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This is a follow up on an old post about a failed LKD module. I wrote
that I'd give follow up information when it became available. <br><br>
It turned out that some of the fine circuitry on the face of the module
was fried: according to my friend, it looked welded. <br><br>
Drake <br><br>
At 09:59 AM 6/19/2019, drake.chamberlin@redwoodalliance.org wrote:<br>
<blockquote type=cite class=cite cite="">Dave,<br><br>
I gave the module to a friend who is going to go into the J-Box. If there
are any conclusions I can post them on the list, but don't know when she
plans to attempt the repair.<br><br>
Thanks,<br><br>
Drake <br><br>
<br>
<dl><br>
<dd>----- Original Message -----<br>
<dd>From:<br>
<dd>"RE-wrenches"
<re-wrenches@lists.re-wrenches.org><br><br>
<dd>To:<br>
<dd>"RE-wrenches"
<re-wrenches@lists.re-wrenches.org><br>
<dd>Cc:<br><br>
<dd>Sent:<br>
<dd>Tue, 18 Jun 2019 14:57:47 -0400<br>
<dd>Subject:<br>
<dd>Re: [RE-wrenches] Low OC Voltage<br><br>
<br>
<dd>Drake, <br>
<dd>If you want to find out for sure, often you should be able to open up
the jbox on the back and poke around. It certainly is somewhat
destructive, but you may find that either a diode is not the issue, or it
is fixable. Sometimes you do have to pull out potting though. I have
restored modules for second hand use that otherwise would have ended up
in the dump this way. Obviously though it wont be like new anymore.<br>
<dd>Cheers, <br>
<dd>Dave<br><br>
<dd>Dave Tedeyan, PE<br>
</b>
<dd>Senior Engineer | Taitem Engineering, PC<br><br>
<dd>110 South Albany Street | Ithaca, NY 14850<br>
<dd>o. 607.277.1118 x121 f. 607.277.2119<br>
<dd><a href="http://www.taitem.com">www.taitem.com</a><br><br>
<dd>Solar Sustainability Energy Design<br>
<dd>B-Corporation Best for the World 2018 Honoree<br><br>
<br>
<dd>On Thu, Jun 13, 2019 at 10:26 PM
<<a href="mailto:drake.chamberlin@redwoodalliance.org">
drake.chamberlin@redwoodalliance.org</a>> wrote:<br>
<dl>
<dd>The outside temperature was unseasonably cool, maybe 55 degrees.
<br><br>
<br>
<dl><br>
<dd>----- Original Message -----<br>
<dd>From:<br>
<dd>"RE-wrenches"
<<a href="mailto:re-wrenches@lists.re-wrenches.org">
re-wrenches@lists.re-wrenches.org</a>><br><br>
<dd>To:<br>
<dd>"RE-wrenches"
<<a href="mailto:re-wrenches@lists.re-wrenches.org">
re-wrenches@lists.re-wrenches.org</a>><br>
<dd>Cc:<br><br>
<dd>Sent:<br>
<dd>Thu, 13 Jun 2019 09:25:39 -0400<br>
<dd>Subject:<br>
<dd>Re: [RE-wrenches] Low OC Voltage<br><br>
<br>
<dd>Drake, <br>
<dd>At what temperature did you get that reading? If it was very hot,
then that could just be poor temperature characteristics of the module. I
have run into some modules, specifically Suniva's, that just do very
poorly in warm temperatures. Otherwise, if the voltage is approximately
2/3 of what you would expect, then it is usually an issue in the module
jbox. Either a bad diode or failed solder connection. This case is odd,
because it is a little bit more than 2/3 the voltage. So maybe it was
very cold with 1/3 the module not working, or very hot. Also, taking a
look with an IR camera when the system is functioning can often show if
1/3 the module is not working or if there are some bad cells in the
module.<br><br>
<dd>Cheers, <br>
<dd>Dave<br><br>
<dd>Dave Tedeyan, PE<br>
</b>
<dd>Senior Engineer | Taitem Engineering, PC<br><br>
<dd>110 South Albany Street | Ithaca, NY 14850<br>
<dd>o. 607.277.1118 x121 f. 607.277.2119<br>
<dd><a href="http://www.taitem.com">www.taitem.com</a><br><br>
<dd>Solar Sustainability Energy Design<br>
<dd>B-Corporation Best for the World 2018 Honoree<br><br>
<br>
<dd>On Tue, Jun 11, 2019 at 7:05 PM Drake
<<a href="mailto:drake.chamberlin@redwoodalliance.org">
drake.chamberlin@redwoodalliance.org</a>> wrote:<br>
<dl>
<dd>Hello Wrenches,<br><br>
<dd>Would you expect a low open circuit voltage in a module to be due to
a problem in the J-box / diodes or the module itself? The OC voltage read
about 28.3 V, where as the STC OC voltage of the module is 37.3.
<br><br>
<dd>The module is an LDK 240, which means no warranty. <br><br>
<dd>Thanks,<br><br>
<dd>Drake <br><br>
<dd><a name="m_648455691287077203_m_-2450395197685617684__MailAutoSig">
</a>Drake Chamberlin<br>
<dd>Athens Electric LLC<br>
<dd>OH License 44810<br>
<dd>CO License 3773<br>
<dd>NABCEP Certified Solar PV <br>
<dd>740-448-7328<br>
</i>
<dd><a href="http://athens-electric.com/">http://athens-electric.com/</a>
<br>
<br>
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