[RE-wrenches] Line Side Feed In and Disconnects

Darryl Thayer daryl_solar at yahoo.com
Fri Mar 13 19:35:25 PDT 2009


The methods that I use on "Feed in Tariff" or REC When they are based on value of renewable energy generated, you come from the inverter to the utility (general purpose switch)Disco to the meter THEN to the main service panel end of bus breaker.  The energy generated from solar  is then read on the REC or Feed in Terrif meter, if the customer is not to recieve the reduction in bill, the tarrif meter is added to the stamdard utility meter, which has to be of the net meter type(reversible). 

If the main service is to small then first tap the feeds with double up lugs and connect ahead of the main breaker, in parallel, mount the Service rated disconnect to feed the solar inverter.  

Darryl 


--- On Fri, 3/13/09, Wayne Irwin <Wayne at PureEnergySolar.net> wrote:

> From: Wayne Irwin <Wayne at PureEnergySolar.net>
> Subject: Re: [RE-wrenches] Line Side Feed In and Disconnects
> To: "Wrenches" <re-wrenches at lists.re-wrenches.org>
> Date: Friday, March 13, 2009, 8:53 PM
> Yeah, Welcome to the World of the Feed In Tariff!
> 
> Oh Well! At least we have business.
> 
> Wayne Irwin, President
> 
> Pure Energy Solar International Inc. 
> 
> Lic # CVC56695 
> 
> Wayne at PureEnergySolar.net 
> 
> http://pureenergysolar.net 
> 
> 352 377-6527 Office
> 352 336-3299 Fax
> 352 316-1637 Cell
> 
> 
> 
> 
> From: sjohnson at lightwavesolarelectric.com
> To: re-wrenches at lists.re-wrenches.org
> Date: Fri, 13 Mar 2009 20:46:58 -0400
> Subject: Re: [RE-wrenches] Line Side Feed In and
> Disconnects
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Re: [RE-wrenches] Line Side Feed In and Disconnects
> 
> 
> 
> 
> 
> 
> 
> 
> Oh brother, that 230.72(A) is a nightmare.
> 
> TVA and their 160 distributors are in the process of going
> to a
> line side feed in tariff from a load side production
> credit.
> 
> Actually they plan on letting the distributor offer either
> or
> both options at their discretion.
> 
> I’m laying out  a job today with a standalone rack
> mounted 100 amp 3 phase 480 volt disconnect and feed thru
> meter out by the
> padmount transformer.
> 
> The existing service is 2500 amp and because the service
> was installed
> under the building slab (new building) there is no outdoor
> disconnect.
> 
> This means we would have to dig up a 2500 amp service and
> turn
> it up out by the padmount transformer. FORGET IT!  That’s
> a huge
> switch with 4 four inch conduits full of 400 MCM going in
> and going out of that
> switch. 
> 
>  
> 
> This is onerous.  Onerous I tell you! 
> 
> I would submit that the exception to 230.72 (A) for water
> pumps
> be amended to add clean renewable PV systems.
> 
> John Wiles are you out there?
> 
>  
> 
> 
> 
> Steve Johnson
> 
> LightWave Solar Electric
> 
> Nashville, TN
> 
> 
> 
>  
> 
> 
> 
> 
> 
> From:
> re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org]
> On Behalf Of David Brearley
> 
> Sent: Tuesday, March 10, 2009 12:28 PM
> 
> To: RE-wrenches
> 
> Subject: Re: [RE-wrenches] Line Side Feed In and
> Disconnects
> 
> 
> 
> 
> 
>  
> 
> Wayne,
> 
> 
> 
> As you suggested, because this is a new service, a PV
> service disconnect is
> required. The question of whether a second disconnect is
> required, a new
> disconnect for the main service, is a Code issue, as far as
> I can tell.
> It is also an interpretation, but I’ll get to that later.
> 
> 
> 
> It just so happens that the June/July issue of SolarPro
> magazine will
> have an extensive article on making PV interconnections.
> The authors are Ryan
> LeBlanc and Tarn Yates from SPG Solar. From their article,
> here are some Code
> articles that apply to selecting and locating a disconnect
> for a line side
> connection:
> 
> 
> 
> 230.66 – Disconnect shall be listed for use as service
> equipment.
> 
> 230.70(A)(1) – Disconnect shall be installed at a readily
> accessible
> location.
> 
> 230.72(A) – All service disconnects shall be grouped
> together.
> 
> 
> 
> The last article is no doubt the one that the AHJ is
> referencing in this case. 
> 
> 
> 
> The reason I feel that this extra expense and effort is an
> interpretation, as
> much as it is a Code issue, is that you could make a load
> side
> connection and still have the math work for the feed-in
> tariff program and for
> the revenue metering. 
> 
> 
> 
> How is that? 
> 
> 
> 
> Well, a meter on the inverter output circuits will read the
> total PV kWh for
> the feed-in tariff. A bi-directional meter for the revenue
> meter will read
> in-flow from the utility and out-flows to the utility. The
> difference between
> total PV kWh and the out-flow-kWh are the PV generated kWh
> that the customer
> used on site rather than export to the utility. Right?
> Whatever PV generated
> energy is not exported to the utility is used on site.
> 
> 
> 
> So for billing purposes the customer is charged as follows:
> 
> 
> 
> Total kWh for billing = In-flow kWh + (feed-in tariff kWh
> – out-flow kWh)
> 
> 
> 
> Theoretically, this can also be implemented affordably by
> the utility: move the
> exiting revenue meter to the PV system; add a $100
> bi-directional meter to the
> original meter can. Finished. 
> 
> 
> 
> Making a line-side connection is often difficult and
> expensive, especially when
> you now have to add a new service disconnect for the
> facility. At least in
> theory, it is also dangerous; the fault-currents there are
> higher. You have
> these implementation issues on the one hand. On the other
> hand you have a
> spreadsheet, or a one-time fix the the utility’s billing
> software. 
> 
> 
> 
> So I think the utility is making this more onerous than
> they need to.
> Especially for small generators, the cost of this service
> upgrade will kill the
> deal. The utility probably isn’t interested in this
> solution, but we can
> still dream of the perfect fix.
> 
> 
> 
> David Brearley, Technical Editor
> 
> SolarPro magazine 
> 
> NABCEP Certified PV Installer ™
> 
> david.brearley at solarprofessional.com
> 
> Direct: 541.261.6545
> 
> Fax:  541.512.0343
> 
> 
> 
> Visit our Web site at solarprofessional.com
> 
> 
> 
> On 3/9/09 5:25 PM, "Allan Sindelar"
> <allan at positiveenergysolar.com> wrote:
> 
> Wayne,
> 
> Use this as a tool:
> http://www.solarabcs.org/utilitydisconnect/
> 
> and this: http://www.nrel.gov/docs/fy08osti/42675.pdf
> 
> 
> 
>  
> 
> Allan Sindelar 
> 
> allan(at)positiveenergysolar.com
> <mailto:allan at positiveenergysolar.com>
>  
> 
> NABCEP Certified Solar PV Installer 
> 
> Positive
> Energy, Inc.
> 
> 
> 3201 Calle Marie 
> 
> Santa Fe NM 87507 
> 
> 505 424-1112 
> 
> www.positiveenergysolar.com 
> 
> 
> 
> Please consider the environment
> before printing this e-mail. 
> 
> 
> 
> -----Original
> Message-----
> 
> From:
> re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org]
> On Behalf Of Wayne Irwin
> 
> Sent: Monday, March 09, 2009 4:41 PM
> 
> To: re-wrenches at lists.re-wrenches.org
> 
> Subject: [RE-wrenches] Line Side Feed In and Disconnects
> 
> 
> 
> Hello
> Wrenches,
> 
> 
> 
> Here in Gainesville, Fla. we have recently adopted a Feed
> In Tariff. 
> 
> So, now we are supposed to directly feed the line side of
> the utility meter
> (essentially a new service). No big deal. 
> 
> As usual we use an AC disco between the inverter and the
> grid. However, the
> permit department is requiring that we install and
> additional disco between the
> existing service feed and the distribution panel to group
> all disco's in the
> same location. This especially adds an additional expense
> when dealing with 3
> phase systems as well as the raises the question, is this
> really the National
> Electrical Code or just an interpretation? Your thoughts?
> 
> 
> 
> Wayne Irwin, President
> 
> Pure Energy Solar International Inc. 
> 
> Lic # CVC56695 
> 
>  <mailto:PureEnergySolar at hotmail.com>
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Date:
> Mon, 9 Mar 2009 18:20:57 -0400
> 
> From: reellison at gmail.com
> 
> To: re-wrenches at lists.re-wrenches.org
> 
> Subject: Re: [RE-wrenches] Small Torque Wrench
> 
> 
> 
> I got mine from "the knife and tool store"
> http://myworld.ebay.com/don19470/
> on E bay. nice tool, adjustable 10 - 50 In Oz and he has
> others, just get the
> adapter that lets you use 1/4" drive bits and your
> good to go. It is a
> german tool and i use it on all breaker connections as well
> as others.
> 
>  
> 
> Later,
> 
> Bob
> 
> 
> 
> On Mon, Mar 9, 2009 at 12:10 PM, Peter Parrish
> <peter.parrish at calsolareng.com> wrote:
> 
> 
> 
>  
> 
> We have a great torque wrench for  snugging down module
> clamps,
> Sharp SRS bolts, etc. What do folks use to insure  that
> wire terminals are
> torqued to spec? We’re talking 1.1 to 3.3 N-m (10-30 
> in-lbs).
> I’m imagining something compact like an over-sized
> screwdriver.  
> 
>  
> 
> - Peter
> 
> 
> 
> Peter T. Parrish,  President
> 
> California Solar Engineering, Inc.
> 
> 820 Cynthia Ave., Los  Angeles, CA 90065
> 
> Ph 323-258-8883, Mobile 323-839-6108, Fax  323-258-8885
> 
> CA Lic. 854779, NABCEP Cert. 031806-26
> 
> peter.parrish at calsolareng.com  
> 
> 
> 
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