[RE-wrenches] SunnyIsland - was AC coupling and Outback inverters

Fri Oct 5 08:17:45 PDT 2012

We've had problems with the Outback auto transformer when used with Sunny Islands.  The internal resistance of the transformer bumped the voltage up too high on a couple of systems and we were getting over voltage errors in the inverter.  We switched to a larger transformer and that fixed the problem.

__________________________________________________________________________________________
Will White
Regional Field Operations Manager - New England

Real Goods Solar
64 Main St.
Montpelier, VT 05602
Tel: (802) 223-7804
Cell: (802) 234-3167
www.realgoodssolar.com

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of August Goers
Sent: Friday, October 05, 2012 11:14 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] SunnyIsland - was AC coupling and Outback inverters

I'm looking forward to checking out the SMA Smartformer. We're sending one of our guys to SMA training later this month to learn more about it is depth. Up to date, we used the Outback PSX-240 like the one found here to
120/240 step up:

http://www.altestore.com/store/Enclosures-Electrical-Safety/Miscellaneous-
Electrical-Parts/Transformers/Outback-PSX-240-Autotransformer-with-Fan/p40
89/

My experience with a handful of Sunny Island backup systems has been really good. The Sunny Island is a very solid piece of equipment and is easy to program if the plan is properly thought through and everything is wired properly.

Good luck with your project! -August

-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Dave Click
Sent: Friday, October 05, 2012 6:01 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] SunnyIsland - was AC coupling and Outback inverters

Check out the new SMA Smartformer, though I'm not sure whether it's actually shipping yet. I'm thinking about this for my house eventually (SB5000US).

http://www.sma-america.com/en_US/products/off-grid-and-back-up-solutions/s
martformer-for-sunny-island.html

Alternatively, the new SMA TL inverters (at least the 3, 4, and 5kW units according to the press release) have an "Emergency Power Supply"
function that can provide backup power (12A?) during the day when the grid is down. This may meet your customer's requirements. No batteries required, though since the TLs require ungrounded arrays, you may need to rewire the existing array to be compliant with 690.35 (PV Wire or raceway).

On 2012/10/5 8:41, Kirk Herander wrote:
> One Question: Output of the SunnyBoy is 240vac. So this is fed to the 
> critical load panel, of which the SunnyIsland 120 vac output is fed to.
> So we need a 120/240 step up transformer between the SunnyIsland and 
> the critical load panel to fully take advantage of the Sunnyboy array 
> for battery charging, correct?.
>
> Kirk Herander
>
> VT Solar, LLC
>
> dba Vermont Solar Engineering
>
> NABCEP^TM Certified installer Charter Member
>
> NYSERDA-eligible Installer
>
> VT RE Incentive Program Partner
>
> 802.863.1202
>
> *From:*re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of 
> *David Katz
> *Sent:* Friday, October 05, 2012 2:11 AM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] AC coupling and Outback inverters
>
> Hi Kirk,
>
> All of the Outback inverters will work AC coupled (GT and FX) as will 
> any bi-directional H-bridge type inverter.  I have used old Trace 
> SW's, SunnyIsland, Apollo TSW, Magnum AE and now I am using an Outback 
> Radian to do exactly what you are talking about.  I have 6 kW of grid 
> tie inverter and an additional 4kw of modules running through a 
> Xantrex 600 volt charge controller to the batteries that the Radian 
> runs on. It all works flawless as long as you have a provision for 
> protecting the batteries when the gid is down and the grid-tie PV 
> system is making more power than the loads are using.
>
> If the customer has SMA inverters, I would recommend using a 
> SunnyIsland because the battery control when the grid goes down is so
elegant.
> Everything else is a bit of a kludge.
>
> David Katz
>
> CTO & Founder
>
> AEE Solar Inc
>
> P: 707 825-1200
>
> F: 707 825-1202
>
> dkatz at aeesolar.com <mailto:dkatz at aeesolar.com>
>
> www.aeesolar.com <http://www.aeesolar.com>
>
> *From:*re-wrenches-bounces at lists.re-wrenches.org
> <mailto:re-wrenches-bounces at lists.re-wrenches.org>
> [mailto:re-wrenches-bounces at lists.re-wrenches.org]
> <mailto:[mailto:re-wrenches-bounces at lists.re-wrenches.org]> *On Behalf 
> Of *Kirk Herander
> *Sent:* Thursday, October 04, 2012 2:11 PM
> *To:* RE-wrenches
> *Subject:* [RE-wrenches] AC coupling and Outback inverters
>
> I have AC-coupled an Outback quad-stack with multiple SunnyBoy 6000US 
> inverters and it's been running fine for 4 years. I used the off-grid 
> version of Outbacks.
>
> Now I have an application where a customer wants to add battery backup 
> to an existing SunnyBoy 5000US system. And expand his array by a 
> couple KW. So I'm thinking of using a GT Outback w/ batteries to 
> handle the critical loads and feed the extra 2kw of PV (charging the 
> batteries through an MX60) to the grid. And I'd like to AC-couple the 
> SunnyBoy so the original 5 kw array can also charge the batteries, BUT 
> I remember, at least I think so, that the GT inverter cannot be 
> AC-coupled, only the off-grid version. Is this correct? Thanks.
>
> Kirk Herander
>
> VT Solar, LLC
>
> dba Vermont Solar Engineering
>
> NABCEP^TM Certified installer Charter Member
>
> NYSERDA-eligible Installer
>
> VT RE Incentive Program Partner
>
> 802.863.1202
>
>
>
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