[RE-wrenches] Sol-Ark 15K AC Output
Jason Szumlanski
jason at floridasolardesigngroup.com
Wed Mar 27 11:43:27 PDT 2024
They are certainly friendly, but I didn't get a straight and definitive answer
when I called about this. It should really be documented. There is no
documentation about how paralleled units share/balance inputs and pass current
through.
Regardless, I still think it is best practice to size the load conductors for
the sum of the full generator/grid input (on the grid input lugs) plus 62.5A, or
200A, whichever is less, even in a parallel system in case one unit ceases to
function or is removed for service.
Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956
Florida Certified Electrical Contractor EC13013208
On Wed, Mar 27, 2024 at 8:03 AM Michael Morningstar via RE-wrenches
<re-wrenches at lists.re-wrenches.org> wrote:
> Sol-Ark's applications engineers are your friends : )
>
> On Wed, Mar 27, 2024 at 3:13 AM Jason Szumlanski via RE-wrenches
> <re-wrenches at lists.re-wrenches.org [re-wrenches at lists.re-wrenches.org]> wrote:
>
> > William,
> >
> >
> > Thanks for the information on grid peak shaving. That is what I thought
> > could be done. The description is a misnomer of sorts (like a lot of things
> > in Sol-Ark lingo). It's a bit hard to follow and not nearly well
> > enough documented, particularly with respect to parallel systems.
> >
> >
> > I follow what you are saying about using the 80A input breakers. The problem
> > I have is that you must set the generator kW to 36,000 in the master
> > inverter, not 9,000W in each inverter. The concept of "underrating" the
> > input breakers theorizes that each inverter will share the generator
> > pass-through equally. I do not know that to be the case. And what happens if
> > the three slave inverters have a fault or are turned off? That would allow
> > the single master to pass through the full generator supply. Obviously this
> > trips the 80A input breaker and protects the conductors, but I feel that is
> > a design deficiency when a single inverter is fully capable of passing
> > through all 150A.
> >
> >
> > On top of that, I don't think the 80A output breakers are sufficient because
> > each inverter can peak shave 50A with inverter power from the batteries. Add
> > that to the theorized balanced 37.5A "grid" input, and you are at 87.5A of
> > possible throughput.
> >
> >
> > But assuming the 80A input/output concept works, other than a panelboard
> > with bolt on breakers, what low-cost load center allows you to fasten four
> > 80A backfed breakers? If this is available, I could use a recommendation.
> > The load centers I am familiar with only have provisions for one fastened
> > backfed breaker.
> >
> >
> > With respect to the bypass, I would usually use a DPDT switch to accomplish
> > this, Even for 400A bypasses, there seems to be a relatively cost effective
> > option in the Ronk 7416 (which to date I have not used). I get the concept
> > for smaller (<=100A) generators that you could use a generator interlock on
> > an off-the-shelf load center. But they typically only allow a single backfed
> > 2-pole breaker, whereas something like a Square D QO panel with a backfed
> > 150A breaker requires 4 spaces and is incompatible with the interlock
> > device.
> >
> >
> > Always, this is a great discussion and specific recommended equipment is
> > appreciated.
> >
> > Jason Szumlanski
> > Principal Solar Designer | Florida Solar Design Group
> > NABCEP Certified Solar Professional (PVIP)
> > Florida State Certified Solar Contractor CVC56956
> > Florida Certified Electrical Contractor EC13013208
> >
> >
> > On Wed, Mar 27, 2024 at 12:33 AM William Miller <william at millersolar.com
> > [william at millersolar.com]> wrote:
> >
> >
> > > Jason:
> > >
> > >
> > >
> > > Sol-Arc does provide generator support. They call it “grid peak load
> > > shaving” and it is described on page 22 of the manual. Below is an
> > > excerpt.
> > >
> > >
> > >
> > > [data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7]
> > >
> > >
> > >
> > > For those that may not be familiar with the concept of generator support,
> > > here is how I describe it: The inverter(s) are programmed for the
> > > generator capacity. If the generator is powering loads and the demand
> > > exceeds that programmed generator capacity, the inverter can start
> > > inverting and synchronize output to the generator to add power. This is
> > > only possible if battery charge levels are adequate. In the Sol-Arc this
> > > function can be adjusted or turned off.
> > >
> > >
> > >
> > > Regarding my recommendations on wire sizing: I may have done a poor job
> > > describing how I see your project best approached. Below is a diagram
> > > that may do a better job. Power flow is from left to right:
> > >
> > >
> > >
> > > [data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7]
> > >
> > >
> > >
> > > If you follow what I am laying down, you can see there is no single
> > > inverter or inverter wire that can pass or create more than 80 amps. Ergo
> > > #4 copper. The money and time you save can easily purchase 8 80 amp
> > > breakers. If you look at Diagram 10 in the April 5, 2022 Sol-Arc manual
> > > you will see this concept shown, albeit without bypass capabilities and
> > > with a separate “LOAD AC Combiner panel.” The separate panel is
> > > redundant,-- all of the breakers in the AC combiner panel could be located
> > > in the “Main Breaker Panel.”
> > >
> > >
> > >
> > > Contemplate this: Just because an inverter can pass-through 200 amps,
> > > does not mean it can pass through amps above what the input breaker
> > > provides.
> > >
> > >
> > >
> > > I hope I have been more clear. I also hope you don’t spend a lot of money
> > > on and wrassle wire larger than is needed.
> > >
> > >
> > >
> > > Call me if I can help in any way.
> > >
> > >
> > >
> > > William
> > >
> > >
> > >
> > > PS: Below is a diagram on how to provide bypass. I tried to depict the
> > > bypass interlock graphically. The point is you cannot turn on the bypass
> > > breaker without turning off the inverter output breakers. See photos of
> > > the actual hardware on the web page linked below. I find bypass very
> > > handy because if there is an inverter or battery failure the client can
> > > restore power immediately and I can respond at a more convenient time.
> > >
> > >
> > >
> > >
> > >
> > > [data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7]
> > >
> > >
> > >
> > >
> > >
> > > Wm
> > >
> > >
> > >
> > > Miller Solar
> > >
> > > 17395 Oak Road, Atascadero, CA 93422
> > >
> > > 805-438-5600
> > >
> > > www.millersolar.com
> > > [https://mailtrack.io/l/3deb3f7f51095bae3cfd8b42df221b4dca044e0a?url=http%3A%2F%2Fwww.millersolar.com%2F&u=1613865&signature=79e9e2e0e8d662d0]
> > >
> > > CA Lic. 773985
> > >
> > >
> > >
> > >
> > >
> > > From: Jason Szumlanski [mailto:jason at floridasolardesigngroup.com
> > > [jason at floridasolardesigngroup.com]]
> > > Sent: Tuesday, March 26, 2024 6:41 PM
> > > To: William Miller; RE-wrenches
> > > Subject: Re: [RE-wrenches] Sol-Ark 15K AC Output
> > >
> > >
> > >
> > > #4 wire as the output of each inverter is definitely not adequate, as each
> > > inverter can pass through 150A of generator power. In theory it would be
> > > spit across all four, but that doesn't matter. It's an open spigot, so at
> > > a minimum the output conductors would need to be 150A rated in my opinion.
> > > The complication arises when you don't know whether the inverter can
> > > supplement this AC output all the way to the 200A load OCPD integral to
> > > the inverter. For that reason, I believe you need to size the output
> > > conductors to 200A, not 150A in this case. I am trying to find out
> > > definitively if generator support mode is supplied by Sol-Ark s.
> > >
> > >
> > >
> > > As for paralleling the outputs, landing the outputs on breakers becomes
> > > problematic and very expensive. Since the outputs need to be 150A minimum
> > > or 200A maximum (as discussed previously), how would you do a 400A
> > > panelboard with four of these large breakers in it, keeping in mind that
> > > all four need to be fastened as backfed main breakers? I don't see a
> > > practical way to make that happen.
> > >
> > >
> > >
> > > The same thing applies to combining the generator inputs. You would need 4
> > > x 150A backfed breakers, all fastened to the bus. Is there a cost
> > > effective way to accomplish this?
> > >
> > >
> > >
> > > Serviceability and bypass are obvious desires, but at what cost? If an
> > > inverter needs to be taken out of service, it's fairly easy to remove the
> > > supply and load conductors. And this highlights my issue... What if three
> > > of four inverters need to be removed from service? Then absolute 150A
> > > generator power can flow through the remaining single inverter, meaning
> > > the output conductors need to be sized accordingly.
> > >
> > >
> > >
> > > Jason
> > >
> > >
> > >
> > >
> > >
> > > On Tue, Mar 26, 2024, 9:15 PM William Miller via RE-wrenches
> > > <re-wrenches at lists.re-wrenches.org [re-wrenches at lists.re-wrenches.org]>
> > > wrote:
> > >
> > > > Jason:
> > > >
> > > >
> > > >
> > > > I am wondering on the advisability of hardwiring the outputs of all four
> > > > inverters together. If one inverter fails the other three can backfeed
> > > > into it without any means to disconnect the failed inverter and without
> > > > over-current protection. Have you considered landing the output of each
> > > > inverter on a separate, appropriately sized 2 pole breaker in the output
> > > > load-center?
> > > >
> > > >
> > > >
> > > > In the same vein, how are you feeding generator input into the
> > > > inverters? Are these hard-wired paralleled as well? You might consider
> > > > having the generator feed a dedicated load-center with an appropriately
> > > > sized breaker to feed each inverter. You protect the conductors as
> > > > required and you can isolate any inverter for service
> > > >
> > > >
> > > >
> > > > What size should these breaker be? If your inverter can supply 62.5
> > > > AAC, upsizing for continuous duty and to the next higher standard
> > > > breaker size you get 80 amps. If you use 80 amp breakers into and out
> > > > of each Sol-Arc you require #4 copper at 75°C. Each inverter and all of
> > > > the conductors are protected for the max current they will see and you
> > > > get the combined amperage at your output. There should be no need to
> > > > run 400 amp wire.
> > > >
> > > >
> > > >
> > > > BTW, you can easily contrive a bypass system by creating a sliding
> > > > mechanical interlock. You run an appropriately sized feeder between the
> > > > generator fed and inverter fed panels. The bypass breaker in the
> > > > inverter-fed panels is interlocked with the inverter output breakers.
> > > > The installation might look like this
> > > > [https://mailtrack.io/l/e90ccdb6d87171ee02747bc52f4aa4c7f57064ca?url=https%3A%2F%2Fmillersolar.com%2FMillerSolar%2FPortfolio%2FInverters%2Fbattery_iinverters%2FChimney_Rock%2FChimney_rock.html&u=1613865&signature=38c4488f52bdc385].
> > > > This is way cheaper and easier than installing an additional 200A,
> > > > double-throw safety switch. (A home-made interlock may not be listed
> > > > but what is the worse that will happen if all breakers are on? The
> > > > inverters will detect backfeed and shut down. No harm will come of it.)
> > > >
> > > >
> > > >
> > > > Hope this helps.
> > > >
> > > >
> > > >
> > > > William
> > > >
> > > >
> > > >
> > > > Miller Solar
> > > >
> > > > 17395 Oak Road, Atascadero, CA 93422
> > > >
> > > > 805-438-5600
> > > >
> > > > www.millersolar.com
> > > > [https://mailtrack.io/l/7e13e4b3b56e5496552a9f21904f404635490f63?url=http%3A%2F%2Fwww.millersolar.com%2F&u=1613865&signature=6c634bcc39faeca3]
> > > >
> > > > CA Lic. 773985
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > From: RE-wrenches [mailto:re-wrenches-bounces at lists.re-wrenches.org
> > > > [re-wrenches-bounces at lists.re-wrenches.org]] On Behalf Of Jason
> > > > Szumlanski via RE-wrenches
> > > > Sent: Tuesday, March 26, 2024 2:26 PM
> > > > To: RE-wrenches
> > > > Cc: Jason Szumlanski
> > > > Subject: [RE-wrenches] Sol-Ark 15K AC Output
> > > >
> > > >
> > > >
> > > > I am going to have a quad-stack of Sol-Ark 15K for an off-grid 120/240V
> > > > system with a 150A generator. I know the max real power is 62.5A each
> > > > inverter including battery and PV. That would be 62.5A x 4 = 250A total.
> > > > I intend to connect the output of the 4 inverters together with a 5-port
> > > > Polaris tap, with the output of the Polaris Tap going to a 400A main lug
> > > > only panelboard.
> > > >
> > > >
> > > >
> > > > My question revolves around the 200A passthrough capability for the
> > > > generator, which is 150A max output and would be connected to the Grid
> > > > input on each inverter. Since each inverter would need to handle the
> > > > full pass-through current, that would require minimum 150A conductors on
> > > > the input side of each inverter. I am under the impression that the
> > > > inverters can supplement the "grid" or generator in this case if the
> > > > current exceeds the available input. That means the inverter would have
> > > > 150A of input plus 62.5A of inverter power for a total of 212.5A. But
> > > > there is a 200A load OCPD, so I could size the load conductors from each
> > > > inverter for 200A.
> > > >
> > > >
> > > >
> > > > Obviously the 4 inverters can only pass through 150A from the generator
> > > > in total, which would probably be split among them, but could go through
> > > > a single unit if the rest fail.
> > > >
> > > >
> > > >
> > > > Now, is it possible for each inverter to output 62.5A each PLUS 150A of
> > > > generator power spread across them for a total of 400A? That is
> > > > important because I would need to size the combined output conductors
> > > > for 400A if that is the case.
> > > >
> > > >
> > > >
> > > > I guess I'm not clear on how Sol-Ark 15K handles grid/generator
> > > > assist/supplement. It does not seem to be documented clearly.
> > > >
> > > >
> > > >
> > > > Jason Szumlanski
> > > >
> > > > Florida Solar Design Group
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > List sponsored by Redwood Alliance
> > > >
> > > > Pay optional member dues here: http://re-wrenches.org
> > > > [https://mailtrack.io/l/5f5ecb45fa0ccb0d11cccafb2c0f97618fa79e70?url=http%3A%2F%2Fre-wrenches.org&u=1613865&signature=fdeabe6cf92ab25a]
> > > >
> > > > List Address: RE-wrenches at lists.re-wrenches.org
> > > > [RE-wrenches at lists.re-wrenches.org]
> > > >
> > > > Change listserver email address & settings:
> > > > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
> > > > [https://mailtrack.io/l/020c93287659704ad1c52093f304e341f5d0498c?url=http%3A%2F%2Flists.re-wrenches.org%2Foptions.cgi%2Fre-wrenches-re-wrenches.org&u=1613865&signature=3efe2a50c80c33a7]
> > > >
> > > > There are two list archives for searching. When one doesn't work, try
> > > > the other:
> > > > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> > > > [https://mailtrack.io/l/52cc42ac082af0eeca614dbe4c0d638d5d336ad1?url=https%3A%2F%2Fwww.mail-archive.com%2Fre-wrenches%40lists.re-wrenches.org%2F&u=1613865&signature=209030a25db2ff5a]
> > > > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
> > > > [https://mailtrack.io/l/f48fe27d75d453c7157b484946d36bcdf4698ad0?url=http%3A%2F%2Flists.re-wrenches.org%2Fpipermail%2Fre-wrenches-re-wrenches.org&u=1613865&signature=42f5213a717423ce]
> > > >
> > > > List rules & etiquette:
> > > > http://www.re-wrenches.org/etiquette.htm
> > > > [https://mailtrack.io/l/076ca2ee1c125ea468d20fa3e4c460f58b568b0d?url=http%3A%2F%2Fwww.re-wrenches.org%2Fetiquette.htm&u=1613865&signature=96238382e5fb3b50]
> > > >
> > > > Check out or update participant bios:
> > > > http://www.members.re-wrenches.org
> > > > [https://mailtrack.io/l/d6a9b62f894eaeef0e7d7d91724b427d785ae85e?url=http%3A%2F%2Fwww.members.re-wrenches.org&u=1613865&signature=e4238f11cf07c6fa]
> >
> > _______________________________________________
> > List sponsored by Redwood Alliance
> >
> > Pay optional member dues here: http://re-wrenches.org
> > [http://re-wrenches.org]
> >
> > List Address: RE-wrenches at lists.re-wrenches.org
> > [RE-wrenches at lists.re-wrenches.org]
> >
> > Change listserver email address & settings:
> > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
> > [http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org]
> >
> > There are two list archives for searching. When one doesn't work, try the
> > other:
> > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> > [https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/]
> > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
> > [http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org]
> >
> > List rules & etiquette:
> > http://www.re-wrenches.org/etiquette.htm
> > [http://www.re-wrenches.org/etiquette.htm]
> >
> > Check out or update participant bios:
> > http://www.members.re-wrenches.org [http://www.members.re-wrenches.org]
>
>
>
>
> --
>
>
> Michael Morningstar
>
>
>
>
> Morningstar Electric Inc
>
> PO Box 1494
>
> Mount Shasta, CA 96067
>
> 530-921-0560
>
> CSLB 1116835
>
> mjmorningstar at gmail.com [mjmorningstar at gmail.com]
>
>
>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org [http://re-wrenches.org]
>
> List Address: RE-wrenches at lists.re-wrenches.org
> [RE-wrenches at lists.re-wrenches.org]
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
> [http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org]
>
> There are two list archives for searching. When one doesn't work, try the
> other:
> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> [https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/]
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
> [http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org]
>
> List rules & etiquette:
> http://www.re-wrenches.org/etiquette.htm
> [http://www.re-wrenches.org/etiquette.htm]
>
> Check out or update participant bios:
> http://www.members.re-wrenches.org [http://www.members.re-wrenches.org]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20240327/c4744fca/attachment.htm>
More information about the RE-wrenches
mailing list