[RE-wrenches] Electrical manufacturers ready for PV?

[William Miller]

Friends:

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.

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.

My research did turn up some interesting information:

1. Square D offers a "PV Ready" MMC.  The data sheet for it can be found on 
our resources page:  http://millersolar.com/resources/resources.html  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.

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.

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.

Sincerely,

William Miller.


Please note new e-mail address and domain:

William Miller
Miller Solar
Voice :805-438-5600     Fax: 805-438-4607
email: william at millersolar.com
http://millersolar.com
License No. C-10-773985
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