After an outage, the system remains in backup mode

[buenoshun]

When I have a grid outage, my tesla gateway2 switches to backup mode and runs from battery and solar, which is fine.
When the grid comes back, the system remains in backup mode. I dont know how long, because I loose my patience and turn the battery off and on, then the app shows the grid is back on. But then the solar is not charging, for a while, so I turn that one off and on too. So there is a time when the grid is back on, but the gateway still thinks it is still off, the app shows grid down. How long does it last, does it really require a manual reset? Is it a bug or a feature?

 

[wjgjr]

How long are you waiting? I would give things at least 10-15 minutes. Different installs seem to have different behaviors, but for us, if there is an outage - even brief - it takes at least 5 minutes for the system to reconnect to the grid. If solar was turned off due to the outage (which is typical in our system where we use backup-only mode), the solar will not start up for another 5 minutes. All told, that means for every brief outage, we have a minimum of 10 minutes (and it is perhaps more like 11-12) where solar is off.

 

[buenoshun]

It might have been around 5 minutes I guess. Happened a few times.
Im worried that if it fails to reconnect permanently, then the battery would drain without me noticing it.
The app fails to provide notifications of outage. It is an android issue, another app the signal messenger had the same problem.

 

[sorka]

How long are you waiting? I would give things at least 10-15 minutes. Different installs seem to have different behaviors, but for us, if there is an outage - even brief - it takes at least 5 minutes for the system to reconnect to the grid. If solar was turned off due to the outage (which is typical in our system where we use backup-only mode), the solar will not start up for another 5 minutes. All told, that means for every brief outage, we have a minimum of 10 minutes (and it is perhaps more like 11-12) where solar is off.

When I have outages, the app shows the grid back up within a second of the grid actually coming back up. I've tested this myself by turning off the main service breaker and then running in backup mode for a while before turning it back on.

 

[jrweiss98020]

It might have been around 5 minutes I guess. Happened a few times.

That's normal. The gateway waits ~5 minutes after power is restored to ensure it is stable. That protects line workers, preventing feedback to the grid if they get an intermittent connection while working.

 

[wjgjr]

When I have outages, the app shows the grid back up within a second of the grid actually coming back up. I've tested this myself by turning off the main service breaker and then running in backup mode for a while before turning it back on.

Yeah - that is why I said different installs have different behaviors. Some systems reconnect right away, but others wait 5 minutes. I think somebody noted it had to do with an NEC rule that applies to some setups, but I admit to not knowing all the details. It is just something to be aware of that it can be configured that way.

This is a great example of where Tesla does a terrible job of documentation - they should be telling customers what to expect in an outage so they can know what to expect and when something is actually going wrong. I had to figure it out by testing for myself and reading about the behavior online. Hopefully that is all that is going on with OP and there is not a bigger issue.

 

[jjrandorin]

Yeah - that is why I said different installs have different behaviors. Some systems reconnect right away, but others wait 5 minutes. I think somebody noted it had to do with an NEC rule that applies to some setups, but I admit to not knowing all the details. It is just something to be aware of that it can be configured that way.

This is a great example of where Tesla does a terrible job of documentation - they should be telling customers what to expect in an outage so they can know what to expect and when something is actually going wrong. I had to figure it out by testing for myself and reading about the behavior online. Hopefully that is all that is going on with OP and there is not a bigger issue.

OP should simulate an outage, wait 5-10 minutes and turn the power back on, then not touch anything and see how long it takes the equipment to sync back. If the OP says "it might have been about 5 minutes" but they know it didnt come back on, 5 minutes is a LOONG time if you are staring there at an app waiting for something to happen (watched pot and all that).

I would bet that you are correct, and that it will sync back in 5 minutes when OP simulates it and doesnt touch it.

 

[zƬesla]

Where I am at, a 1-sec outage results in using the PWs for 5-min. App shows grid being out the whole 5-min. As mentioned this is the required NEC profile regionally.

 

[SMAlset]

Yeah - that is why I said different installs have different behaviors. Some systems reconnect right away, but others wait 5 minutes. I think somebody noted it had to do with an NEC rule that applies to some setups, but I admit to not knowing all the details. It is just something to be aware of that it can be configured that way.

This is a great example of where Tesla does a terrible job of documentation - they should be telling customers what to expect in an outage so they can know what to expect and when something is actually going wrong. I had to figure it out by testing for myself and reading about the behavior online. Hopefully that is all that is going on with OP and there is not a bigger issue.

They do tell you. Owners should check out the Energy Support area on Tesla’s site if they haven’t already.

Customer and Product Support | Tesla Support

Find answers and learn about our products, home charging installation, warranties, leasing, lending, trade-ins and more.

www.tesla.com

See the section on “Best Practices During Power Outage” under Powerwall.

 

[SMAlset]

We’ve only had a 23 second outage since install that occurred at night so no solar anyway being generated. Did notice a flicker which we understand is normal in that situation, otherwise would not have realized power had gone out.

 

[wjgjr]

They do tell you. Owners should check out the Energy Support area on Tesla’s site if they haven’t already.

Customer and Product Support | Tesla Support

Find answers and learn about our products, home charging installation, warranties, leasing, lending, trade-ins and more.

www.tesla.com

See the section on “Best Practices During Power Outage” under Powerwall.

I'm not sure that was available when my install was done (wayback machine suggests it is newer, though it could have changed URLs) so it is good (though I still do not consider this a full substitute for tailored customer documentation.)

And, in any case, from what I can see, the section you referenced (Best Practices During Power Outages | Tesla Support) does not address the 5-minute wait when power restores or the 5-minute wait after restore for solar to resume. It only notes that you won't get a notification for outages under 5 minutes.

 

[cali8484]

When I have outages, the app shows the grid back up within a second of the grid actually coming back up. I've tested this myself by turning off the main service breaker and then running in backup mode for a while before turning it back on.

Inverters that connect the utility grid must comply with IEEE 1547 standard which specify that after an inverter shut off due to grid disturbance (e.g. grid outage/disconnect/voltage too high or low) a fixed (5 minutes) or variable (between 0 and 5 minutes) delay to restart generation after grid presence is detected by the inverter. Most grid interactive inverter manufacturers defaults to fixed 5 minute delay to comply with IEEE 1547 and there is no minimum shut off (e.g. grid outage) duration required to apply the restart delay.

So, I suspect your inverters never actually shut off (i.e. no solar production) in your tests because your PW was able to transfer to/from the grid fast enough so the inverters only see short transients that they just ride through (according CA Rule 21) instead of shut off.

 

[sorka]

Inverters that connect the utility grid must comply with IEEE 1547 standard which specify that after an inverter shut off due to grid disturbance (e.g. grid outage/disconnect/voltage too high or low) a fixed (5 minutes) or variable (between 0 and 5 minutes) delay to restart generation after grid presence is detected by the inverter. Most grid interactive inverter manufacturers defaults to fixed 5 minute delay to comply with IEEE 1547 and there is no minimum shut off (e.g. grid outage) duration required to apply the restart delay.

So, I suspect your inverters never actually shut off (i.e. no solar production) in your tests because your PW was able to transfer to/from the grid fast enough so the inverters only see short transients that they just ride through (according CA Rule 21) instead of shut off.

That could be. If it's sunny, the inverter is typically on through the entire test including when reconnecting to the grid. If the powerwalls somewhat full, the inverter might be signaled to shut off by the raised line frequency. In that case, the inverter might be off when I turn the main service breaker back on.