Poor solar production has my cheap junk finally come to bite me?

[ThaiTaffy]

So even with easily accessible graphs and figures it's almost taken me a week to notice but my production has tanked.

My vmp is at or below rated vmp nowhere near voc so I'm unsure if it's the panels or the inverter. I have a load greater than production so its not normal clipping I had a quick glance over connections and they visually seem fine but it's too hot to stay on the roof for longer than 2 minutes currently, I'll do a better check tonight and disconnect things and go over everything.
The reduction in power seems to be stable which confuses me somewhat any of you smart folks might be able to shed any light on what might be happening?

The inverter is a Powmr POW-HVM2H-12V-N
Panels are Nakita 380w mono
currently outputting 2 amp in good sun nowhere near the 12.5amp Imp

Here's a graph showing the production drop:


As I said I'll do some further testing and inspection when it cools down, any suggestions other than the obvious to check?
Resistance through the DC breakers/DC SPD, check resistance through the PV cables, check connections, I've ordered some decent mc4 connections but they're unlikely to be here atleast for a few more days.

 

[profesor79]

That looks scary...
It can be one panel that is giving your trouble - will you have ability to have mc4-mc4 lead to skip one panel and see the results?
How many panels do you have? - as your MPPT charger starts at 120V Voc, then at 380W 4 panels in my opinion shall be a minimum in a string.

I had similar issues with my easun charger that I am investigating, but it restarts the produced power after it is disconnected from PV and battery for a 5 minutes.

btw were the days from 27th to 30th cloudy? - just trying to understand production fluctuation.

 

[ThaiTaffy]

So I've solved it but it was weird, somehow the AiO had managed to set itself to utility first no idea why that limits it's solar production. I'll be rewriting my firmware for my monitoring and removing all the modbus writes to be safe.

That looks scary...

Yep it was certainly worrying me.

It can be one panel that is giving your trouble - will you have ability to have mc4-mc4 lead to skip one panel and see the results?
How many panels do you have? - as your MPPT charger starts at 120V Voc, then at 380W 4 panels in my opinion shall be a minimum in a string.

This unit actually starts at 30v so I only have 2 panels working at 60.8vmp it's only a ups for the fridge and my server Rack but I generally dump extra power into fans around the house

I had similar issues with my easun charger that I am investigating, but it restarts the produced power after it is disconnected from PV and battery for a 5 minutes.

Check the settings if it's acting similar to mine maybe something's askew

btw were the days from 27th to 30th cloudy? - just trying to understand production fluctuation.

Those days were ok but it's monsoon season, as I said I'm only using 2x 380W panels so around 630W isn't bad, just annoyed now I went and ordered new mc4 connectors and stressed myself out for essentially nothing.
No idea how the settings got changed I don't remember resetting the unit, I'll leave the monitoring disconnected for now untill I can sort out the modbus I don't think I'll be adding modbus writes to any further projects that can induce fire.

 

[Mattb4]

So I've solved it but it was weird, somehow the AiO had managed to set itself to utility first no idea why that limits it's solar production. ...

What is your charging source priority?

 

[ThaiTaffy]

What is your charging source priority?

While it was messed up it was grid+solar now it's just solar only.

I was trying to turn off the display backlight to video the PV input and load on the device incase I had to warranty with Powmr and noticed all the settings were messed up. I've set notifications on my phone now if any settings are changed so I'll know if it happens again in the future but seems very weird.

 

[JWLV]

That is indeed strange. But I'm glad you found the problem. I wonder how the settings got changed.

 

[ThaiTaffy]

That is indeed strange. But I'm glad you found the problem. I wonder how the settings got changed.

Thanks, yes it's very confusing I powered down the system earlier today to see about installing the battery breaker into an enclosure and with no DC or AC and the system powered down the settings didn't revert and stayed at my last known config.
The only thing that I could have possibly done is some form of sleep walking.
I have been known to wake up with lots of random YouTube subscriptions so I wouldn't put it past me.