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Hi Dick,<br><br>
Thanks for the suggestion. I will run the concept by the SMA tech
people. I did use the SMA spec sheets in sizing the wiring, but
maybe opening the relays creates fault current at a voltage that will
jump the gap.<br><br>
Drake <br><br>
At 10:50 PM 6/4/2009, you wrote:<br>
<blockquote type=cite class=cite cite="">Hi Drake,<br><br>
I'm sending you some attachments off list as well.<br>
They are Sunny Boy Specs from the SMA Installation Manuals, <br>
which are more complete than those on the SMA data sheets.<br><br>
Note, the Maximum Output Fault Current for the 3000 & 4000 is 30
amps, <br>
while Maximum Overcurrent Protection is 30 Amps.<br><br>
The Maximum Output Fault Current for the 7000 is 57.6 amps, the<br>
Maximum Overcurrent Protection is 50 amps.<br><br>
This might be your problem.<br>
Upsizing the conductors and breakers for the 3000 and 7000 might be a
fix.<br>
SMA tech support could probably shed some light.<br><br>
Dick<br><br>
<br><br>
--- You wrote:<br>
Hi Dick,<br><br>
There are three inverters, all Sunny Boys, a 3000, 4000 and a <br>
7000. The breakers are QO. The AC conductor sizes are #8 for
the <br>
7000, #10 for the 4000 and #12 for the 3000. The breakers are set
<br>
for the NEC ratings of the wire (40 A, 30 A and 20 A.).<br><br>
I sent some information to you off the list with some
attachments.<br><br>
Drake<br>
--- end of quote ---<br>
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<font color="#0000FF">Drake Chamberlin<br>
Athens Electric<br>
OH License 44810<br>
CO License 3773<br>
NABCEP Certified PV Installer </font><font size=1 color="#0000FF">TM<br>
</font><font color="#0000FF">Office - 740-448-7328<br>
Mobile - 740-856-9648 </font></body>
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