<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">You\u2019re losing about a third of your voltage so one cell bank is out of the circuit. Either a shorted closed diode (more likely IMHO) or fully open connections somewhere in a cell bank (probably visible if between cells, if in the jbox, well it depends on the jbox). <div><br></div><div>If you short circuit the module, or connect it to a load, and with enough irradiance, you should be able to see the diode heat up with an IR camera or maybe even locate it - or the associated cell bank, which will also be hotter than the two good ones - with another type of temperature sensor. </div><div><br></div><div>If you can access the diode and isolate it, most DMMs have a diode year function. </div><div><br><div id="AppleMailSignature" dir="ltr">Brian</div><div dir="ltr"><br>On Jun 11, 2019, at 2:38 PM, Drake <<a href="mailto:drake.chamberlin@redwoodalliance.org">drake.chamberlin@redwoodalliance.org</a>> wrote:<br><br></div><blockquote type="cite"><div dir="ltr">
Hello Wrenches,<br><br>
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>
The module is an LDK 240, which means no warranty. <br><br>
Thanks,<br><br>
Drake <br><br>
<a name="_MailAutoSig"></a>Drake Chamberlin<br>
<i>Athens Electric LLC<br>
OH License 44810<br>
CO License 3773<br>
NABCEP Certified Solar PV <br>
740-448-7328<br>
</i><a href="http://athens-electric.com/">http://athens-electric.com/</a>
<br><br>
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