[RE-wrenches] Charge Control in AC coupled system

[Drake]

Greetings Wrenches,

I want to AC couple 8 Enphase M190s to a pair of Outback inverters, 
stacked in split phase.  The use of micro inverters could allow for 
great method of controlling charge to the batteries.  A morning Star 
Relay Driver could be employed to disconnect one or more inverters at 
a time, to taper charge.

Have any Wrenches AC coupled this many Enphase micro inverters to 
Outbacks?   Have you had any problems?

Thank you,

Drake



At 05:07 PM 10/28/2010, you wrote:
>We have done several of these systems with various inverter 
>combinations. We used a voltage activated relay in the stone age to 
>switch inverters between battery banks and the grid before the Trace 
>SW came on scene. This little switch opens and closes a relay based 
>on user adjustable set points. Just put a current carrying relay 
>between the two inverters and use this unit to open and close it at 
>your battery set points. You are simulating a power failure to the 
>sell back inverter when the relay opens.
>Contact me off list if you need one. I have cases of them, new and 
>in the box. Still love the old SW's, even if they did cost me a fortune.
>Nathan Jones
>Power Source Solar
>Springfield, MO
>417-827-0738
>
>On Thu Oct 28th, 2010 3:32 PM CDT Mark Dickson wrote:
>
> >We have done one this way and came up with a good solution that has been
> >working great for two years now.  However, this is proprietary information,
> >so tough . . .!
> >Just kidding. . .
> >We used a Morningstar Relay driver to control 3 different "dump loads" that
> >turn on at consecutively increasing battery voltages.  The fourth relay that
> >kicks on is one that cuts the Outback's AC power to the Sunnyboys and shuts
> >the solar down just in case the dump loads fail or if they are getting way
> >more solar than they can utilize.  The dump loads that come on prior to this
> >are various heaters and ice melt systems.  These dump loads work out great
> >since the customers are only there in the summer and they rely on these
> >heaters to keep their fancy home from freezing in the winter.
> >
> >Best regards,
> >
> >Mark Dickson,
> >NABCEP Certified Solar PV Installer T
> >Oasis Montana Inc.
> >
> >
> >-----Original Message-----
> >From: re-wrenches-bounces at lists.re-wrenches.org
> >[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Howie
> >Michaelson
> >Sent: Thursday, October 28, 2010 2:00 PM
> >To: RE-wrenches
> >Subject: [RE-wrenches] Charge Control in AC coupled system
> >
> >Hi All,
> >
> >I have done several AC coupled off-grid systems using Sunny Islands and
> >Sunny Boys, but I am now doing one with a dual stacked OB VFX3648 (with a
> >PSX240 on the Inverter out for load balancing) and a SB3000.  There is
> >also an existing array that is running through an MX60.  What I am
> >wondering about is how folks have set up AC coupled string inverters to
> >best utilize the solar gain while not toasting the batteries.  I'm a big
> >fan of the tapering control offered by SMA through the frequency shift of
> >the SI's, but that's not available here.  What relay/contactor setup have
> >folks found most efficient and safe?  Thanks in advance,
> >
> >Howie
> >--
> >Howie Michaelson
> >NABCEP Certified Solar PV InstallerT
> >
> >Sun Catcher, LLC
> >Renewable Energy Systems Sales and Service
> >VT Solar & Wind Incentive Program Partner
> >http://www.SunCatcherVT.com
> >(cell) 802-272-0004
> >(home) 802-439-6096
> >