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<div class="moz-cite-prefix">The <a
href="http://www.aclaratech.com">Aclara</a> <a
href="http://www.aclaratech.com/AclaraPLS/pages/default.aspx">TWACS</a>
signal that knocks the Enphase inverters off line is difficult to
capture because it only last a few seconds every time the meter
replies to a ping or data request. I did manage to capture it
using <a href="http://www.zelscope.com/">Zelscope</a> with a long
recording time. The attached image shows a pulse at the zero
crossing of the ac waveform; some crossings don't have a pulse -
I think that is a binary zero and the pulse represents a one. The
pulse does not change the ac frequency and has only a negligible
effect on the rms ac voltage. However, the time between zero
crossings is not always 16.67 ms.<br>
<br>
Messing with the zero crossing like that is an ugly thing to do to
the ac voltage. Many things other than inverters can be messed up
by this. It caused one of my digital clocks to run fast. Our local
utility has had complaints about numerous other devices that it
has messed up. I've got some SunnyBoy systems with remote
monitoring that don't seem to be bothered by this signal. The
Enphase inverters do not tolerate it. I'm glad to hear that
Enphase is working on a fix and hope that it is rolled out soon.<br>
<pre class="moz-signature" cols="72">Kent Osterberg
Blue Mountain Solar, Inc.
<a class="moz-txt-link-abbreviated" href="http://www.bluemountainsolar.com">www.bluemountainsolar.com</a>
</pre>
On 2/5/2013 2:38 PM, Nick Soleil wrote:<br>
</div>
<blockquote
cite="mid:CAAV1814uAtEf5dwTpbHgTwfuTwdt_F7ri=z75wsWjjGVgXfG0A@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>
<div>
<div>Hi wrenches,<br>
<br>
The frequency out of range issue is being caused by some
utility meter's communication "ping". This ping is
actually affecting the utility voltage and frequency, and
can be viewed with a power quality analyzer. It is highly
likely that this is affecting a wide variety of
utility-interactive inverters, but is only noticeable with
the Enphase systems; due to the high level of visibility
that our Enlighten monitoring and reporting provides.<br>
</div>
<div><br>
</div>
</div>
These changes required that the software undergo a new
certification process. We have completed our CSA certification
of the new software, and are validating it's functionality
before pushing out the solution to our entire population of
microinverters. We are in the process of beta testing the
software fix, and are hoping to have this resolved in
February.<br>
<br>
</div>
Thank you for your patience as we work to resolve this issue.</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Tue, Feb 5, 2013 at 9:24 AM, <span
dir="ltr"><<a moz-do-not-send="true"
href="mailto:penobscotsolar@midmaine.com" target="_blank">penobscotsolar@midmaine.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Dave,<br>
It doesn't happen often, and the longest I've seen him
stay "down" is<br>
about a half hour, but it seems to get progressively worse
as time goes<br>
on for some reason (initially only the five minutes, but
longer down<br>
times lately). This particular customer is difficult and
picky, to<br>
boot. I hope yours is a bit kinder. Mine seems to think we
did him an<br>
injustice of monumental proportions.<br>
We have had the utility out there logging events,
meetings with the<br>
utility and another solar company in Maine to discuss all
this, and<br>
have kept Enphase in the loop throughout. Enphase has
responded in a<br>
responsible and reasonable manner throughout.<br>
If you want to discuss this with Enphase, call and ask
for Bret. He's<br>
the engineer I previously dealt with, although he is second
tier, he is<br>
accessible.<br>
<div class="HOEnZb">
<div class="h5"><br>
<br>
<br>
<br>
> Thanks Daryl. Does your system also sometimes stay
off for longer periods<br>
> sometimes? My clients system can stay off for up to
64 minutes.<br>
><br>
> Dave<br>
><br>
> -----Original Message-----<br>
> From: <a moz-do-not-send="true"
href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a><br>
> [mailto:<a moz-do-not-send="true"
href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>]
On Behalf Of<br>
> <a moz-do-not-send="true"
href="mailto:penobscotsolar@midmaine.com">penobscotsolar@midmaine.com</a><br>
> Sent: Tuesday, February 05, 2013 12:01 PM<br>
> To: RE-wrenches<br>
> Subject: Re: [RE-wrenches] Enphase "AC Frequency
out of Range"<br>
><br>
> Dave,<br>
> We have been having the same problem with an
Enphase system in Maine. I<br>
> have been dealing directly with the third tier
engineers at Enphase and<br>
> they<br>
> are working on a software fix for this. The"event"
itself is only a<br>
> fraction<br>
> of a second but IEEE requirements are that the
inverter shut down for five<br>
> minutes. I only found out about this problem when
it started for this<br>
> customer. It sems that Enphase has already
addressed the problem with a<br>
> software fix for the M-190's. The M-215 fix should
come, according to<br>
> Enphase, by the end of March. It will be
automatically downloaded through<br>
> the Enlighten router.<br>
> It's a known issue with Smart Meters with
Enphase, but should be<br>
> reconciled soon.<br>
><br>
> Daryl DeJoy<br>
> NABCEP Certified PV installer<br>
> Penobscot Solar Design<br>
> <a moz-do-not-send="true"
href="http://www.penobscotsolar.com" target="_blank">www.penobscotsolar.com</a><br>
><br>
><br>
><br>
>> Wrenchsters,<br>
>><br>
>><br>
>><br>
>> I have an Enphase 7.5kW system on a residence
with utility Smart<br>
>> Metering, both the PV Production Meter as well
as the utility billing<br>
>> meter being "read" every hour. This system has
experienced many "AC<br>
>> Frequency Out Of Range" events since the system
was installed. Below<br>
>> is copied the Enphase Event message. This
particular event was for 5<br>
>> minutes. Most of the events (all events are AC
Frequency Out Of Range)<br>
>> last 5 to 10 minutes but occasionally they have
lasted from 45 minutes<br>
>> to<br>
> 64 minutes.<br>
>><br>
>><br>
>><br>
>> My question is: Could the use of the smart
metering increase the<br>
>> likely hood that AC Frequency events happen? Or
is this just a<br>
>> coincidence and that we are dealing with
fluctuating utility power AC<br>
>> Frequency issues?<br>
>><br>
>><br>
>><br>
>> <<<br>
>><br>
>><br>
>><br>
>> Started on: Mon February 04, 2013 12:49 PM EST<br>
>><br>
>> Cleared on: Mon February 04, 2013 12:54 PM EST<br>
>><br>
>><br>
>><br>
>> Recommended action<br>
>><br>
>><br>
>><br>
>> This condition should correct itself. No action
is required.<br>
>><br>
>> Details<br>
>><br>
>><br>
>><br>
>> The microinverter reports that the frequency
coming from the utility<br>
>> is either too low or too high as specified by
applicable regional<br>
> standards.<br>
>><br>
>><br>
>><br>
>> AC frequency is the frequency at which voltage
varies on the utility<br>
>> grid.<br>
>> Frequency Out of Range events are usually
transient and<br>
>> self-correcting by the utility.<br>
>><br>
>><br>
>><br>
>> When the microinverter detects an out of
frequency condition, it must<br>
>> remain offline until the utility has been
within acceptable limits<br>
>> continuously for a short period of time
(seconds to minutes, varies by<br>
>> region). If during that time the utility again
exceeds or falls short<br>
>> of acceptable limits, the five-minute timer
must restart and the<br>
>> microinverter may not begin producing power for
an additional short<br>
>> period following the last out-of-bounds
condition. >><br>
>><br>
>><br>
>><br>
>> Best,<br>
>><br>
>> Dave<br>
>><br>
>><br>
>><br>
>><br>
>><br>
>> David Palumbo<br>
>><br>
>> Independent Power LLC<br>
>><br>
>> 462 Solar Way Drive<br>
>><br>
>> Hyde Park, VT 05655<br>
>><br>
>> <a moz-do-not-send="true"
href="http://www.independentpowerllc.com"
target="_blank">www.independentpowerllc.com</a><br>
>><br>
>> Vermont Solar Partner<br>
>><br>
>> 25 Years Experience, <a moz-do-not-send="true"
href="tel:%28802%29%20888-7194" value="+18028887194">(802)
888-7194</a><br>
>><br>
>><br>
>><br>
<br>
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