Hello, I am seeing data that doesn’t make sense.
Displays show that during the day that the mains are pushing more power to the grid than the solar panels are producing.
I have 2 solar systems, the older (Sunrun) appears to be working as expected, the newer system (Sunpower) shows only 2 watts. (The new system I Can’t monitor with the provided app due to Sunpower bankruptcy. Thats why I bought Iotawatt) An electrician verified with a current probe that the Sunpower system does not seen to be producing power tha he could see.
But, looking at the status and graphs they show more power being pushed to the grid than the Sunrun system is producing. So how can that be?
The Sunpower system is smaller and being monitored by AcuCT-H040-50 ct’s.
I connected a third AcuCT-H040-50 to input 14 monitoring a 200 watt bulb just as a sanity check on my configuration.
Having said all that could anyone explain why I would be seeing the discrepancy in readings?
Can you post a good resolution picture of the panel that shows the mains CTs and the CTs on the two PV systems?
Mains CT highlighted with blue line
very crowded panel
Sunrun CTs in lower rt corner of main panel
Sunpower CTs in lower rt subpanel
fyi Sunrun aka sunnyboy inverter
Thank you
There are connections spliced to the main feeds just below the mains CTs. What are those for? Are you sure those are not the feeds for the SunnyBoy? Can you put a CT on one of them and see what it reads?
That was the it! Apparently those devices are taps and is where the new Sunpower pushes power to the grid. I had never seen those before. The 20 amp breakers in the sub panel seem to only supply stand by power to their monitoring equipment.
Thank you so much for you help!
That’s good news. The Sunpower apparently is working and you have it monitoring.
Now for the bad news. I don’t believe feeding the Sunpower in like that is code. Granted it is common to tap the feeds into the incoming mains, but that is with a panel that actually has mains breakers. Your panel does not have a main breaker. Apparently it is upstream, possibly where the meter is.
The problem is that the panel is rated for 200A. Your mains are probably 200A as well and so limit the grid current that can get to the panel. However, in your case, the Sunpower inverter can add additional current and exceed the rating of the panel.
When mains taps are used to inject the PV, they are connected before the main breaker so that the panel is protected.
The proper way to connect the PV is to bring it in through a breaker at the bottom of the panel, as you see with the Sunrun connection. You might point this out to the electrician that installed it and ask that they correct it. I realize there is no remaining space at the bottom, but something can be moved to the branch panel to make room.
Adding the Sunpower to the bottom of the branch panel is also an option but the subpanel breaker in the main panel would need to be swapped with the breaker in the lower left.
Another option is if a mains breaker can be added to the main panel, but I suspect that would be pretty expensive.
If the installer does not believe it is a problem, you might bring this up with your electrical inspector.
I spoke with the elec inspector and he is ok with how things were done. ( he did inspect it)
there are fuses in the shut off box before the connection to the panel.