My Sunsynk Inverter has been intermittently sending excess electricity back to the grid. It occurred today at 9:30 AM, with a power output of 126 watts, and yesterday at 10:05 AM, with a power output of 86 watts. Why is that happening?

 

The system 2 settings; Zero Export - Checked 

 

 

Edited June 2, 20233 yr by Johan2

25 minutes ago, Johan2 said:

My Sunsynk Inverter has been intermittently sending excess electricity back to the grid. It occurred today at 9:30 AM, with a power output of 126 watts, and yesterday at 10:05 AM, with a power output of 86 watts. Why is that happening?
The system 2 settings; Zero Export - Checked

íf this happens intermittently and for short periods then its not an issue - that normally causes this is that a high power device switches off - the inverter would have been powering this device and then has nowhere to dump that energy so it pushes it back to the grid momentarily 

It depends on your settings. Please share your Work Mode settings, to see if you have selling or export activated, or if you are limiting solar production to your household loads.

Short blips are usually not an issue as long as your meter is not tripping, but you probably don't want to be exporting power into the grid without approval or without a suitable bi-directional meter installed. 

Its just a 5 minute "blib" I only noticed yesterday and today. My meter does not trip.

Your chart is from SunSynk / SolarMan App - they only update every few minutes.

I suspect the graph is just an instantaneous sample of -126W grid and not the average.
On SolarAssistant which is much more real-time you can see these grid feeds for a second before the inverter reverts to a 20W draw.

 

Edited June 2, 20233 yr by system32

On 2023/06/02 at 10:26 AM, Johan2 said:

My Sunsynk Inverter has been intermittently sending excess electricity back to the grid. It occurred today at 9:30 AM, with a power output of 126 watts, and yesterday at 10:05 AM, with a power output of 86 watts. Why is that happening?

 

The system 2 settings; Zero Export - Checked 

 

 

Nothing abnormal here, the method used by the inveter to measure the load requirement of items on the non essential circuit is not always 100% accurate and can often not react fast enough to varying loads.

This can result in the inverter sending to much power to the non essential circuit which shows up as feedback into the grid (if the power is not used by your non essential items that is the only place it can go). It can also have the opposite impact where small amounts of grid is used to supplement the shortfall supplied by the inverter.

Edited June 9, 20233 yr by I84RiS