3 250 classic w/SMA communication resting

[Whulljr]

Hello,
This is a new setup.  I have 3 250 classics setup with two sunny island and an SMA communication adapter.  All units are setup with SMA under misc.  When you power on the PV system they will say SMA bulk and export as required.  Then one or two of the classics will just go to resting after a few hours.   The voltage is over 170vdc and it's sunny out..  I understand if this was an off-grid system and you don't want to overcharge the battery bank but this is grid tied and I would like to export or feed the electrical load.  What seems to be the issue.  Thanks for the assistance!
Wes

[ClassicCrazy]

 I don't know a thing about your inverter.
It almost sounds to me like the Classics filled up the batteries and then they aren't going to put in any more power than to keep it in Float for the day.
It must be some settings with your inverter. I doubt the Classics get any charging instructions from the SMA system and are independently doing their charging on how they are programmed.
So if the battery isn't low , they won't charge.
You probably need to figure out your SMA settings.
That is my guess.
There is someone who had a long post in the forums here in the past year about maybe the same type setup . You might want to search the forums and read his posts and contact him for advice.
When you search go to the first main forum page or it won't work.

Larry

[boB]

Sounds like the batteries, being told by the SMA Sunny Island inverter, were charged by the three (3) Classic 250s and then, not needing all 3 Classics, are being held up by a single Classic.  Most likely in a constant voltage charge state like Absorb or Float.

Usually, when multiple Classics are used, after high power is not needed anymore, only one or two of the Classics will be needed because the batteries just don't need that much power or current anymore.

What is your battery voltage at this time and what does the status of the one Classic that is still running say ?

SMA Absorb ?  SMA Float ?   SMA  MPPT/BULK  (I forgot which one it would say)  or are all 3 batteries Resting ?

I am guessing at the moment that the situation is like I described above but let us know the status of the one Classic that is still running

[FNG]

Hello,
This is a new setup.  I have 3 250 classics setup with two sunny island and an SMA communication adapter.  All units are setup with SMA under misc.  When you power on the PV system they will say SMA bulk and export as required.  Then one or two of the classics will just go to resting after a few hours.   The voltage is over 170vdc and it's sunny out..  I understand if this was an off-grid system and you don't want to overcharge the battery bank but this is grid tied and I would like to export or feed the electrical load.  What seems to be the issue.  Thanks for the assistance!
Wes

If you are using this as a grid tie you need to remove the SMA Comm adapter, The issues:

1- SMA Sunny Islands only sell to the grid when something pushes the battery voltage above the setpoint they are targeting
2- The SMA comm adapter allows the Sunny Island to control the classics and throttle them down to maintain the target the Sunny Island wants

What you want to do is remove the SMA comm adapter, Reprogram the classics to be say 1v above the sunny islands set points. I recommend setting the Classic to what the battery manufacturer recommends and set the Sunny Island about 1v lower. Now the classics can push the battery voltage above the sunny islands and they will sell to the grid

[Olibri]

I have a similar configuration with a Classic 200 and an SMA 6048-US using the communications adapter.  I won't claim to be an expert, but the SI may throttle the Classic, meaning that when the batteries are full, the SI will stop requesting power or at least reduce the power requested to the power load.  You can confirm that this is what is happening to you by forcing the grid to be enabled (assuming that you are in GridFeed mode) by setting GdManStr (560.01) to Start.

WRT the prior post wrt raising the voltage, I have not tried this but the description is how this is supposed to work (per the manual).  However, depending on your use case (such as selling to the grid and only using the SI has backup), you can just leave GdManStr as Start and you will just always be connected to the grid.