If I remember correctly, we worked through this in 2008. A supply side
connection is NOT considered a separate service. And, seven disconnects is one
more than six, and is NOT code compliant.

Dick Ratico
Solarwind Electric

--- You wrote:
I've made similar observations as Matt before about adding the seventh handle,
but... A supply-side connection is considered a separate service. Each service
is allowed six handles. If you take a panel like we're discussing here and add
in a backfed breaker to the top section, you have six disconnects for the first
service and one new disconnect for the second service. Seven disconnects in one
panel, but still Code compliant.

Thoughts?

Scott

On Nov 1, 2010, at 9:12 PM, Matt Lafferty wrote:

> Dana,
>  
> Connection anywhere "above" any of the six service disconnects is considered a
supply-side tap.  One problem with connecting there is that your new number of
service disconnects would be seven.
>  
> Connecting to the lower 100A bus fed with a 60A "main" is the most code
compliant in theory. The 60A is the main for the purposes of your installation.
The other side of the main is the utility. Whether the upper section has an
amperage rating or not is moot.
>  
> You still have to make a determination of suitability with regard to breakers,
age, condition, etc.
>  
> Cheers,
>  
> Matt Lafferty 
> From: re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] On Behalf Of Dana Brandt
> Sent: Monday, November 01, 2010 6:55 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] backfeeding "six disconnect" panel
> 
> Hi everyone,
> 
> I just noticed my last email didn't go through because I'd attached pictures
of the panel. If you're interested in the pics of the panel please contact me
off-list. 
> 
> Thanks for the feedback. To clarify, the upper part of the bus is lug-fed
directly from the service meter - no overcurrent protection. I have this same
situation in two homes - one has a Bryant panel, not sure about the other. 
> 
> It seems possible connecting to the top bus could be considered a supply side
connection. It's done through a panel bus, though, which seems like maybe it
wouldn't qualify.
> 
> It's true that the 60A breaker feeding the 100A bus fulfills the calculation
requirements. However, the calculation has to follow upstream to the bus
supplying that 60A breaker, so again we have a potential problem since there's
no overcurrent protection for that bus.
> 
> So, it seems the real question is about that top bus. Can we consider a
connection there a supply side tap? If not, who do we do the 690.64 (B) (2)
calculation without a main breaker? 
> 
> Thanks!
> 
> Dana
> 
> Dana Brandt
> Ecotech Energy Systems, LLC
> www.ecotechenergy.com
> dana@ecotechenergy.com
> 360.510.0433
> 
> 
> On Thu, Oct 28, 2010 at 6:37 PM, Matt Lafferty <gilligan06@gmail.com> wrote:
> Hi Dana,
>  
> "Sounds like" you have a lower-bus rated at 100A being fed by a 60A breaker...
Yes?
>  
> If so, technically speaking but not necessarily the right thing to do, you
have a SWEET SETUP! In 690.64 terms, you are legally allowed 120A to feed that
bus. Which converts to a maximum 60A PV interconnection breaker located at the
opposite end of the bus from the 60A supply breaker. This is a panel
configuration that I have wished was still made for many years.
>  
> The downside is... It's probably older than me. With really wimpy buses. And
really bad options for replacement breakers. And is full of 2-wire homerun
circuits.
>  
> If it doesn't have a perfect-in-every-way bus, it's time for a new panel. You
also need to be able to buy real... Modern.... And New UL Listed breakers. Those
gray looking replacement breakers in the home improvement store? They're NOT OK.
In any way.
>  
> Wadsworth? FPE? Bulldog? &...??? These panels are NOT OK for interconnection
at this point. Time to upgrade. Yes, really. Zinsco? Depends. Any panel with
signs of arcing around the bus anywhere? Better have a damned good explanation
before I'd be tying in some PV. I know of a couple. Warped breakers? Change it!
>  
> I just got done doing a 90% rewire on a friend's house and it tore my heart
out sending the panel to the recycler. (This friend is into long-term thinking
and sustainable everything. I would have left it if I could and so would they.)
The bus was pristine. It is rumored that Al Capone used to stay in this place
when he was in the area. The panel was giant, with lots of room. This panel had
a coolness factor off the charts. But... I couldn't reliably get trustworthy
breakers. And it was my friend's house. Somebody I care about. I couldn't leave
it in there. I use the same judgement whether my customer is a friend or not.
>  
> If what you have is a modern panel, share! I know I would personally
appreciate it if you were able to share mfr, model, pictures, etc. Whenever we
are upgrading/swapping/moving a service panel, we need to be installing
something that provides the best opportunity for interconnection of distributed
resources. We don't have those at this point. And we need them. A
split-distribution (not just split-bus) service panel is one way to accomplish
this. The trick is to limit the possible size of the breaker feeding the "2nd"
bus (the lower bus in this case). It's not rocket science.
>  
> I'd be happy to use and publicize a product that a mainstream manufacturer
came up with to deal with this. How about you?
>  
> $0.02001,
>  
> Solar Janitor
>  
> PS - Home rewiring for friends only. I love doing it, but I do it for love.
There ain't no amount of money that makes me want to do it just for money!
> From: re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] On Behalf Of Dana Brandt
> Sent: Thursday, October 28, 2010 5:19 PM
> To: RE-wrenches
> Subject: [RE-wrenches] backfeeding "six disconnect" panel
> 
> Hi everyone,
> 
> I'm working on two systems for homes that have the old style breaker panels
with no single main breaker. Instead, they have six breakers in the upper part
of the panel each labeled "main breaker," which satisfies the six disconnect
rule. The bus bar is split, with one of the six upper breakers (60A) feeding a
separate bus in the lower half of the panel. It appears that the upper bus is
rated for 200A, and the lower at 100A.  The sum of the main breakers does not
exceed the 200A rating of the upper bus. There are spare breaker slots on both
the top and bottom buses. How do I deal with 690.64 (B) (2) when there's no main
breaker? 
> 
> Thanks!
> 
> Dana
> 
> Dana Brandt
> Ecotech Energy Systems, LLC
> www.ecotechenergy.com
> dana@ecotechenergy.com
> 360.510.0433
>
--- end of quote ---

