Inverters islanding in L.A. [RE-wrenches]

[Matt Lafferty]

Joel:

I'm sorry for the misunderstanding.  I didn't know that you only
participated in the Solec Installations up here.  I was, for whatever
reason,
under the impression you were involved with other Project Years.  The Solec
Installations used the Omnion 2400 series Inverter.  An inverter that I'm
sorry to say is no longer available.  Please forgive me for that one.

Joel writes:

> Matt, Let's get the facts in the open.
> 1) I have never installed an inverter that was reported to have
> islanded.
> 2) Placer Electric and Johanson have installed over 250 grid-tied PV
> systems under contract for me when I was with Solec. None were reported
> to have islanded.
> 3) What dates did the grid go down and islanding occur?
> 4) I forgot to list question #4, but you are welcome to answer it.

My reply:

1)  Anyone who has installed a Trace SW 4048 or SW 5548 UPV or PV series
(These are NOT the PV-XX208 inverters)
grid-tied only inverter has installed an inverter capable of islanding.
(See note below)  Unless there is a failure within the equipment, it will
produce AC power in a no-load loss of grid situation.  I
don't know if this is one of UL's tests or not but this is the situation I
understand to have led to the current situation in LA.  Please read further.

2)  To my knowledge, #1 applies to both Placer Electric and Greg Johannsen
(At least that's the way I have his name spelled. Please correct me if I'm
wrong.)  Whether or not they were reported to have islanded, doesn't mean
they won't, can't or haven't.  My personal experience didn't lead to an
official "Islanding Report".

3)  I don't have "grid down and reported islanding associated with it data"
available.  There may never have been a "reported" islanding condition
associated with this inverter.  My reference to my witnessing this condition
previously was during three service calls to Customer homes; the first was
January or February 2001, a Johannsen installation by the way, the second
was November 2001, the third was December 2001.  I basically raised an
eybrow at the first, started thinking about the possible implications (like
what we are seeing in LA) at the second and decided that I should notify,
and did, those above me of my concerns after the third.  (I know what you
all are thinking....NO!  I had absolutely nothing to do
with the CEC or UL actions taken.  In fact, it was my opinion, which I still
believe was valid, that we should look at the potential situation and
implement corrective action, if necessary, and keep it private to avoid the
same type of situation we are seeing in LA happen here.  At that time I had
no idea that these inverters were ever even installed anywhere else.)

4)  Let me go look at what question 4 was.  Oh yeah.  That depends on what
you call an "island".  The conditions I have seen were at "no load", PV
breaker "Off", Voltage on the back of it.  It is my understanding that this
is exactly what was witnessed in LA and kinda got all this started.  As I
said above in #3, I could see somebody finding this out, possibly the hard
way, and it becoming a significant issue.

I really didn't want to have to go this deep, since it could fall into
"unfriendly hands", but it is an issue.  I began writing about one of my
experiences with this but decided to not include it, for the "unfriendlies"
issue.  I will send it to those of you who write me off-list.  Joel, I'll
send it to you, whether or not you write me off list... ;-)

In closing, I want to make a couple of things clear:

1) Safety has to be considered and provided for at all times.

2) Based on our testing, we don't believe that the SW issue is a risk to
linemen, under all but the most unusual circumstances.

3) My intent is not to "Flame" anybody, Wrench, Manufacturer....Well, maybe
the Union, and politics in general, but that's another post.

4) I LOVE what I do.  I want to share, the good and the bad so mistakes
don't have to be repeated and we can all benefit from the gift of Sunshine.

5) I don't have all the answers, never will.  I am not perfect, never will
be.  I can only strive for excellence and maintain integrity.

6) The nature of what we do, combined with the fact that PV has "come to
town", means that the industry is in the limelight, as a whole.  Not
everybody is supportive of what we do.  If we are going to stay in town, we
need to work within established rules.  If the rules are fundamentally
wrong, then we need to work to modify them, in a manner that the "powers
that be" can be comfortable with.  These processes take time.  We need to
realize that.

Best to all and. . . .

Pray for Sun!

-Matt Lafferty
pvpro at attbi.com

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://www.topica.com/lists/RE-wrenches/

List rules & etiquette: http://www.mrsharkey.com/wrenches/etiquete.htm

Check out participant bios: www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com

==^================================================================
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9
Or send an email to: RE-wrenches-unsubscribe at topica.com

T O P I C A -- Register now to manage your mail!
http://www.topica.com/partner/tag02/register
==^================================================================