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David,<br>
I have pdf copies of the Trace SW manuals, rev. 4.01 (the most
widely used) and rev. 1.0 (the first from around 1993, seldom still
in operation). If you need either one contact me off list. <br>
<br>
For a short period of time around 2002 there was a rev. 4.10 version
of the SW that used a separate component called a Grid Tie Interface
(GTI). The GTI was added to specifically address, as I recall, the
possibility of grid backfeed when the AC input (from a generator, I
think, but this may be incorrect) matched the AC output to the
loads. It was an awkward and short-lived solution that was succeeded
by the (also short-lived) SW+ series, before the XW series replaced
it. I needed to include two of these in a GTBB (early Grid-Tie with
Battery Backup) dual-inverter system that I installed for Jane Fonda
at her New Mexico ranch. As Jerry says, fun times (way more fun than
today, I suspect).<br>
<br>
Your simplest real-world solution, which the utility may or may not
accept, is to run grid power into AC2, the generator input hot
terminal. Then the inverter functions only as an input source. If
the utility determined the 1A backfeed on the basis of its own test,
a retest may be sufficient to ascertain that there's no longer the
possibility of backfeed. <br>
Allan
<blockquote type="cite"
cite="mid:9474f24048b17b99a05df7ed3b374c49@sti.net">
<p id="reply-intro">On 2026-01-12 11:28 am, Dave Angelini Offgrid
Solar wrote:</p>
<blockquote type="cite"
style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">
<div id="replybody1"
style="font-size: 12pt; font-family: Verdana,Geneva,sans-serif;">
<p>Sounds like this could happen. The (really) old SW input
had an option to do this. Disconnect this. Do you have the
manual? I might but not nearby now. Good Luck</p>
<p id="v1reply-intro">On 2026-01-10 1:12 pm, David Palumbo via
RE-wrenches wrote:</p>
<blockquote
style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0;">
<style type="text/css">#replybody1 #v1replybody1 P { margin-top: 0; margin-bottom: 0; }</style>
<div id="v1replybody1" dir="ltr">
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">Wrench,</div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">An
off-grid installation of mine from many years ago has is
now using grid power instead of a generator. The utility
is telling the homeowner that they are going to
disconnect him because his house is back feeding 1 amp
into their grid power.</div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;"> </div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">I've
been retired for many years now and did not do any of
the work to connect the utility power to his Trace
SW4024 inverter/charger. The utility power became
available when his son brought in utility power for his
maple sugaring operation in the neighborhood, and the
father connected power to his house to replace his
fossil fueled generator for additional charging into his
battery bank. They do not have a grid interconnect
sellback agreement with the utility.</div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;"> </div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">I
have no experience with this, but I'm assuming that the
utility grid is seeing power from its input connection
to his Trace SW4024. Does that sound right? If so, is
there a simple solution to fix this problem while
continuing to use the grid power through his SW
inverter? </div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;"> </div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">Thanks
for any advice that may help.</div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">David
Palumbo</div>
<div class="v1v1elementToProof"
style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: #000000;">Hyde
Park, VT</div>
</div>
</blockquote>
</div>
</blockquote>
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