I always suspected that the Tesla app was over-estimating my solar output, as the home usage graph always had a slight bump up centered on solar noon. (Home usage = PoCo - Solar)
This weekend I opened up the panel and checked with my Fluke.
The actual situation is more complicated - the Current Transformer is only on one leg of the inverter output, so it's being 2x'ed in the gateway. I thought that was reasonable, but it does seem there is a balance offset, and for accuracy you would need to put both leg wires through the CT (one the opposite direction to the other). Then the 2x setting could be removed.
So what I'm seeing in the app right now is 2x of one leg that is slightly higher than the other. Not a huge deal, at the end of the month it's the electric company that uses their numbers. For automation purposes, I can use a rule that reads when I start to export at the gateway, which is a true 2 leg CT, to start EV charging.
This weekend I opened up the panel and checked with my Fluke.
The actual situation is more complicated - the Current Transformer is only on one leg of the inverter output, so it's being 2x'ed in the gateway. I thought that was reasonable, but it does seem there is a balance offset, and for accuracy you would need to put both leg wires through the CT (one the opposite direction to the other). Then the 2x setting could be removed.
So what I'm seeing in the app right now is 2x of one leg that is slightly higher than the other. Not a huge deal, at the end of the month it's the electric company that uses their numbers. For automation purposes, I can use a rule that reads when I start to export at the gateway, which is a true 2 leg CT, to start EV charging.