RE-wrenches] Square D DC disconnects</title>
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="Section1">
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">David,<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">The
state by the Eaton guy at SPI shows that person’s lack
of understanding. The person I talked to was adamant that all
disconnects had
to be tested to the disconnect standard that assumes a high
(10,000-amp)
current source behind any fault. Switch openings are also tested based
on the
inductance in the circuit since that has a major impact on the size and
duration of the arc—especially in ac systems.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">Square
D did an evaluation based on the limited fault currents
and inductance in PV system circuit that has no batteries. I believe
their
evaluation is valid. The issue is that there is no specific test at UL
yet—that’s
why UL did not list it (I’m pretty sure they were involved at some
level,
but that is impossible to prove). It will probably be added to UL1741.
Perhaps
that was what the Eaton rep was referring—we’ll give him the
benefit of the doubt.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">I
still use my basic rule similar to the rule for politicians—how
do you know if a marketing guy is lying?== his lips are moving.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">Bill.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<div>
<div
style="border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif";">From:</span></b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif";">
<a class="moz-txt-link-abbreviated" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a class="moz-txt-link-freetext" href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>David
Brearley<br>
<b>Sent:</b> Monday, January 11, 2010 3:41 PM<br>
<b>To:</b> RE-wrenches<br>
<b>Cc:</b> 'Tim Townsend'<br>
<b>Subject:</b> Re: [RE-wrenches] Square D DC disconnects<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif";">Thanks,
Bill.<br>
<br>
Glad to hear you think the HU series is still a good option.<br>
<br>
When I was making the rounds at SPI, I stopped by the Eaton booth and
got the
sense that they were gunning for Square D. They made light of Square
D’s
self-certification of the HU series discos. The rep also made a
statement about
the new Eaton dc discos being the only ones designed to meet UL1741
requirements. When I got home, the first thing I looked up was
690.4(D). This
doesn’t say anything about dc disconnects needing to be listed to some
special PV standard. <br>
<br>
Is there a movement in this direction? Is there a UL1741 standard for
dc discos
that is somehow different that the standard used for other dc
disconnects?<br>
<br>
Best,<br>
<br>
David <br>
<br>
On 1/11/10 5:28 PM, "Bill Brooks" <<a moz-do-not-send="true"
href="billbrooks7@yahoo.com">billbrooks7@yahoo.com</a>>
wrote:</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif"; color: rgb(31, 73, 125);">David
and Kirpal,<br>
<br>
It is ultimately up to the AHJ whether or not they accept the
Schneider/Square
D self certification. That is a judgment call the installer needs to
clear with
the AHJ. That being said, having Square D behind the rating of a switch
is a
whole lot more than any one of the smaller companies making equipment
for the
PV industry. <br>
<br>
I will continue to use the 30, 60, and 100-amp versions in the way
recommended
by the manufacturer because it is a huge saving in cost and they are
well made
switches. I will also check with the local AHJ before installing them
in case
they are not going to pass it. You have to remember you are working
with one of
the largest electrical suppliers in the world. They have a huge
reputation with
local jurisdictions.<br>
<br>
Eaton has been in the process of trying to make a big deal out of this
issue
since they want a piece of the market. Fortunately, they are starting
to build
products specifically for the PV industry, which I applaud. However,
they need
to be given a hard time for the way they have tried to imply that all
Square D
switches are not properly listed. They won’t admit to that because they
would end up in a legal battle, but that is essentially what they have
been
doing. Square D still has the largest selection of dc-rated equipment
on the
market. Eaton has a long way to go. <br>
<br>
In a recent project that I reviewed, the engineer pulled the Square D
400-amp
disconnect and replaced it with an Eaton disconnect at the insistence
of the
Eaton rep. The Eaton product was not properly rated or listed for the
voltage
while the Square D product was. This is the insanity that needs to stop.<br>
<br>
Bill.<br>
<br>
<br>
</span><span
style="font-size: 11pt; font-family: "Calibri","sans-serif";"><br>
</span><b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif";">From:</span></b><span
style="font-size: 10pt; font-family: "Tahoma","sans-serif";"> <a
moz-do-not-send="true" href="re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a moz-do-not-send="true"
href="mailto:re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>]
<b>On Behalf Of </b>David Brearley<br>
<b>Sent:</b> Monday, January 11, 2010 11:39 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] Square D DC disconnects<br>
</span><br>
<span style="font-size: 11pt; font-family: "Calibri","sans-serif";">Kirpal,<br>
<br>
Have you checked out the SolarBOS disconnecting combiners? Their 28A
version
might be ideal for large resi or small commercial applications. For
larger
projects, Blue Oak PV Products and AMtec Solar also have disconnecting
combiners.<br>
<br>
Thanks for sharing the updated Square D tech note. I had no idea that
the
Square D HU Series disconnects were not UL-listed when used as
described in the
older tech notes. The fact that this is not a UL-listed use of the
heavy duty
safety switch, pretty much means that it is not an option for
integrators. As
far as I know, there is no other product that is listed for this use. <br>
<br>
David Brearley, Senior Technical Editor<br>
<i>SolarPro</i> magazine <br>
NABCEP Certified PV Installer ™<br>
<a moz-do-not-send="true" href="david.brearley@solarprofessional.com">david.brearley@solarprofessional.com</a><br>
<br>
<br>
On 1/9/10 4:14 PM, "Kirpal Khalsa" <<a moz-do-not-send="true"
href="solarworks@gmail.com">solarworks@gmail.com</a>>
wrote:</span><o:p></o:p></p>
<p class="MsoNormal"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif";">Hi
All......</span><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span
style="font-size: 11pt; font-family: "Calibri","sans-serif";"><br>
I recently came across a revised technical bulletin from square D ( <a
moz-do-not-send="true"
href="http://ecatalog.squared.com/pubs/Electrical%20Distribution/Safety%20Switches/Heavy%20Duty/3110DB0401.pdf">http://ecatalog.squared.com/pubs/Electrical%20Distribution/Safety%20Switches/Heavy%20Duty/3110DB0401.pdf</a>
)......we have for years been using the Square D DC Disconnect of
various
amperages (30, 60, 100) as disconnects leading upto the inverter from
the
array.....we have frequently wired one string to each of the three
poles of the
disconnect......we have had this configuration inspected by inspectors
regularly with approval everytime......this new revision of the
document from
Square D shows this is no longer a UL listed method.....they are now
stating in
this document that they are "self certifying" this technique.......have
any of you come across this or know why Square D has back tracked? <br>
<br>
Something else I noticed is that they have raised the amperage rating
on the
30A disconncect per pole by 2 amps from 18 to 20 which is good
especially when
using higher amperage modules like Evergreen ES-A series which would
not have
ben allowed to use the 30A disconnect as the short circuit current
rating was
too high for the derated poles. <br>
<br>
This is not a huge concern as more and more of the inverters we are
using these
days have an appropriate disconnect included with the inverter negating
the
need for an additional stand alone disconnect. <br>
<br>
On a side note............Are there any other manufacturers making <u>listed</u>
muiti pole DC disconnects in which each pole can handle one string?
Also there
is definately a need for roof mounted multi string (1-4 strings)
combiner boxes
with integrated DC disconnects for residential applications that have a
reasonable price.......any one know if any?<br>
<br>
<br>
<br>
<br>
<br>
</span><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><span
style="font-size: 10pt; font-family: Consolas;"><br>
</span><span
style="font-size: 11pt; font-family: "Calibri","sans-serif";"><br>
<br>
</span><o:p></o:p></p>
</div>
<pre wrap="">
<hr size="4" width="90%">
_______________________________________________
List sponsored by Home Power magazine
List Address: <a class="moz-txt-link-abbreviated" href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a>
Options & settings:
<a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a>
List-Archive: <a class="moz-txt-link-freetext" href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a>
List rules & etiquette:
<a class="moz-txt-link-abbreviated" href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a>
Check out participant bios:
<a class="moz-txt-link-abbreviated" href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a>
</pre>
</blockquote>
</body>
</html>