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Friends:<br><br>
It is my opinion that electrical manufacturers have consistently lagged
behind the PV industry in providing specific specific hardware to meet
690 requirements. For example, we have an installation in progress
with 3 XW6048 inverters. We need this many inverters for battery
back up of essential equipment in an agricultural business. The
three inverters have a capability of feeding 75 amps back into the grid,
even though the PV size is modest. There is in place a 100 amp
service. I need to upgrade the bus bars to meet 690.64(B). I
had hoped to install a 200A Meter/Main/Combo and downgrade the main to
100 amps. My wholesaler contacted GE and was assured that a 200 MMC
was field retro-fittable for a 100 A main breaker. Alas, after
biding the job, purchasing the equipment and scheduling an inspection and
utility disconnect/reconnect, we discover that the MMC is not
retro-fittable.<br><br>
Frantic calls resulted in discovering that none of the manufacturers
allow downgrading a factory installed main breaker. The common
response is, "Why would you want a smaller main breaker?"
It is disappointing that 9 years after net metering became a reality,
manufacturer's still don't understand the particular needs of the solar
industry.<br><br>
My research did turn up some interesting information:<br><br>
1. Square D offers a "PV Ready" MMC. The data sheet for
it can be found on our resources page:
<a href="http://millersolar.com/resources/resources.html" eudora="autourl">http://millersolar.com/resources/resources.html</a>
Look under Square D. The PV ready part of this service gear
consists of a hold-down for a line side feed in breaker and places to put
CTs. I have never needed the CTs, and the hold-down is no longer
required in any jurisdiction I am aware of. What is conspicuously
lacking is a place for a 690.64(A) point of connection. Also
lacking is a surface mount version. I don't see that this device is
PV ready at all.<br><br>
2. Also available is a MMC known informally as a "Ranch
Panel." The Spec.drawing is also available on our web site at
the address above. Interestingly, this panel does have a
supply side POC, but after reading the fine print, the breaker for that
POC is limited to 50 amps. My arithmetic says a 200A residential
panel can accept 40A of PV. With this Ranch panel, I can gain a
whopping 10A of PV back feed. This is anti-climatic as I was hoping
for a true supply side tap.<br><br>
I am hoping that manufacturers begin to provide down-gradable main
breakers and readily accessible supply side POCs. Schneider
purchased Xantrex, maybe a Xantrex engineer (Mark?) can place a
request with Square D. If anyone on this list has connections in
the industry, please pass on this request.<br><br>
Sincerely,<br><br>
William Miller.<br><br>
<x-sigsep><p></x-sigsep>
<font size=3><u>Please note new e-mail address and domain:<br><br>
</u>William Miller <br>
Miller Solar<br>
Voice :805-438-5600 Fax:
805-438-4607<x-tab> </x-tab><br>
email: william@millersolar.com<br>
<a href="http://millersolar.com/" eudora="autourl">http://millersolar.com<br>
</a>License No. C-10-773985<br>
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