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<p>You can test to see if both inverters are staying in sync by just
watching the voltage between L1 and L2 of the</p>
<p>outputs for a while. If they do not deviate much from 240VAC
over several minutes, then they are probably</p>
<p>sync'd OK... You can also help verify this by unplugging the
sync cable and they should start to drift apart in</p>
<p>phase which will be seen eventually reflected in the 240VAC
drifting around and through zero volts and back</p>
<p>up to 240V again.<br>
</p>
<p> Could be seconds or minutes depending on the internal clock
stability.</p>
<p>boB<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 12/22/2019 12:57 AM, Jerry Shafer
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAMUFgmWJNjzG2jRdEtPj10FN8_AKfOHiuWo+5jQ7abF2P1-Fkw@mail.gmail.com">
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<div dir="auto">Well l would start simple and get a sync cable and
make sure that they are al least staying g in correct phasing,
then look closely at the programming, look at the grid voltages
and settings, take it out of IEEE for test purposes only, you
might find out you have a board that's out of calibration
causing the issue but start simple
<div dir="auto">Jerry</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Dec 20, 2019, 9:44 AM
Dave Tedeyan <<a href="mailto:dtedeyan@taitem.com"
moz-do-not-send="true">dtedeyan@taitem.com</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Hi All,
<div><br>
<div>I am someone's last ditch effort to get their system
working which has been non-functional since a few months
after installation, 13 years ago...</div>
<div><br>
</div>
<div>After getting some new batteries in there, I can at
least fire it up. It is a grid tie with battery backup
situation with two Xantrex SW4048 inverters. Each
inverter is kind of like its own system with two Outback
MX60 CC's per inverter, and each inverter powers its own
120V backed up loads panel. They do not see each other
until their 60A single pole breakers in the main panel. </div>
<div><br>
</div>
<div>What seems to be happening is that after turning on
the inverters the AC1 in good light will flash for about
30 seconds, then it syncs up to the grid and the light
stays on solid. But then after a little bit, that light
will start flashing, indicating that the utility power
has been dropped, when it has not actually been dropped.
Then at some point the backed up loads would lose power.
The customer says that every 1-10 minutes, they would
lose the backed up loads for 10-90 seconds. This
happened all night long until they bypassed the
inverters.</div>
<div><br>
</div>
<div>There are a few other things of note:</div>
<div>1. There is a Xantrex GTI for each inverter.</div>
<div>2. I see in the manual there is information about
stacking the inverters, but I am guessing in this setup
this not necessary or would even be counter productive
to stack the inverters. Not sure if the inverters not
being stacked could cause one of them to unsync with the
utility?</div>
<div>3. Neutrals and grounds are bonded in their main
panel, but also in each of the Xantrex DC breaker boxes.
I was going to separate them in the DC breaker boxes,
but found that there is no way to isolate the battery
negative bus from the box itself, and figured it would
be dodgy to unground the enclosure. So I am also not
sure if the multiple N-G bonds could be causing these
issues.</div>
<div><br>
</div>
<div>Does anyone have any ideas?</div>
<div>Cheers, </div>
<div>Dave</div>
<div>
<div>
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<div><b><font
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