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generators</title></head><body>
<div>Hi Folks,</div>
<div><br></div>
<div>We burnt up a gen set's voltage regulator on an off-grid system
sunny island/sunny boy system when we took the sunny island's off-line
but didn't shut off the sunny boy. So the SB backfed the genny
and fried the very expensive voltage regulator on a 30 KW system.
SMA had us install a relay to tell the SB to shut down as soon as the
AC reference from the SI was gone. Same situation as grid-tie
really in terms of your question.</div>
<div><br></div>
<div>Jeff</div>
<div><br></div>
<div><br></div>
<div><br></div>
<blockquote type="cite" cite>Hi Kelly</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>It is an interesting issue and was just
dicussing this the other day.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>I think what happens if the inverter
backfeeds the genny, the generator voltage will go up, if it goes up
enough, it will go outside the window of the inverter and the inverter
will drop out, voltage will them return to normal, inverter will
reconnect and repeat.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>But I sure wouldn't want to fix the
generator. A relay powered from the grid will take care of the
problem.</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>jay</blockquote>
<blockquote type="cite" cite><br></blockquote>
<blockquote type="cite" cite>peltz power</blockquote>
<blockquote type="cite" cite>On Nov 19, 2008, at 5:24 PM, Kelly
Keilwitz, Whidbey Sun & Wind wrote:</blockquote>
<blockquote type="cite" cite><br>
<blockquote type="cite" cite><tt>Wrenches,<br>
I'm dredging up this subject again (previous postings 6/08) with a
simple question that doesn't seem to have been answered:<br>
<br>
Is there any issue connecting a batteryless grid-tie PV system to the
load side of a panel that is backed-up by a generator on an automatic
transfer switch, when the grid is down and the generator running?<br>
<br>
In this case the PV is 5.7kW, the inverter an SMA 6000, the generator
unknown size/type, but propane, automatic start, and backing up the
entire main panel.<br>
<br>
SMA tech support first said it's OK, then that the generator will blow
up. I can imagine, if the inverter tries to sync with the inverter,
that the voltage could rise, causing the inverter to disconnect, wait
5 minutes, repeat. Is there anything nasty that could happen?<br>
<br>
Thanks,<br>
-Kelly<br>
<br>
<br>
Kelly Keilwitz, P.E.<br>
Whidbey Sun & Wind, LLC<br>
Renewable Energy Systems<br>
NABCEP Certified PV Installer<br>
987 Wanamaker Rd,<br>
Coupeville, WA 98239<br>
PH & FAX 360-678-7131<br>
</tt><a href=""><tt><font
color="#0000FF"><u>sunwind@whidbeysunwind.com</u></font></tt></a><tt><font
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<div>~~~~~~~~~~~~~<br>
Jeff Clearwater<br>
Senior Design Engineer<br>
NABCEP (tm) Certified Solar PV Installer<br>
http://www.nabcep.org/<br>
Village Power Design/NorthEast Solar Design<br>
Turnkey Solar Design & Installation for the Commercial Sector<br>
http://www.villagepower.com<br>
gosolar@villagepower.com<br>
<br>
Voice: 413-259-3750<br>
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