[RE-wrenches] Tranformless inverter

[Exeltech]

Transformerless grid-tie inverters are permitted under the National Electric Code as of 2008.  The Nationally Recognized Testing Laboratories (UL, ETL/Intertek, CSA, etc.) took a while to develop the testing procedures for testing to UL1741, which was the basis for most of the delay.

SMA isn't the only company with transformerless grid-tie inverters.  I know of one American manufacturer with transformerless models on the market as well.

Transformerless inverters are smaller, much lighter, and tend to be more efficient than transformer-based units.  No transformer also means lower product cost, and less shipping expense.  Win-win-win.


Dan


--- On Fri, 10/1/10, Drake <drake.chamberlin at redwoodalliance.org> wrote:

From: Drake <drake.chamberlin at redwoodalliance.org>
Subject: Re: [RE-wrenches] Tranformless inverter
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Date: Friday, October 1, 2010, 6:58 AM


 
I also received this advertisement.  Previously I had investigated
the smaller SMA transformerless inverters, and was told that this type
would not be allowed in the US until the 2011 code.  Has the ban
been lifted?





At 12:52 AM 9/29/2010, you wrote:

Wrenches:


I received an advertisement from a distributor that SMA is now shipping
8, 9 and 10 KW transformerless inverters.  Don't these require
double insulated PV wiring and no connection  to ground on the AC
side? It's been too long since this subject last crossed my desk and I
want to refresh my memory on the specifics.


William Miller




Please note new e-mail address and domain:


William Miller 

Miller Solar

Voice :805-438-5600

email: william at millersolar.com


http://millersolar.com

License No. C-10-773985



      
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