Tesla replaced my MCI units because of poor production in the winter, but now it's much worse.

[Thomias]

@1SciChick,
Seems our systems are roughly the same age. Do you still have the original Delta Inverters? Or did they replace them with the Tesla Inverter?
I had no luck with support until I finally got through to the resolutions department. Even now it's dragging but they haven't completely brushed off my complaints.
Wish we didn't need the MCI units, but for safety reasons they need the system to be capable of discharging for first responders and service.
I'll keep you all posted on my progress and hope that it helps you and others with these issues.
My next appointment is Monday April 1, I believe they will just be taking photos of the roof/shading. However, it will likely be raining and therefor I do not expect anything will get accomplished.

 

[1SciChick]

@Thomias : We have the Tesla inverter, and one Powerwall were all installed by Tesla Energy. No replacement of the inverter as far as I know. The only part that has been replaced were the MCIs (first time all 3 were replaced, second time only one was replaced again) - still doesn't solve the problem. The technicians who came out to replace the MCIs said they are aware the MCIs are the cause of the production issues, but they haven't been able to find a long-term solution that can fix the problem for good and as you said, it is required by state code to have the MCIs. I also don't understand why this happened all of a sudden.

By any chance, when did your issue with solar production first occur? I think ours happened in June / July 2023 - right around the time when Tesla released the "Charge on Solar" update to the solar app. We also have Tesla EVs and that is the only thing that I could think of, that might be related to this sudden issue with the MCIs and solar production. I'm not an electrician or engineer, but It almost looks like the system has been throttled to not exceed a certain amount of electricity that can be produced.

 

[Vines]

@Thomias : We have the Tesla inverter, and one Powerwall were all installed by Tesla Energy. No replacement of the inverter as far as I know. The only part that has been replaced were the MCIs (first time all 3 were replaced, second time only one was replaced again) - still doesn't solve the problem. The technicians who came out to replace the MCIs said they are aware the MCIs are the cause of the production issues, but they haven't been able to find a long-term solution that can fix the problem for good and as you said, it is required by state code to have the MCIs. I also don't understand why this happened all of a sudden.

By any chance, when did your issue with solar production first occur? I think ours happened in June / July 2023 - right around the time when Tesla released the "Charge on Solar" update to the solar app. We also have Tesla EVs and that is the only thing that I could think of, that might be related to this sudden issue with the MCIs and solar production. I'm not an electrician or engineer, but It almost looks like the system has been throttled to not exceed a certain amount of electricity that can be produced.

If you have your plans can you attach them or take a picture of them? Interested to know the version of MCI.

 

[offandonagain]

If you have your plans can you attach them or take a picture of them? Interested to know the version of MCI.

I'll second that. When Tesla replaced my MCIs, they went from model MCI-1 to MCI2 (specs). They claimed MCI-2 is more reliable.

@1SciChick, I'm also surprised they only replaced 3 MCIs. There should be 1 MCI per 3 panels and based on your post (65 kwh/day in the summer months) your system sounds larger than 9 panels.

 

[Thomias]

Update - 2 Techs were out on Monday to assess the situation and take some photos.
Now I'm waiting to hear if back with any type of solution.

@Vines My design was posted earlier in the thread and that's all I have from Tesla. Nothing new in my portal either.
I have no information or documentation after my initial install. I do not know what the "bypass MCI" units were with the Delta in 2022, nor do I know what version the 2023 Tesla MCI units installed with the inverters.

@1SciChick My Tesla Inverters and MCI were installed that May/June of 2023 and were lower than previous 2 versions right away. Not sure if they were already updated or not since I was not given any additional info or specs. Difference with my system is that I had the Delta Inverters and MCIs first.

@offandonagain judging by the drawing I may have seen MCI-1 being installed but can't be certain. Maybe I can reach out and ask, or check if the Inverter APP can give me that info.

Thanks all, I will continue to update my progress.