If you have a whole-house backup the leads at the main breaker panel supply power to the house whether the grid is up or down so monitoring would continue when the grid is down (i.e. leave the clamps where they were)
M said: Would be nice of Sense to come up with a 3 pairs of clamps solution (or more, so they can take care of partial backup too).
I’m not sure it’s necessary. I have the Sense probes on the combined Solar/Powerwall output to the essential loads breaker and Sense can’t tell the difference between Solar and Powerwall energy so it could monitor through an outage. My Sense is connected to the essential-loads panel but I never tested if it would continue to identify devices in an outage.
I’ll kill the mains and test that assertion when I finish up the remodeling chores staring me in the face.
Ok, my clamps were effectively on what is now the mains side of the gateway, so I think I need to move them on the other side of the gateway, effectively breaker side… Glad to hear that this should work.
I guess to keep the configuration exactly the same as before, I could run solar + mains (the matching phases) into the mains clamps, and then solar in the solar clamps.
My installation of Solar and Powerwall 2 are complete.
Now, I cannot complete the solar setup in the Sense app, when ask to turn off the inverter, it never detects it as “off” and fails setup.
What am I missing?
Hi Oscar,
I just did the same this morning. I think you need to make sure that your solar is generating and that your powerwalls are off before starting the setup…
That worked for me…
Hey Tom,
If your CT were where you show, then Sense should stop working when you are in backup mode, no? I’ve put my clamp on the other side of the gateway relays, ie the black and red wires near the solar clamps and going to the panel.
matthieu:
If you put the main CTs on the lower pair of black/red wires, you’re measuring the grid plus solar/powerwall; not what I would want.
For a whole house backup the point I indicated in yellow is the grid entry point. When Tesla converted my installation to partial they moved their CT and mine to the new main panel at the grid entry point.
As I said, I haven’t tested Sense monitoring when the grid is down; there is enough data available but I don’t know what Sense does.
So my historical setup, prior to the powerwall, was measuring mains (which is effectively mains+solar) and solar.
Above (where you show the historical location) or below is actually equivalent provided you have the main clamps around both panel supply and solar supply for each phase. I was thinking above the grid isolation relay would not measure anything if grid is off (as this part is unpowered), but thinking about it, in that case, the consumption from the panel matches exactly the power provided by the solar+powerwall feed, so the current seen on the main clamps would be 0 either way… so effectively it doesn’t matter.
For partial backup, I’m not sure how this would work…
Thanks all, The support team enabled my solar remotely (nice )
Now, when the Powerwall batteries are feeding the power to the house (and also getting charged by solar) I see that the house is consuming power from the batteries:
but this is technically incorrect as the house is only using a very low power:
Matthieu:
Without Powerwall the solar CTs monitor the solar output but the monitor point for the mains CTs can be between the meter and the solar merge (monitoring grid draw only) or between the solar merge and the main house breaker(monitoring the combination of grid and solar power).
I’ve attached a schematic of a whole house backup. N.B. red arrows indicate current flow, green ones indicate monitored current.
I have 2 solar systems and a PowerWall2. Everything is Solar City / Tesla. Images below show Tesla monitored current flow and Sense monitored current flow. Can you all see an obvious solution to this “delta”?
I too have a SolarCity installation.
The Tesla app screenshot exhibits an improbable situation: either the powerwall is feeding the house in the absence of a grid outage, or the house is charging the powerwall.
That happened to me when my system was first installed: the house appeared to charge the powerwall. After going through a couple levels of tech support, a software download to the powerwall resolved the issue.
I saw a similar issue when Tesla installed a new main breaker panel and moved the current transformers. Tesla CTs are directional and mine were installed flipped over. The installer told me that the orientation of the CTs is clearly labeled but the labels are sometimes wrong.
I can’t explain the Sense screenshot without knowing how the two solar systems are integrated but I can say that Sense sees solar and powerwall as a single, bidirectional source, At the moment my Sense says I’m sending 22 w to the sun
P.S. I wish my Sense could find as many devices as your’s does.
Thanks Tom. I probably should have added that the PW2 is setup in my configuration to use 20% of its capacity to feed the house daily during peak hours. Excess solar it directed to the grid. That is the situation during this screen shot.
I guess I was more interested in the math around what I think is true (Tesla) and what sense is monitoring. Either the Sense CTs are in the wrong location or the system is incapable of monitoring correctly because there aren’t enough of them. Right?
On the topic of devices; I just received a new monitor (warranty) and all those devices are HST110 plugs that are monitoring known devices. In 2 weeks sense has found 2 (our morning hot water pot for coffee & the rough pump for our irrigation system).
These screenshots look correct to me… That is, If you’re running in advanced - time based control, then this is what I would expect during peak hours.
At that time powerwall is generating enough to cover your house consumption so all of your solar generation can be backfed to the grid. Because of the clamp configuration, solar shows the aggregation of your actual solar generation and powerwall generation. In effect, on the next day while you recharge your powerwall, sense will show 0 solar even though it is generating, but it’s going straight to the powerwall, so 0 aggregated…
I guess I was more interested in the math around what I think is true (Tesla) and what sense is monitoring. Either the Sense CTs are in the wrong location or the system is incapable of monitoring correctly because there aren’t enough of them. Right?
As was said above the solar looks right but what seems off is the Sense estimate of the house load. Tesla says 2kW load while Sense saye 3.7 kW. I can’rt explain the dufference.
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