Poor Grid Setpoint Tracking Multiplus IIs in Parallel

I upgraded my single 5kVA multiplus II to two of them in parallel.

Since the upgrade the grid setpoint tracking is A LOT worse than it was before.

With the one multi it was tracked very well. Now with the second one, there is a lot of feed in back in the grid and as the load increase, the feed back gets more. For example with a load of about 5kw there is a constant feed in back to the grid of 300W. With about 2.5kw there is a constant feed back to the grid of about 200W. And with low loads there is a constant feedback of about 50-100W. This isnt spikes when the load changes, but a constant feedback.

Luckily my prepaid meter doesnt trip - but it is charging me for the feed back into the grid…

Does anybody know how to improve the grid setpoint tracking when you use multis in parallel? Does it help to use an external energy sensor?


How old is the first Multi? If older than 18 months, its not compatible with the newer hardware models.

If they are the same hardware version, you have higher impedance on the input of one inverter and that causes the same symptoms.

Please ensure you input and output wires are exactly the same length and no loose connections. Also try making the new one the master, it might help.


You can phone me on 0713413280, and I can quickly explain what I am trying to say above.


Thanks Jaco for all the help!