Using CTs to backed main panel have unwanted grid feed

[ricardocello]

Yes the ESS setpoint is the minimum draw from the grid.
It tries to keep grid consumption there, but can’t always react fast enough.

If you set the grid setpoint to zero, it tries to zero out the power from the grid.
Which sounds great in practice, but you will certainly push back power to the grid occasionally.
So the general recommendation is to keep it at 50 or 100W as a buffer.

If you set it to 1000W, then if a 1000W load switches off, for about a second the grid draw will drop to 0W, but it won’t go negative.
Going negative means the PoCo can detect it.

If the CTs and power meter and control loop were faster, there would be less time in the grid feedback.
The EM530 is the best you can do right now.

 

[ricardocello]

@jwy224
Watch this thread for a good conversation about this topic in general.
Thread 'Question About Preventing Grid Backfeed'
https://diysolarforum.com/threads/question-about-preventing-grid-backfeed.85969/

 

[jwy224]

@jwy224
Watch this thread for a good conversation about this topic in general.
Thread 'Question About Preventing Grid Backfeed'
https://diysolarforum.com/threads/question-about-preventing-grid-backfeed.85969/

Thanks for all you input and advice. I have read that thread as well as a lot of others. I do mess around with the grid setpoint but it does not seem to work as others have described. I think this weekend I will do a settings backup, and factory reset my cerbo and quattro's and see if maybe that changes the way my grid setpoint behaves. Thanks again.

 

[jwy224]

The way the grid set point seams to be working for me is if I set it to say 250w to will only allow 250w into my inverter and the rest is powered by my batteries for the critical loads. This does not apply to the grid coming into my house. Is this normal behavior?

 

[ricardocello]

The way the grid set point seams to be working for me is if I set it to say 250w to will only allow 250w into my inverter and the rest is powered by my batteries for the critical loads. This does not apply to the grid coming into my house. Is this normal behavior?

With ESS, the power will come from your solar or your batteries (in that order) to power the loads, and use no nore than 250w of grid,
as long as the battery SoC is above the Minimim SoC. When the battery is depeted to that level, then the ESS draws as much as it needs from the grid. There is no harm in having a really high minmum SoC like this:





There are also ways to schedule when this happens with Scheduled charge levels, which I use extensively.

 

[jwy224]

With ESS, the power will come from your solar or your batteries (in that order) to power the loads, and use no nore than 250w of grid,
as long as the battery SoC is above the Minimim SoC. When the battery is depeted to that level, then the ESS draws as much as it needs from the grid. There is no harm in having a really high minmum SoC like this:

View attachment 223735

View attachment 223736

There are also ways to schedule when this happens with Scheduled charge levels, which I use extensively.

Got it, thanks.
I did just hook up my critical loads panel so that will help I think.