Tesla Solar Panels & Inverter (no powerwall) with Neurio and two electrical panels

[shred86]

I have a Tesla solar panel setup (11.2 kW) with a single Tesla inverter (7.6 kW). A couple days ago Tesla installed a Neurio energy monitoring device but at times the indications are clearly wrong. The issues only seem to appear when the solar panels are producing energy but basically it will show my home is consuming 0 kW when there should at least be some usage and will also show that I'm producing/exporting more solar energy than my inverter is capable of. I've spent quite a bit of time troubleshooting and reading various threads on here and reddit, but I believe the problem comes down to the fact I have two electrical panels, a 200A panel (exterior, solar inverter breaker) and 100A panel (garage). I only have one meter with four lines coming off it with two going to the 200A panel and two going to the 100A panel. Here's a picture of the electrical diagram layout on the inside of my main panel which shows the meter (left side) with the two lines from the utility that are split into four to feed the two electrical panels. I overlayed how the Neurio device is setup with a CT clamp on all four mains, but are then combined using a splitter so it only occupies the CT1 and CT2 ports on the Neurio device itself. I didn't depict the voltage cable to the circuit breaker for the Neurio.

I've verified all the CT clamps are installed correctly and have experimented with changing the direction, but I'm not confident it's working properly. I believe the issue is when I'm producing solar energy, its being fed into my main 200A panel and if some of it starts exporting to the grid, I'm assuming some of that will flow into the 100A panel if there's an energy demand from my lights and outlets that the 100A panel feeds. The issue here is I think the Neurio is measuring the solar energy being exported from the 200A panel but also measuring some of that solar energy being imported into the 100A panel as being drawn from the grid (the 100A panel has no idea where that energy is coming from). Perhaps this is throwing off the CT1 and/or CT2 readings at the Neurio device?

That being said, anyone with a similar setup that has been able to figure out a way to resolve this? I contacted Tesla support but they told me I needed to wait 30 days for the system to calibrate...... Maybe they're right, but given that I can log directly into the inverter interface and see the same issue, I think it's the Neurio device that is just reporting bad data to the Tesla app/server.

 

[SMao]

I have simple setup, one 7.6kw inverter (no powerwall), 8.8kw solar panel, and only one 200A panel, and one Neurio meter with two lines (CT1 and CT2).

Still same problem, for example, during 1PM peak production, solar production 7.4KW, however, Neurio meter reported 12.6KW export, while the actual export is 12.6/2=6.3KW

The issue also happens during night time (no solar production), when the home consumption is 0.5KW, Neurio reported twice the actual value, which is 1KW.

Root cause should be at Neurio meter or inverter, and Neurio always reports twice the actual value

 

[shred86]

Interesting. My issue seems to be slightly different, although they're probably related. For example, right now I'm producing the max 7.7 kW for solar production and my home usage should be under 500-600W right now. However, I'm connected directly to the inverter and it shows Site Meter: 9,267W export which is obviously more than my single 7.6 kW inverter is capable of.

When I shut off the PV circuit breaker so I can just monitor what the Neurio is reporting, everything appears to be fine or as I would expect. I even checked each electrical panel at a time by disconnecting a set of CT clamps and the readings all make sense. However, as soon as I turn the PV circuit breaker on so solar is now providing power to the system, this is when I see these abnormally high export values.

 

[Donaldinc]

I have simple setup, one 7.6kw inverter (no powerwall), 8.8kw solar panel, and only one 200A panel, and one Neurio meter with two lines (CT1 and CT2).

Still same problem, for example, during 1PM peak production, solar production 7.4KW, however, Neurio meter reported 12.6KW export, while the actual export is 12.6/2=6.3KW

The issue also happens during night time (no solar production), when the home consumption is 0.5KW, Neurio reported twice the actual value, which is 1KW.

Root cause should be at Neurio meter or inverter, and Neurio always reports twice the actual value

This is the identical issue I am having, were you able to resolve and or fix this issue?

 

[SMao]

This is the identical issue I am having, were you able to resolve and or fix this issue?

I reported this issue more than 1 month ago, and Tesla is still working on it, nobody came to my house to fix it yet

 

[Donaldinc]

I reported this issue more than 1 month ago, and Tesla is still working on it, nobody came to my house to fix it yet

Can you confirm if this is just an aesthetic issue with the front facing app and that the back end is being reporting correctly via Tesla and utility company?

 

[SMao]

Can you confirm if this is just an aesthetic issue with the front facing app and that the back end is being reporting correctly via Tesla and utility company?

it's aesthetic issue with the app, and root cause is that neurio/inverter reports 2x the actual usage. Utility meter is not affected

 

[miimura]

I have simple setup, one 7.6kw inverter (no powerwall), 8.8kw solar panel, and only one 200A panel, and one Neurio meter with two lines (CT1 and CT2).

Still same problem, for example, during 1PM peak production, solar production 7.4KW, however, Neurio meter reported 12.6KW export, while the actual export is 12.6/2=6.3KW

The issue also happens during night time (no solar production), when the home consumption is 0.5KW, Neurio reported twice the actual value, which is 1KW.

Root cause should be at Neurio meter or inverter, and Neurio always reports twice the actual value

This is probably a configuration problem in the Tesla Gateway. On a 240V split phase circuit you can either use one CT and tell the Gateway to double the value or use two CTs. Yours is probably doubling the value when it shouldn't.

 

[Donaldinc]

This is probably a configuration problem in the Tesla Gateway. On a 240V split phase circuit you can either use one CT and tell the Gateway to double the value or use two CTs. Yours is probably doubling the value when it shouldn't.

This is a interesting yet effective solution that when i removed one of the CT clamps, everything appears to be normal. But if only going with 1 CT, will Neruio record all usage from both phase a and B or just one or the other? And which of the CT clamps should you not use?

 

[jgleigh]

1 CT can only record one phase. It doesn't know anything about the other one. Typically CTs are only doubled on solar circuits where you know the phases are balanced. The gateway configuration needs to be updated so it knows that CT has two phases and to remove the doubling setting.

 

[miimura]

This is a interesting yet effective solution that when i removed one of the CT clamps, everything appears to be normal. But if only going with 1 CT, will Neruio record all usage from both phase a and B or just one or the other? And which of the CT clamps should you not use?

The doubling should be turned off in your configuration. To accurately measure split phase power you must have two CTs. Single CT and doubling should only be used in PowerWall systems for measuring solar production, which is pure 240V.

 

[Donaldinc]

1 CT can only record one phase. It doesn't know anything about the other one. Typically CTs are only doubled on solar circuits where you know the phases are balanced. The gateway configuration needs to be updated so it knows that CT has two phases and to remove the doubling setting.

Do you have instructions on how to access the gateway configuration to update this?

 

[miimura]

Open a ticket with Tesla Energy and they can remotely fix the configuration.

 

[shred86]

I think there’s two issues going on here, but related since they both result in the Tesla app showing incorrect values. My original post I believe is just based on having two electrical panels, one 200A and one 100A with dedicated lines feeding into them from the meter. After a lot of experimenting, I’m pretty certain the issue is you can’t combine CT clamps using a Y splitter to measure two different panels when the CT clamps in one panel is measuring export while the other CT clamps in the other panel are measuring export. I think the solution is simple - don’t use Y splitters and just utilize the CT3 and CT4 ports on the Neurio. I’ve had a ticket in with Tesla for 3+ weeks now but still nothing.

The other issue is with the single electrical panel that is mentioned here where the reported values appear to be doubled, show 0 kW home consumption, or even show production at night when the sun has set. The latter two issues leads me to believe it’s more than just a configuration option in Neurio to double the reported values.

One thing I have noticed looking at photos from two different installs with this issue is they have two unknown black wires that feed into the voltage reference lines for the Neurio. Here’s a photo of someone’s setup that has this issue where you can see the black wire (highlighted with a green line) coming from Neurio connects to a push wire connector which then has a wire going to a circuit breaker and another black wire that is unknown. Same for the red and blue wire coming from Neurio. The voltage reference lines in my setup don’t have these extra black wires, and from the research I’ve done, they shouldn’t. The voltage reference lines should only connect to a circuit breaker that matches the phase of the CT clamp (black to CT1 and red to CT2… blue is not used and can just be combined with red). Also, these setups are solar panels with Tesla inverters only (no power walls). Anyone have any clue what the black lines might be for? I’m wondering if they’re throwing off the readings by providing a voltage reference that isn’t the correct phase.

 

[Donaldinc]

I think there’s two issues going on here, but related since they both result in the Tesla app showing incorrect values. My original post I believe is just based on having two electrical panels, one 200A and one 100A with dedicated lines feeding into them from the meter. After a lot of experimenting, I’m pretty certain the issue is you can’t combine CT clamps using a Y splitter to measure two different panels when the CT clamps in one panel is measuring export while the other CT clamps in the other panel are measuring export. I think the solution is simple - don’t use Y splitters and just utilize the CT3 and CT4 ports on the Neurio. I’ve had a ticket in with Tesla for 3+ weeks now but still nothing.

The other issue is with the single electrical panel that is mentioned here where the reported values appear to be doubled, show 0 kW home consumption, or even show production at night when the sun has set. The latter two issues leads me to believe it’s more than just a configuration option in Neurio to double the reported values.

One thing I have noticed looking at photos from two different installs with this issue is they have two unknown black wires that feed into the voltage reference lines for the Neurio. Here’s a photo of someone’s setup that has this issue where you can see the black wire (highlighted with a green line) coming from Neurio connects to a push wire connector which then has a wire going to a circuit breaker and another black wire that is unknown. Same for the red and blue wire coming from Neurio. The voltage reference lines in my setup don’t have these extra black wires, and from the research I’ve done, they shouldn’t. The voltage reference lines should only connect to a circuit breaker that matches the phase of the CT clamp (black to CT1 and red to CT2… blue is not used and can just be combined with red). Also, these setups are solar panels with Tesla inverters only (no power walls). Anyone have any clue what the black lines might be for? I’m wondering if they’re throwing off the readings by providing a voltage reference that isn’t the correct phase.

Regarding your question with the black wire, it's a split from an existing power source that goes into the push wire connector and using the same breaker to power both the source and the neurio. In your setup, it does not appear you have a power source that needs to be split. Do you have a picture of the other neurio push wire connector going to a different phase?

 

[shred86]

Regarding your question with the black wire, it's a split from an existing power source that goes into the push wire connector and using the same breaker to power both the source and the neurio. In your setup, it does not appear you have a power source that needs to be split. Do you have a picture of the other neurio push wire connector going to a different phase?

Ah that makes sense. My Neurio is connected to its own circuit breaker. Well, that answers that...

Perhaps it is just a configuration issue where the measurement is just being doubled at Neurio. If your grid export exceeds solar production (actual, not what’s displayed in the main page), then it would make sense that home consumption displays as 0 kW.

 

[jgleigh]

I think the solution is simple - don’t use Y splitters and just utilize the CT3 and CT4 ports on the Neurio.

I'm not even sure that will help. I have two separate CTs (Neurio and Gateway) and I also have the data errors. The app is doing something behind the scenes when it displays that data that isn't correct.

 

[jgleigh]

@shred86 Can you post pics of the app when you're having issues? Also, are you sure the CT clamps are all facing the correct direction? A backwards clamp can make imports look like exports and vice versa. I'm wondering if the CT clamps on your 100A panel might be backwards and so their consumption would like like additional exports.

 

[shred86]

Yeah, I checked the CT clamps multiple times and they are installed in the correct orientation. ”Source This Side” is facing towards the meter (i.e. power coming from the utility). I’ve also checked the voltage reference wires to make sure they correspond to the correct CT input, so the black wire is on the same phase as CT1 and the red wire is on the same phase as CT2.

The specific issues I’ve noticed in the app are:
- Solar production being higher than my inverter rating (pictured below). When this occurs, my home consumption is 0 kW. The solar production graphs are always correct though. This only seems to occur when there is not a high demand on home consumption (e.g. ACs not running, car not charging, etc.). If I turn on the AC and/or start charging my car, the values appear to be more realistic, although I have no idea if they are accurate. This only seems to occur when I’m producing solar energy. In other words, I never see solar production at night (which makes sense) but I also never see 0 kW of home consumption, it’s always indicating some consumption.
- Home consumption sometimes showing high values (e.g. 8 kW+) when the home usage should be less than 1 kW (ACs not running, car not charging, no appliances other then refrigerator running, everything else essentially off). This is even after it’s been several minutes and I can see the kW values changing slightly, so I’m pretty sure the Tesla app is being updated.
- Home consumption sometimes showing low values or even zero when the home usage should be much higher. Basically opposite of what I mentioned above. For example, right now I was showing 0.5 kW of home consumption and now it dropped to 0 kW when we have multiple appliances and devices running (picture below).

When looking at the Tesla inverter page, I can see the measurements from CT1 and CT2 being reported which obviously match what’s listed under “Site Meter” on the main inverter page. This value always appears to match what’s being reported for grid import/export in the Tesla app which makes sense. I flipped my solar inverter circuit breaker off when the issue above was occurring and it seemed to “fix” the issue confirming these problems only occur when solar production is provided. I also pulled the CT clamps off the 100A panel when this issue was occurring and that also seemed to have fixed the issue. This is what leads me to believe what I mentioned in my original post that when I’m exporting to the grid (e.g. AC not running, car not charging, etc… low energy consumption) and there’s electricity being consumed in the 100A panel (lights, outlets, etc.), the CT clamps in the 200A panel are measuring the grid export and the CT clamps in the 100A panel are measuring grid import (which is actually coming from the solar export), but the CT clamps are combined using a Y splitter as depicted above which I think is causing at least a part of my issue.

 

[jgleigh]

One last thing to check, are you sure both Phase A CT clamps are on Phase A, etc. It's very easy to get phases swapped around with these split panels. My subpanel breaker has the outputs reversed from everything else in the panel.

Also, is there a Neurio in the inverter? I'm not sure how that is reported w/o a Powerwall+. It would be interesting to see what that is reporting vs what the app is showing for solar production.