[RE-wrenches] Point of connection question

[Ray Walters]

HI William;

I think you might have a problem.  Looking at Enphase's ratings, the 
M190 has an output rating of 800mA, while the M250 has an output rating 
of 1.0 A.  10 M250s = 10 amps, 9 M190s = 7.2 amps
17.2 amps exceeds 80% of your 20 amp breaker.
I know this won't actually happen, but my understanding is that 690.8 
(A)(3) dictated how to figure this, and 690.8(B)(1) dictates the 80% of 
breaker rating.  So I think code wise, you're out of luck, unless you 
have a 100% duty rated breaker and load center.

My thinking is that most inspectors would give you a pass; especially 
when you show them the actual current flowing with the smaller modules.  
Can you put more modules per inverter, or otherwise drop a couple of 
inverters?

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 10/9/2013 4:06 PM, William Miller wrote:
>
> Friends:
>
> At the risk of asking a question that may have been asked and answered 
> here in the past, I wish to pose a question about Point of Connection.
>
> Rather than outline the situation here I put it all on a web page. If 
> any of you have a moment to review this, I would be most appreciative.
>
> http://www.millersolar.com/MillerSolar/case_studies/POC/_POC_Question.html
>
> Thanks in advance,
>
> William Miller
>
>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20131009/e00f7d94/attachment-0004.html>