Difference between inverter kWh output # and meter output #?

[silversaver]

Why all this discussion of TED5000? The first post in this thread shows it agreeing within Poco meter within 1%. Is there actually any evidence of a problem? The higher energy output reading from the inverter could be calibration, or voltage drop, but the system is performing well even by the lower readings. Given the very hot temp that big inverter needs to run, I wouldn't be surprised if there was some calibration drift as a result.

inverter vs. POCO meter isn't 1% different.

yes, you got the point. After system completed, you get more posts on output from different meters, max out inverter in cloudy day.... what's next?

[sensij]

Why all this discussion of TED5000? The first post in this thread shows it agreeing within Poco meter within 1%. Is there actually any evidence of a problem? The higher energy output reading from the inverter could be calibration, or voltage drop, but the system is performing well even by the lower readings. Given the very hot temp that big inverter needs to run, I wouldn't be surprised if there was some calibration drift as a result.

[Sunking]

Well, it uses those plus a module that plugs into an outlet inside the house and the wires from the TED box are connected to the same breaker that controls that same outlet.

I don't think you are getting the big picture. You are going to have losses, end of story.

It is just the physics of how electric energy flows from one point to another. Current is equal at two nodes, but voltage is not. You will always loose voltage traveling from the source to the load. If your TED is getting its voltage reference at a wall socket then you are going to see some significant differences or in this case errors. You cannot measure current at one point and voltage at another point and expect any accuracy.

For a solar system there are 3 points in which you want to measure power.

1. The direct output of the Inverter.
2. POCO Meter Facility Side they monitor, bill, and meter you for.
3. Your Home Main Breaker Panel Main Service Breaker.

[bcroe]

Those are Current Clamps, not power or voltage.

Yea, they are in the right place for current, but have nothing to do with voltage.
Sounds like some research into the 3 voltage sensing wires could solve the
problem. If you connect next to the meter, they will ten to agree with the meter.
Extended to the inverter output terminals, will tend to agree with the inverter.

Bruce Roe

[HX_Guy]

Those are Current Clamps, not power or voltage.

Well, it uses those plus a module that plugs into an outlet inside the house and the wires from the TED box are connected to the same breaker that controls that same outlet.

[Sunking]

No, both TED clamp sets are inside the main service panel.

The clamps for the house end...

Those are Current Clamps, not power or voltage.

[silversaver]

I was looking at the online figures, not the LCD on the inverter itself. I would assume they should be the same, no?

BTW the SolarEdge inverter is reporting an AC voltage of 245.16V while the TED5000, which is inside the main service panel, is showing 121.3V (242.6?). So that's about a 1.1% loss? The run is only about 15 ft, is that normal?

I can take a multimeter to it later and check actual voltages, but that's what I was able to gather quickly.

Then you are not getting a real output from inverter. Those non-compliance meter are off espcially those monitoring from inverter manufacture... they tend to show higher output just like Enphase. I'm not sure with Solaredge, but you can always check for yourself.

[Sunking]

BTW the SolarEdge inverter is reporting an AC voltage of 245.16V while the TED5000, which is inside the main service panel, is showing 121.3V (242.6?). So that's about a 1.1% loss? The run is only about 15 ft, is that normal?

Maybe, maybe not but sounds real good. The loss is a product of current flowing through resistance. So it depends on how much current is flowing, and the size and distance of the wiring.

This goes back to what I said earlier about measuring with a micrometer, mark it with chalk, cut with an ax, a make it fit with a sledge hammer. Here is what you are running into. Your POCO meter is measuring power at its node point which means at its physical location. Your meters are in a different location along the electrical path. Current is the same at the different points, but not the voltage and power.

At your Inverter say you have 246 volts @ 40 amps (9840 watts) leaving. At the POCO meter it sees 241 volts @ 40 amps (9640 watts) from your inverter, a difference or loss of 2%. Both meters are correct. Fact is you loose power at every stage. You loose power in your wiring between the panels and inverter, in the Inverter converting DC to AC, and you loose power between the Inverter and POCO Meter. There is nothing you can do about it except to try to minimize it by proper design. You cannot eliminate losses, all you can do is try to minimize them. The lower the loss you strive for, the more expensive it gets. To go from 3% to 2% gets real expensive real fast.

[HX_Guy]

If that is in fact how TED measures the voltage, then it is invalid. While in theory the halves should be equal in practice they are not.

Looks like it was a settings thing, and I just changed the "Display Voltage" from 120V to 240V.



Interesting thing is that it matches what the SolarEdge online portal shows almost exactly. SolarEdge shows 243.86V and TED shows 243.4V.

EDIT: And here's another thing. The TED has 3 wires, black, white and red, and in the installation instructions it say stop use the black and white, and cap off the red. But now looking at the settings, it can be set to 120V (WHT/BLK), 240V (WHT/BLK) or 120V/240V (WHT/BLK/RED). So perhaps I should connect that red wire to a breaker on the opposite phase?

[HX_Guy]

No, both TED clamp sets are inside the main service panel.

The clamps for the house end...



The clamps for the solar end...

[Sunking]

That is an interesting point; inverter running at 240 VAC but TED plugging into 120 VAC.

If that is in fact how TED measures the voltage, then it is invalid. While in theory the halves should be equal in practice they are not.

[bcroe]

I was looking at the online figures, not the LCD on the inverter itself. I would assume they should be the same, no?

BTW the SolarEdge inverter is reporting an AC voltage of 245.16V while the TED5000, which is inside the main service panel, is showing 121.3V (242.6?). So that's about a 1.1% loss? The run is only about 15 ft, is that normal?

I can take a multimeter to it later and check actual voltages, but that's what I was able to
gather quickly.

That is an interesting point; inverter running at 240 VAC but TED plugging into 120 VAC. So
the TED knows to double the voltage for correct power. But any imbalance between the 2
120V halves (caused by imbalanced loading in the house and other things) will shift the
Neutral voltage between the halves, introducing an error.

Guess bridging a 240 variac across the inverter output leads and connecting the TED to a
center point could take the N imbalance out of the picture, and allow a chance to fine tune
accuracy. But unless the variac was connected to the inverter terminals, the adjustment
would only be precise at a particular output level. And this assuming the variac doesn't
introduce a power factor error.

Is the TED in that box the POCO padlocked?
Bruce Roe

[HX_Guy]

The inverter will shows the highest number since that's where the energy produced. POCO meter is the one it actually count.

I have Locus monitoring + TED 5000 as well, but the report aren't that far off. Locus monitoring is compliance with ANSI 12.20 class revenue-grade power-meter. The actual reports are less than 2% off comparing with inverter's output (by looking at inverter's output LED screen). TED 5000 report are like about 5% off.

OP mention the solaredge inverter output at 53.38kWh, I'm not sure if he is looking at the output from inverter's LED screen or his solaredge monitoring software.

I was looking at the online figures, not the LCD on the inverter itself. I would assume they should be the same, no?

BTW the SolarEdge inverter is reporting an AC voltage of 245.16V while the TED5000, which is inside the main service panel, is showing 121.3V (242.6?). So that's about a 1.1% loss? The run is only about 15 ft, is that normal?

I can take a multimeter to it later and check actual voltages, but that's what I was able to gather quickly.

[HX_Guy]

Edit: since no one has really said it... given the history of this system, it wouldn't hurt to check for hot spots in the connections between the inverter and the meter, just in case some power is being lost. A fun use of that camera the op just bought.

I gave the thermal camera a look but honestly not even sure what I'd be looking for. I can't open up the meter box or the disconnect anymore (POCO put their lock on it) so everything look "cool" through the camera, I guess that's normal.

I kind of wanted it to check the house inside for any air leaks to make sure the insulation is good, maybe it'll be more useful for that.

[HX_Guy]

That theres something funky in your KWH reporting software....

As was mentioned by sensij, I put up numbers that the TED5000 was reporting, which seems very accurate to the POCO meter. You seem to like to bust my balls for some reason.