<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">boB covered the main points perfectly.<br><br>Manufacturers of UL-certified products are subject to unannounced spot-checks several times a year by the issuing NTRL to verify the products coming off the production line are absolutely identical to the products submitted for UL testing. Any major deviation in the production units from lab-tested units can result in immediate de-certification and possible recall of any affected product(s). "Major" in this case could be different software, mechanical changes, or a substitution of any components that affect safety or unit operation in any manner with unauthorized components .. for openers.<br><br>By the way .. for anyone who's not met boB in person .. I had the good fortune to do so at the Midwest Renewable Energy Fair in Wisconsin this past June. Great guy.<br><br>Dan<br><br><br>--- On <b>Tue,
10/19/10, boB Gudgel <i><boB@midnitesolar.com></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: boB Gudgel <boB@midnitesolar.com><br>Subject: Re: [RE-wrenches] Inverter 1741 Listing Process<br>To: gilligan06@gmail.com, "RE-wrenches" <re-wrenches@lists.re-wrenches.org><br>Date: Tuesday, October 19, 2010, 12:42 AM<br><br><div id="yiv595958572">
On 10/18/2010 9:53 PM, Matt Lafferty wrote:
<blockquote type="cite">
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"><font color="#0000ff" face="Arial" size="2">Thanks for the info
Dan and boB.</font></span></div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"></span> </div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"><font color="#0000ff" face="Arial" size="2">What production tests
required to maintain listing? Do you happen to know if there
is a different regimen for micro vs string vs central
inverters? </font></span></div>
</blockquote>
<br>
<br>
You mean, a difference between the two when UL, ETL, CSA comes by
for their pop inspection ??<br>
<br>
Off hand, I don't see why one inverter would be given any different
kind of attention than the other<br>
type. The UL/ETL followup inspections are basically to make sure
you are following the proper<br>
manufacturing and testing processes such as, software version,
verification that you are using<br>
UL recognized sources of parts and materials, hi-potting at the
correct voltages, etc.<br>
<br>
<br>
They are both grid-tie inverters so the testing processes are very
similar.<br>
<br>
I'm sure that Dan will pick up on anything important that I
forgot.<br>
<br>
boB<br>
<br>
<br>
<blockquote type="cite">
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"></span> </div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"><font color="#0000ff" face="Arial" size="2">I'm working on
developing a detailed commissioning procedure. Detailed yet
generic. There will be at least two versions for inverters.
One for string and one for central. In my book, central
inverters have re-combiners (standalone or integral) and
string inverters don't. </font></span><span class="yiv595958572312173504-19102010"><font color="#0000ff" face="Arial" size="2">I'm trying to understand which functions are
tested in the factory on every unit so I can avoid
unnecessary duplication by the commissioning people.</font></span></div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"></span> </div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"><font color="#0000ff" face="Arial" size="2">Thanks in advance for
any light you can shed on the subject!</font></span></div>
<div dir="ltr" align="left"><span class="yiv595958572312173504-19102010"></span> </div>
<div dir="ltr" align="left"><strong><i><span style="font-family: 'Monotype Corsiva';">Matt Lafferty</span></i></strong></div>
<div dir="ltr" class="yiv595958572OutlookMessageHeader" align="left" lang="en-us">
<hr tabindex="-1">
<font face="Tahoma" size="2"><b>From:</b>
<a rel="nofollow" class="yiv595958572moz-txt-link-abbreviated" ymailto="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank" href="/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a rel="nofollow" class="yiv595958572moz-txt-link-freetext" ymailto="mailto:re-wrenches-bounces@lists.re-wrenches.org" target="_blank" href="/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On
Behalf Of </b>Exeltech<br>
<b>Sent:</b> Monday, October 11, 2010 10:04 AM<br>
<b>To:</b> RE-wrenches<br>
<b>Subject:</b> Re: [RE-wrenches] Inverter 1741 Listing
Process<br>
</font><br>
</div>
<table border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td valign="top">Matt,<br>
<br>
The 5-minute delay is verified in the group of inverters
sent to the test laboratory. Then, as long as the
software and hardware don't change, it's presumed the
delay in all production units meets the value(s) measured
in the tested units.<br>
<br>
An alteration in either hardware OR software can result in
a unit being required to completely re-test (as Bob
pointed out). NRTLs get copies of the source code and can
and do periodically compare their copy as submitted with
the original test units to the software being programmed
into the inverters during production to verify it's the
same.<br>
<br>
NRTLs conduct unannounced "field audits" by simply showing
up on site and randomly selecting various aspects of the
product for verification -- including the software.<br>
<br>
The overall UL1741 certification process is extremely
complex, very time consuming, and quite expensive.<br>
<br>
<br>
Dan<br>
<br>
<br>
<br>
--- On <b>Fri, 10/8/10, boB Gudgel <i><a rel="nofollow" class="yiv595958572moz-txt-link-rfc2396E" ymailto="mailto:boB@midnitesolar.com" target="_blank" href="/mc/compose?to=boB@midnitesolar.com"><boB@midnitesolar.com></a></i></b>
wrote:<br>
<blockquote style="border-left: 2px solid rgb(16, 16, 255); padding-left: 5px; margin-left: 5px;"><br>
From: boB Gudgel <a rel="nofollow" class="yiv595958572moz-txt-link-rfc2396E" ymailto="mailto:boB@midnitesolar.com" target="_blank" href="/mc/compose?to=boB@midnitesolar.com"><boB@midnitesolar.com></a><br>
Subject: Re: [RE-wrenches] Inverter 1741 Listing Process<br>
To: <a rel="nofollow" class="yiv595958572moz-txt-link-abbreviated" ymailto="mailto:gilligan06@gmail.com" target="_blank" href="/mc/compose?to=gilligan06@gmail.com">gilligan06@gmail.com</a>, "RE-wrenches"
<a rel="nofollow" class="yiv595958572moz-txt-link-rfc2396E" ymailto="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" href="/mc/compose?to=re-wrenches@lists.re-wrenches.org"><re-wrenches@lists.re-wrenches.org></a><br>
Date: Friday, October 8, 2010, 9:26 PM<br>
<br>
<div id="yiv595958572yiv1780317400">On 10/8/2010 6:04 PM, Matt
Lafferty wrote:
<blockquote type="cite">
<div><span class="yiv595958572yiv1780317400078505600-09102010"><font face="Arial" size="2">Hola Wrenches,</font></span></div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"></span> </div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"><font face="Arial" size="2">Does anybody know off
the top of their head if the <em>"5-minute-wait-to-interconnect"</em>
function is tested on 100% of inverters
produced? <em>(i.e. every single inverter is
tested with AC & DC within the start
parameters of the unit for at least 5
minutes)</em></font></span></div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"></span> </div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"><font face="Arial" size="2">Thanks!</font></span></div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"></span> </div>
<div><span class="yiv595958572yiv1780317400078505600-09102010"><font face="Arial" size="2">Matt Lafferty</font></span></div>
</blockquote>
<br>
Good question. I bet it's not 100% tested because if
the software does not<br>
change, then they may just not wait the extra 5
minutes in order to save money on testing.<br>
<br>
Or, maybe they do a random sampling for this test.<br>
<br>
Theoretically, it shouldn't matter as long as the
software does not change<br>
and the hardware is tested enough in other ways, like,
timers and clocks etc.<br>
<br>
BTW, Nowadays, there are two options for manufacturers
of grid interactive inverters....<br>
<br>
And the UL spec has gotten more stringent.<br>
<br>
One option is that you have to have the code
(software) blessed by the NRTL in a separate process
(another UL specification, (UL 1998 –Software in
Programmable Components")<br>
<br>
OR, if they don't go for that option, then if software
changes need to be done to the inverter, the inverter
must (technically) go through the UL1741 listing
process all over again.<br>
<br>
boB</div>
</blockquote>
</td>
</tr>
</tbody>
</table>
<br>
</blockquote>
<br>
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