Energy meter is still showing negative L1 power consumption (started at 1.07):
This only seems to happen at lower loads, say less than 300W. Very oddly, if I increase the load, it will go positive, but then L2 goes negative. Situation reverses itself within seconds of removing the load.
Suspect this is impacting the ESS Grid setpoint functionality due the to the artificially low sum of phases.
What is your grid setpoint running ESS?
L1 + L2 = grid setpoint
Negative power legs are allowed with split phase, because of the imbalance current flowing through neutral. As long as they sum to your grid setpoint, all is well.
The “muliphase regulation” can disable this effect, but it is not recommended for efficiency reasons.
Like this (my grid setpoint is 200W):
100W. Odd that I first starting seeing this at 1.07, I don’t recall seeing it at 1.06.
My paranoia is that its feeding power back into the grid (negative wattage), which I’m not legally allowed to do.
Note quite sure I understand imbalance current, since each leg is fed by a separate inverter. Shouldn’t each inverter just provide what is needed for that leg? Only key is that they keep 180 degrees out of phase with each other - don’t understand why the current has to be balanced between them.
Actually sounds like “Multiphase regulation - individual phases” is exactly what I’m looking for since I can NEVER feed power back into the grid. Thanks!
I have an EM530 grid meter, so I don’t think the Victron meter firmware is the issue.
For others following along, this is a USA split-phase power topic.
I totally understand your desire to not feedback to the grid, but even with a meter, it isn’t physically possible to be fast enough to prevent sudden load changes from pushing power out. It is typically about one second, which may very well be too much.
The utility meter only sees 240V, the neutral is passed through.
Which is why L1+L2 = grid setpoint and one of them can be negative.
From the utility meter’s perspective, they can only measure the net power in or out at 240V.
Strictly speaking, you are exporting L1 to your utility transformer, where it comes back through the neutral conductor. You are not exporting to the grid, but you are to your transformer on the pole or on the ground.
Thanks for the explanation.
So as long as L1+L2 is positive, there is no export. That feels better.
Just to clarify: Since its coming back from the pole via the neutral line, and neutral is tied to ground at my main breaker box, the L1 negative power is essentially be shunted to ground? Or is the L1 negative power offsetting the L2 requirement using the transformer as a “gateway”?
So much to learn…
The fact that neutral is bonded to ground in the main panel is totally a separate concept, having to do with safety. All neutral wires in your house and back to the utility transformer are current carrying conductors, and that’s normal. Your ground wiring is normally NOT current carrying, but exists to complete the circuit in the event of a fault. Finally, “earth ground” does not normally carry any current either. Bonding to neutral in the panel and into the earth with a ground rod makes everything metal safe to the touch.
If you need more education, you can spend literally days reading about grounding at diysolarforum.com. Hope this helped.
