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<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial>One weakness did present itself to me during my installation
of Enphase inverters. Enphase makes some hay with the "no single point of
failure" topology.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial>However, all the individual inverters share common AC buss
wires. These are built by daisy chaining AC leads from inverter to inverter
and then to the branch circuit.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial>The weakness is that if any single AC Tyco connector
connection fails, all inverters upstream of that connector will be
effected. Sort of gets you back to the weakness of module to module
connections in a string system. </FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial>Interesting to me that we can talk much about the life cycle
testing of the inverter, but in this case it all comes back to a connector
to connector connection.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009><FONT color=#0000ff
size=2 face=Arial>So a real question becomes, how will the Tyco connectors hold
up over time in real world applications.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=140562221-08112009></SPAN> <BR><SPAN
lang=en-us><FONT size=2 face=Arial>Mark Frye</FONT></SPAN> <BR><SPAN
lang=en-us><FONT size=2 face=Arial>Berkeley Solar Electric Systems</FONT></SPAN>
<BR><SPAN lang=en-us><FONT size=2 face=Arial>303 Redbud Way</FONT></SPAN>
<BR><SPAN lang=en-us><FONT size=2 face=Arial>Nevada City, CA
95959</FONT></SPAN> <BR><SPAN lang=en-us><FONT size=2 face=Arial>(530)
401-8024</FONT></SPAN> <BR><SPAN lang=en-us></SPAN><A
href="http://www.berkeleysolar.com/"><SPAN lang=en-us><U><FONT color=#0000ff
size=2 face=Arial>www.berkeleysolar.com</FONT></U></SPAN></A><SPAN
lang=en-us><FONT size=2 face=Arial> </FONT></SPAN> </DIV>
<DIV> </DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <B>On Behalf Of </B>Nick
Soleil<BR><B>Sent:</B> Sunday, November 08, 2009 12:19 PM<BR><B>To:</B>
RE-wrenches<BR><B>Subject:</B> Re: [RE-wrenches] Enphase track
record<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV style="FONT-FAMILY: arial,helvetica,sans-serif; FONT-SIZE: 12pt">Hello
wrenches:<BR> Enphase is an excellent, reliable product, with
many advantages, but a few minor bugs. I have managed many Enphase
installations, have been involved in Beta Tests with them, toured the facility,
and I have attended customer feedback sessions with them. I will give you
a quick overview:<BR> - Being able to
monitor individual module output is priceless. Antony's experience is
valid, his problem was related to the bad module. When I do system
testing, I will frequently find module issues related to a failed string of
cells, on one modules. I think this is a common problem, which is rarely
found.<BR> - The inverters are very
reliable. I have never had a failure on an Enphase Inverter or
Monitor. At Enphase, here in Petaluma, they place the inverters in
life-cycle testing beds, which apply continuous 160 degree temperatures to the
units, while placed on a vibrating plate. <BR>
- I had an inverter communication error once, and called
Enphase, they connected to the monitor and uploaded the softare to it remotely,
and resolved the issue.<BR> - The
monitoring system and Enphase web-based monitoring system is easy to work
with. Enphase does all the work to set it up for you!
<BR> - Availability has been extremely
tight since late April. They really blew it when they discontinued the 175
watt inverter, and ended up not having any replacement for months. By
then, they were really back-ordered.<BR> -
They hired a few of the guys who made the technical support at SMA so great
(Kent Sheldon, Marv Dargatz, and others.) <BR>
- The biggest issue with using Enphase is that communication
errors will occur between the modules and inverters. Most of the time it
is fine, and the inverters will continue to produce power, but the monitor will
lose connection with 1 or more inverters, and the website will post 0 watts
output for those modules. Once the communications are restore, the daily
and monthly outputs will be corrected, but the graphs and time-lapse show will
be in-accurate. This can lead to some customer calls, but the customers
are normally accepting, because it is so impressive, it is easy to accept the
occasional glitch.<BR>
<DIV> </DIV>Nick Soleil<BR>Project Manager<BR>Advanced Alternative Energy
Solutions, LLC<BR>PO Box 657<BR>Petaluma, CA 94953<BR>Cell:
707-321-2937<BR>Office: 707-789-9537<BR>Fax: 707-769-9037
<DIV><BR></DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Nick Vida
<nickvida@ymail.com><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B>
wrenches <re-wrenches@lists.re-wrenches.org><BR><B><SPAN
style="FONT-WEIGHT: bold">Sent:</SPAN></B> Sat, November 7, 2009 6:04:40
PM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> [RE-wrenches]
Enphase track record<BR></FONT><BR>
<DIV style="FONT-FAMILY: times new roman,new york,times,serif; FONT-SIZE: 12pt">
<DIV><I></I><PRE><SPAN style="FONT-FAMILY: times new roman,new york,times,serif"><SPAN style="FONT-WEIGHT: bold"><BR></SPAN></SPAN>I<BR>That's interesting Drake, about the accessible groups. <BR>Are there clearance issues for thermal concerns or anything?<BR>It sounds like you could run your dc wires up the rows and have<BR>all your inverters grouped on the top rail. That a one man call to<BR>trouble shoot a system which has been a big concern from many voices <BR>all along. Maybe those guys can offer several whip lengths or something... <BR>i don't know I haven't worked with the gear yet.<BR><BR>nick vida<BR><BR> <BR>I'm also concerned about the issues brought up here. I have two <BR>possible projects that would benefit from Enphase due to the fact <BR>that the modules will go on more than one roof, with significantly <BR>different orientations. In one case, there are shading issues as well.<BR><BR>Supposedly the Enphase units are selling fast.
Someone<BR> must be <BR>installing them. They have been out long enough that there must be <BR>some data as to whether or not the units are surviving. The long <BR>term will not be known until the inverters have been out for many <BR>years, however if they are having issues in the short term, then we <BR>know they have issues.<BR><BR>One idea that Enphase tech support said was acceptable was to mount <BR>the inverters in accessible groups. The DC leads would need to be <BR>extended, and some loss would occur. Also the inverters can be <BR>mounted in vented attics. Having the inverters in a group in an <BR>accessible attic would make maintenance easier than tearing apart an <BR>array to get to a dead inverter.<BR><BR></PRE></DIV></DIV><BR></DIV></DIV><!-- cg12.c3.mail.sp2.yahoo.com compressed/chunked Sun Nov 8 11:30:58 PST 2009 --></DIV><BR></BODY></HTML>