William, 

Congratulations on an elegant solution and thanks for following up. 
It's always of great interest to hear how these things work out.

I know some AHJs can be obstructive or difficult to work with, but IMHO 
the vast majority are more than willing to work with you, to arrive at a 
good design and installation, if they are approached with a positive attitude.

I know you know all this, but there may be some reading who don't, who 
may unfortunately consider the inspector an adversary.

It bears repeating that the NEC is not always user friendly. Even
experts in the trade will encounter sections with which they have no experience.
In these situations the Code Handbook can often be of value to shed light
on the question. It is very expensive, but older editions are available
from any number of sources at much less cost. They will not contain the latest
code on 
Article 690, but will frequently help with issues such as yours, which have been
addressed
now for many code cycles. 

Dick
Solarwind Electric 

 

--- You wrote:
Dick:

Just to follow up, below is the reply I received from the inspector when I 
asked for clarification.  I had asked for clarification because I admit 
ignorance to this section and I wanted to formulate a good response on the 
first attempt:

There must be a main disconnect for panel C in the pump house. A main
circuit breaker in panel C would satisfy this requirement. If the panel
does not have a main circuit breaker (MLO) a maximum of six branch circuits
are allowed per NEC 225.33.

I prefer to approach these requirements with generic solutions.  The 
broader a solution, the more likely it will apply to other projects.  Also, 
a generic solution can box you in to a certain design.  I did not know the 
number of circuit breakers and did not want to drive out to the job to find 
out.  Instead I put this note on the plans:

4. Panel C shall have 6 or fewer circuit breakers or implement Documented 
Safe Switching Procedures per 225.32 Exception 1.

This proved to be acceptable and a permit was issued a few days ago.  I 
have since found out that there are 5 existing breakers.  One is in the off 
position and may be a spare.  We will be installing two inverters, bringing 
the number of breakers to 7.  If I can remove one breaker, I achieve 
compliance that way. If I can not remove a breaker, I write up a procedure, 
post it and I'm good.

Thanks for your input.

William Miller



At 06:33 PM 12/11/2009, you wrote:
>William,
>
>No, I mean what is your problem with complying with the request, "Show the
>number of existing circuits and/or the
>disconnecting means for panel C". Why not just do that?
>
>Dick
>
>
>
>--- You wrote:
>Dick:
>
>I too am mystifed.  I sent a request for clarification but have not
>heard back.  It may be some kind of power trip as we have been at odds
>over many issues.  I will report back.
>
>William Miller
>Millersolar.com
>
>On Dec 11, 2009, at 6:05 PM, Richard.L.Ratico@VALLEY.NET (Richard L
>Ratico) wrote:
>
> > William,
> >
> > No direct specific experience with this, but, respectfully, what is
> > the problem?
> > The code sections seem clear and not unreasonable nor arduous.
> >
> > Dick Ratico
> > Solarwind Electric
> >
> >
> > --- You wrote:
> > Friends:
> >
> >
> > I just received a plan correction for a grid-tie permit application
> > wherein
> > the inspector is questioning compliance with section 225.  Below is
> > the
> > text of the correction notice:
> >
> > The existing panel C in the pump house must comply with NEC 225.31. 225.32
> > & 225.33. Show the number of existing circuits and/or the
> > disconnecting
> > means for panel C.
> >
> > Has anyone ever had experience with this section being applied to a
> > grid-tie system?  The inverters will be inside a pump house remote
> > from the
> > main residence.
> >
> > Thanks in advance.
> >
> > William Miller
> >
--- end of quote ---

