25 kW inverter [RE-wrenches]

[Kirpal Khalsa]

Matt.....Paul....Thanks for your helpful responses....makes perfect sense.......
Cheers,
Kirpal

On Mon, Jun 16, 2008 at 10:25 AM, Matt Lafferty
<mlafferty at universalenergies.com> wrote:
>
> Sunshine Wishes to all Wrenches,
>
> RE:  Oregon LRET limited to 25 kVA.
> http://licenseinfo.oregon.gov/index.cfm?fuseaction=license_seng&link_item_id
> =1684
>
> Matt's Perspective:
> For Inverter based PV systems, the answer is simple:  Sum of Inverter
> Maximum Power ratings.
> For non-inverter based PV systems, there is no reactive power, and therefore
> there isn't a kVA rating... Oooops!  <Would somebody please run over the the
> CCB and close that door?>
>
> Paul Israel has the correct answer.  More importantly, he has the right line
> of thinking for his answer.  The responisible line of thinking.  Bravo to
> Paul!
>
> This is a Contractors' License issue.  There is a reason for it, whether or
> not you agree with the reason(s).  If you want to work on systems that have
> kVA ratings larger than the limit, get the appropriate license or wait until
> the limit changes upward to a rating more to your liking. (In the meantime,
> you could submit a motion to modify the classification...)
>
> Think about it this way:  It is not reasonable to require a Contractors'
> License board in one state to base the kVA limits of a given classification
> on some ever-changing incentive-program methodology that is based and
> maintained in and by another state and may be subject to withdrawal at some
> time in the future.  To think otherwise is foolish.
>
> I can hear the sand in the gears now as some poor clerk at the OR CCB tries
> to answer this question... "OK. Let's see here... The classification limits
> work to 25 kVA. (Fact)  You want to calculate this based on this PTC
> (non-nameplate) value from this website here then multiply by some
> efficiency number from this website here then by the number of inverters
> then by the number of modules which gets you to some # of WATTS. Is WATTS
> the same as kVA?  I'll have to get back to you."
>
> <NOTE>  If this methodology has not yet been defined at the OR CCB, I hope
> that one or more of our mature Oregon bretheren will take it upon themselves
> to gently submit this recommended definition:  kVA shall have the same
> meaning as 1,000 Volt-amperes, or 1,000 watts, or 1 kilowatt. RE systems
> utilizing inverters shall have their kVA ratings calculated based on the Sum
> of the Maximum Power Output ratings of the inverter(s). RE systems that
> utilize direct current only shall have their ratings calculated based on the
> Sum of the Maximum Power ratings of the PV modules (panels).
>
> If you are one of the 15 LRET's and want to push the envelope, do so at the
> peril of many, not just yourself. The 25 kVA limit was negotiated.  Some of
> the contractors on the "other side" of 25 kVA are most likely to be watching
> for just this thing.  In Oregon's case, it will be relatively easy to track
> down via Rebate Program statistics.  Much blood over "classification" has
> been shed in CA. Unnecessary blood in my opinion, but this industry did not
> move proactively in time to avoid it. I'm hearing the early sounds of a
> 3-years-later echo coming from OR here...
>
> Welcome to rebates!  Please don't be greedy!
>
> Be thankful that Oregon has a Limited Renewable Energy Technician
> classification that allows non-Electrical Contractors to even do this work
> and that it isn't limited to 10 KW.  Many states don't.  Bravo Oregon!
>
> Peace and Sunshine! See you all at Country Fair.
>
> Matt Lafferty
>
> -----Original Message-----
> From: Paul Israel
> Sent: Thursday, June 12, 2008 1:18 PM
> To: RE-wrenches at topica.com
> Subject: RE: 25 kW inverter [RE-wrenches]
>
>
> Wrenches,
>
> 1.  Most Utility Interconnection Applications use the inverter nameplate to
> determine system size for interconnection.
>
> 2.  The NEC uses it to size the OCPD.
>
> 3.  The manufacturers vary as to which inverter can handle power above the
> nameplate rating.  Some will process the extra power others will not.
> However, by the time we follow the manufacturers or figure for ourselves how
> much wattage the inverter can efficiently process we are probably darn close
> to the rated nameplate.  Time, that stringent beast, will limit it anyway.
>
> 4.  Oversizing an inverter for future expansion would limit us to installing
> a 25kW inverter.  Installing a 50kW inverter and then putting 25kW of panels
> would be questionable at best.  A loophole that would be quickly closed.
>
> Hey, let's just change the law!
>
>
>
>
> Paul N. Israel, President
>
>
> - - - -
> Hosted by Home Power magazine
>
> To send a message: RE-wrenches at topica.com
>
> Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read
>
> List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php
>
> Check out participant bios: www.mrsharkey.com/wrenches/
>
> Moderator: michael.welch at homepower.com
>
>
>



-- 
Sunny Regards,
Kirpal Khalsa
NABCEP Certified Solar PV Installer TM
Renewable Energy Systems


- - - -
Hosted by Home Power magazine

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

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

List rules & how to change your email address: www.mrsharkey.com/wrenches/etiquette.php

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

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at re-wrenches.org

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

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------