This is from an installer in St Croix about and issue he had. Any thoughts?<br><br><p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;"> I have a client w/ an older solar array.
They are at least as old as 1991, and I installed 1 new panel and new SW4048 and
L-16 bats in Jan 2000. The 24 modules are Solarex "SX 110" but they have a 2.1
Isc and they measure 17.5" x 42 " each I believe they are @ 35W each. They
are wired 4 modules in series , 6panels@ 48V nom. w/ 2 panels parallel in J
box on roof w/no fuse, or diode. 3 pos </span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">power
leads go down to SQ D fused Disconnect (3, 10A FLNR fuses).
</span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">After
opening PV disconnect at array site, and measuring Voc on each input terminal
(@ 75Voc each) I measured Isc . I got 3.9 on West, 1.9 in middle, and 3.9 on
east. After I had finished w/this measure, I Heard a loud pop, and when we
inspected array found 1 panel w/cracked glass and an electrical blow out on
underneath on back sheet of module. </span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">This
was the East panel, and measuring Isc on all again, got 3.9 West, 1.9 Mid, and
1.9 Isc East. </span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">I did
not wire the array, though I did rewire the j box w.new busses. Interestingly,
each 48 V panel has 2 Pos wires, each measuring 75 Voc .; i.e. each output
circuit (to 10A fuse) has 4 Pos wires coming into it. Though I did not confirm
w/isc test, I imagine that 2 wires were used for Pos on each 48 V panel. There
are also a total of 4 ve wires for ea panel as well, all ve on 1
buss.</span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">All
panels were in direct sun when this blowout event occurred. Also, all modules
had severe darkening of cells.</span></font></p>
<p class="MsoNormal"><font size="2" face="Calibri"><span style="font-size: 11pt;">Care
to comment on this, what happened and why?</span></font></p><br clear="all"><br>-- <br>Jason Lombard<br>Open Hand Solar LLC.<br>Certified Sustainable Building Adviser<br><a href="http://www.openhandsolar.com">www.openhandsolar.com</a><br>
505 795 8646<br><br>"I'd put my money on solar energy I hope we don't have to wait 'til oil and coal run out before we tackle that."<br><br>Thomas Edison<br>