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<DIV><SPAN class=171392803-12092008>Randy and Dana,</SPAN></DIV>
<DIV><SPAN class=171392803-12092008>Not sure here (never installed a SunTie,
thanks to this list in the early days), but I believe that Xantrex' swap program
ended years ago.</SPAN></DIV>
<DIV><SPAN class=171392803-12092008></SPAN> </DIV>
<DIV><SPAN class=171392803-12092008>I see from your website that you're in
Bellingham, Washington. OK, that explains your low expectations (1,123 kwh/yr
from 1.44kW? Here in NewMex we estimate around double that).</SPAN></DIV>
<DIV><SPAN class=171392803-12092008></SPAN> </DIV>
<DIV><SPAN class=171392803-12092008>I copied some earlier (2001) saved Wrenches
postings about the SunTie (then deleted them). I hope you find them enjoyable
and enlightening.</SPAN></DIV>
<DIV><SPAN class=171392803-12092008></SPAN> </DIV>
<DIV><SPAN class=171392803-12092008>Allan at Positive Energy</SPAN></DIV>
<DIV><SPAN class=171392803-12092008></SPAN> </DIV>
<DIV><SPAN class=171392803-12092008></SPAN> </DIV>
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><BR></FONT></DIV>Dana,
<DIV>I thought Xantrex recalled all the ST1500s and replaced them with XR2500s.
Mine was, years ago. You might check with them about this.</DIV>
<DIV>Good luck,</DIV>
<DIV>
<DIV><SPAN class=Apple-style-span
style="WORD-SPACING: 0px; FONT: 12px 'Times New Roman'; TEXT-TRANSFORM: none; COLOR: rgb(0,0,0); TEXT-INDENT: 0px; WHITE-SPACE: normal; LETTER-SPACING: normal; BORDER-COLLAPSE: separate; orphans: 2; widows: 2; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0">
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'" size=3><SPAN
class=171392803-12092008><FONT size=3>R</FONT></SPAN>andy Brooks</FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'" size=3>Brooks
Solar, Inc.</FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'"
size=3><B><I>Solar Power for People</I></B></FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'" size=3>140
Columbia View</FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'" size=3>Chelan,
WA<SPAN class=Apple-converted-space> <SPAN
class=Apple-converted-space> </SPAN></SPAN>98816</FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'"
size=3>509-682-9646</FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'" size=3><A
href="mailto:Randy@BrooksSolar.com">Randy@BrooksSolar.com</A></FONT></P>
<P style="MARGIN: 0px"><FONT style="FONT: 12px 'Times New Roman'"
size=3>www.BrooksSolar.com</FONT></P></SPAN></DIV><BR>
<DIV>On Sep 11, 2008, at 3:23 PM, Dana Brandt wrote:</DIV>
<DIV><BR class=Apple-interchange-newline></DIV>
<BLOCKQUOTE type="cite">
<DIV style="MARGIN: 0px">Hi all,</DIV>
<DIV style="MARGIN: 0px">I was called out this week to trouble shoot a system
I didn't install.</DIV>
<DIV style="MARGIN: 0px">It's a five year old 1.44kW system with the
following: Sun Tie ST 1500</DIV>
<DIV style="MARGIN: 0px">inverter and 12 Astro Power modules. It only produced
634kWh last</DIV>
<DIV style="MARGIN: 0px">year. With our sun here, the shading, orientation,
equipment, etc. it</DIV>
<DIV style="MARGIN: 0px">should have produced around 1123kWh.</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">I've heard a lot about Sun Tie failures, but don't
know the details.</DIV>
<DIV style="MARGIN: 0px">What are the common failure modes? Is it likely that
a failure of the</DIV>
<DIV style="MARGIN: 0px">Sun Tie would leave it operating, but only producing
half what it</DIV>
<DIV style="MARGIN: 0px">should?</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">When I showed up the system was producing 950W on a
relatively sunny</DIV>
<DIV style="MARGIN: 0px">day - seemed pretty reasonable. After restarting the
inverter it only</DIV>
<DIV style="MARGIN: 0px">produced around 150W. Is the MPPT very, very slow to
find that sweet</DIV>
<DIV style="MARGIN: 0px">spot, or what was going on there?</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">The system is comprised of three strings of 4 modules
each. When I was</DIV>
<DIV style="MARGIN: 0px">there all three strings were producing about the same
current, so that</DIV>
<DIV style="MARGIN: 0px">leads me to believe it's not a module failure.</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">To make things more fun, the modules were installed
at two different</DIV>
<DIV style="MARGIN: 0px">orientations. One string is at 38d slope, 30d east of
true south,</DIV>
<DIV style="MARGIN: 0px">while the other two are at 36d slope, 75k east of
true south. This</DIV>
<DIV style="MARGIN: 0px">certainly has a detrimental impact on the
performance, but it doesn't</DIV>
<DIV style="MARGIN: 0px">seem to me that it could account for all of that
energy loss.</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Thoughts?</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Thanks a lot!</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">Dana</DIV>
<DIV style="MIN-HEIGHT: 14px; MARGIN: 0px"><BR></DIV>
<DIV style="MARGIN: 0px">--</DIV>
<DIV style="MARGIN: 0px">Dana Brandt</DIV>
<DIV style="MARGIN: 0px">Ecotech Energy Systems, LLC<SPAN
class=171392803-12092008> </SPAN></DIV></BLOCKQUOTE></DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008></SPAN> </DIV>
<BLOCKQUOTE type="cite"><SPAN class=171392803-12092008><SPAN
lang=EN> </BLOCKQUOTE>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008>[5/19/01]</SPAN><SPAN
class=171392803-12092008><SPAN lang=EN></DIV>
<DIV>"Brand X" has been taking a lot of arrows lately, some in jest and
some</DIV>
<DIV>deserved. I can't believe that Xantrex is trying to help Advanced
Energy</DIV>
<DIV>Systems and SMA gain market share, but it sure looks that way. A
little</DIV>
<DIV>history and an important question.</DIV>
<DIV>First, the ST2500 becomes the hottest thing in PV since the SW.</DIV>
<DIV>Next, ST2500 demand exceeds production.</DIV>
<DIV>Next, ST2500 has software problems.</DIV>
<DIV>Next, Xantrex is "experiencing a shortage of vendor supplied parts"
and</DIV>
<DIV>shipments stop.</DIV>
<DIV>Next, Xantrex tries to get us to switch to the derated ST2000-CB.</DIV>
<DIV>Then, Xantrex announces the XR2500 at $2759 with nearly the same specs
as</DIV>
<DIV>the $2500 ST2500.</DIV>
<DIV>Meanwhile, we are told ST2500 inverters are still being produced and
to</DIV>
<DIV>continue to take customer orders.</DIV>
<DIV>However, I am waiting for ST2500 inverters that I ordered since April
4.</DIV>
<DIV>(How long are you back-ordered without ship dates?)</DIV>
<DIV>And now we are told that the XR2500 "will be available for delivery by
July</DIV>
<DIV>1."</DIV>
<DIV style="MARGIN: 0px"></SPAN><SPAN
class=171392803-12092008>Joel Davidson</SPAN> </SPAN></DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008></SPAN><SPAN
class=171392803-12092008></SPAN> </DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008> </SPAN>><SPAN
class=171392803-12092008> [2/14/01]: </SPAN></DIV>
<DIV style="MARGIN: 0px">>The ST normally tracks the solar irradiance fairly
accurately, when a cloud</DIV>
<DIV style="MARGIN: 0px">>passes over the output drops proportionally. The
LCD meter is powered solely</DIV>
<DIV style="MARGIN: 0px">>from the array output, no AC backup power. The ST
will disconnect from the</DIV>
<DIV style="MARGIN: 0px">>grid if the grid voltage goes out of the window of
acceptance. UL 1741</DIV>
<DIV style="MARGIN: 0px">>requires a 5 minute timeout before
reconnecting.</DIV>
<DIV style="MARGIN: 0px">>The cooling fan comes on at about 200 watts of
output; it is controlled by</DIV>
<DIV style="MARGIN: 0px">>output, not thermally controlled. (This may change
with future versions of</DIV>
<DIV style="MARGIN: 0px">>the ST.)</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">>Here is the situation with the dealer's system.
There are two 2300-watt</DIV>
<DIV style="MARGIN: 0px">>arrays with an ST2500 for each array. To date, the
ST as generated up about</DIV>
<DIV style="MARGIN: 0px">>1,800 watts of output from each array. The LCD
indicates that the ST</DIV>
<DIV style="MARGIN: 0px">>intermittently cycles OFF-ON at around 600-700 watt
output level. The unit</DIV>
<DIV style="MARGIN: 0px">>does come back on. It appears that the LCD can,
under some circumstances,</DIV>
<DIV style="MARGIN: 0px">>"lock-up". During the lock-up the LCD only displays
"Rev 3". So far Trace</DIV>
<DIV style="MARGIN: 0px">>has not been able to recreate this "lock-up" even
with a unit that suffered</DIV>
<DIV style="MARGIN: 0px">>from intermittent lock-up in the field. Trace is
still studying the problem.</DIV>
<DIV style="MARGIN: 0px">>Perhaps there are some sensitivities to
installation environments, like</DIV>
<DIV style="MARGIN: 0px">>inductive coupling to a parallel high voltage line
at the site.</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">> >From conversations with the Trace engineers,
the occasional, intermittent</DIV>
<DIV style="MARGIN: 0px">>cycling seems to be caused by the ST's MPPT
algorithm being a little too</DIV>
<DIV style="MARGIN: 0px">>aggressive in tracking the mpp on the knee of the
IV curve. It appears that</DIV>
<DIV style="MARGIN: 0px">>with certain modules, under certain conditions, the
algorithm can over-shoot</DIV>
<DIV style="MARGIN: 0px">>the knee of the curve. Trace is actively studying
any occurrences of this</DIV>
<DIV style="MARGIN: 0px">>problem. If and when a new algorithm is released,
it will be field</DIV>
<DIV style="MARGIN: 0px">>upgradable with a single replaceable chip.</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">>The Trace engineers have been very helpful and
responsive with this</DIV>
<DIV style="MARGIN: 0px">>situation. They are very willing to help with any
problem ST installations.</DIV>
<DIV style="MARGIN: 0px">>They both want help get the system running and they
are learning about</DIV>
<DIV style="MARGIN: 0px">>unexpected glitches and quirks that can occur with
any new product release.</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">>Several dealers have asked my opinion about the ST
inverters. I advise them</DIV>
<DIV style="MARGIN: 0px">>the ST (Rev.1) like any other first release
product, is very likely to have</DIV>
<DIV style="MARGIN: 0px">>some quirks and problems that occasionally show up.
If I were to</DIV>
<DIV style="MARGIN: 0px">>sell/install any newly released, Rev.1 product, I
would advise the customer</DIV>
<DIV style="MARGIN: 0px">>that "the product is a first generation product and
there may be some</DIV>
<DIV style="MARGIN: 0px">>unexpected quirks. That both I (the dealer) and the
factory will stand</DIV>
<DIV style="MARGIN: 0px">>behind the product and will work to resolve any
problems that might occur."</DIV>
<DIV style="MARGIN: 0px">>If the customer (or you as the dealer) are not
comfortable with that</DIV>
<DIV style="MARGIN: 0px">>arrangement and understanding, then they should
either choose another</DIV>
<DIV style="MARGIN: 0px">>produce or wait until the new product has proven
itself in the field</DIV>
<DIV style="MARGIN: 0px">>(perhaps with a few up-grades or expanded
installation guidelines).</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">>I hope this helps shed some light on the current
situation with the ST</DIV>
<DIV style="MARGIN: 0px">>inverters. If any of you dealers are having
problems with STs that you've</DIV>
<DIV style="MARGIN: 0px">>installed and your distributor can not help to work
with Trace, please</DIV>
<DIV style="MARGIN: 0px">>contact me and I will see what I can do to
help.</DIV>
<DIV style="MARGIN: 0px">></DIV>
<DIV style="MARGIN: 0px">>Sincerely,</DIV>
<DIV style="MARGIN: 0px">>Steve Bell</DIV>
<DIV style="MARGIN: 0px">>SunWize Technologies</DIV>
<DIV style="MARGIN: 0px"></SPAN> <SPAN
class=171392803-12092008> </SPAN></DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008><FONT
face=Arial>[2/9/01]</FONT> </SPAN></DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008></SPAN>According to
well-informed sources, there is pressure being put on Trace to <BR>pull them
from the market until they work out the bugs on the MPPTracking. <BR>I
don't know about you all, but reading reports of a 2200 watt system under
<BR>full sun putting out all of 800 or so watts is rather disturbing. With
the <BR>grid-tie market going crazy in CA., it would give the industry and real
<BR>black eye if battery-less ST systems were putting out a fraction of the
<BR>appropriate output.<FONT lang=0 face=Arial FAMILY="SANSSERIF"> <BR>Marco
Mangelsdorf</FONT></DIV>
<DIV style="MARGIN: 0px"><FONT face=Arial></FONT> </DIV>
<DIV style="MARGIN: 0px"><SPAN class=171392803-12092008><FONT
face=Arial>[2/7/01]</FONT></SPAN><SPAN lang=EN></DIV>
<DIV>I just got off the phone with John, our dealer (he is competent) ;
here</DIV>
<DIV>is what he says.</DIV>
<DIV>He has two ST-based systems operating; one is a single ST2500 with
1,000</DIV>
<DIV>watts of Arco modules, the other is system has two ST-2500s and about
2,200</DIV>
<DIV>watts of UniSolar modules per ST.</DIV>
<DIV>Both systems seem to be acting the same way. Multiple times during the
day</DIV>
<DIV>the ST will power up to about 650 to 700 watts and then cycle off.
Many</DIV>
<DIV>times the LCD display goes dim or shuts off and the Total Daily
Watt-Hour</DIV>
<DIV>reading on the LCD re-zeros when it cycles down. The units do come back
on</DIV>
<DIV>after a short while. This happens many times during the day.</DIV>
<DIV>Although he does not have exact monitored data, it seemed that the
power</DIV>
<DIV>output of the ST is well below expected. On a sunny day with 2,200 watts
of</DIV>
<DIV>UniSolar the ST was indicating less than 800 watt-hours of output.</DIV>
<DIV>The cooling fan comes on whenever the ST output climbs above about
200</DIV>
<DIV>watts.</DIV>
<DIV>John talked to Dean at Trace about the problems he is having. Dean says
that</DIV>
<DIV>the ST may cycle off and on several times in the morning and then</DIV>
<DIV>occasionally (two-three times) during the day. John reports that the
cycling</DIV>
<DIV>is much more frequent throughout the day.</DIV>
<DIV>Dean says that the ST may be too aggressive in its power tracking and
they</DIV>
<DIV>(Trace) may need to adjust it's aggressiveness. The fan operating
anytime</DIV>
<DIV>the ST output is over 200 watts is supposed to be some code or
regulatory</DIV>
<DIV>requirement. (It seems like it should only operate when the ST is
warm.)</DIV>
<DIV>Because the ST sometimes losses the daily watt-hour total on the LCD when
it</DIV>
<DIV>cycles, it sounds like the unit is totally cycling down during it's
many</DIV>
<DIV>daily cyclings. (The LCD also shuts off and clears the WHr total
every</DIV>
<DIV>night.) It sounds like Trace may need to supply a replacement chip to
fix</DIV>
<DIV>this cycling problem. It also sounds like some independent measurements
of</DIV>
<DIV>ST output v.s. array input may be well advised.</DIV>
<DIV>In fairness to Trace, this is their Ver.1 of the ST. Hopefully they will
fix</DIV>
<DIV>the problems quickly. Remember the Ver.1 SW-series had problems too.</DIV>
<DIV>I hope this explaination makes sense. Thanks for all the feed-back so
far.</DIV>
<DIV>Any other experiences with the ST are welcome.</DIV>
<DIV>Steve Bell</DIV>
<DIV>SunWize Technologies</DIV>
<DIV style="MARGIN: 0px"></SPAN></SPAN> </DIV>
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