Powerwall 2 + UPS Connundrum - and solution

[jjrandorin]

It's not dependent on the solar inverter but other items you have that are frequency sensitive. So it could be lighting, your microwave, UPS etc. Make yourself a list of items that don't behave properly at 65 hz and tell Tesla what is not working. They should then drop it to something more reasonable (ie for me it was 62.5 hZ). I still have some light switches that don't like 62.5 Hz but can live without those so NBD.

What @aesculus said

Tesla is likely to ask you what things are not working, so have a list ready. They are fully aware of this issue, so will probably set it to 62.5Hz even if your inverter supports lower though, but 62.5Hz works with "most" things

 

[Blindsay]

It's not dependent just on the solar inverter but other items you have that are frequency sensitive. So it could be lighting, your microwave, UPS etc. Make yourself a list of items that don't behave properly at 65 hz and tell Tesla what is not working. They should then drop it to something more reasonable (ie for me it was 62.5 hZ). I still have some light switches that don't like 62.5 Hz but can live without those so NBD.

Thanks, just trying to understand the process more. But why is it 65hz and not just 60 in the first place Is what im trying to understand. Is that how it tells the solar inverter to stop sending power when the powerwall is fully charged?

 

[jjrandorin]

Thanks, just trying to understand the process more. But why is it 65hz and not just 60 in the first place Is what im trying to understand. Is that how it tells the solar inverter to stop sending power when the powerwall is fully charged?

The method of turning off (or in newer systems, turning "down" before turning off) the solar production is to raise the power frequency from the default 60Hz in the US to a higher number. 65Hz is pretty much guaranteed to turn any PV system off. Why they dont require installers (theirs or others) to submit / set this up to the number that turns off that specific equipment, vs the blanket number, is anyones guess.

 

[aesculus]

Thanks, just trying to understand the process more. But why is it 65hz and not just 60 in the first place Is what im trying to understand. Is that how it tells the solar inverter to stop sending power when the powerwall is fully charged?

This might help you. Rule 21 inverters will shut off at 62 hz. No need to go to 65 hz,

How California’s Rule 21 inverter requirements expand grid capacity, limit energy (revenue) generation

A multi-year effort has been ongoing in California to update technical requirements for connecting Distributed Energy Resources (DER) to the grid, known as Rule 21. The experience of Germany was cited as one reason to take action. In Germany, significant grid destabilization problems arose when...

solarbuildermag.com

 

[Blindsay]

The method of turning off (or in newer systems, turning "down" before turning off) the solar production is to raise the power frequency from the default 60Hz in the US to a higher number. 65Hz is pretty much guaranteed to turn any PV system off. Why they dont require installers (theirs or others) to submit / set this up to the number that turns off that specific equipment, vs the blanket number, is anyones guess.

This might help you. Rule 21 inverters will shut off at 62 hz. No need to go to 65 hz,

How California’s Rule 21 inverter requirements expand grid capacity, limit energy (revenue) generation

A multi-year effort has been ongoing in California to update technical requirements for connecting Distributed Energy Resources (DER) to the grid, known as Rule 21. The experience of Germany was cited as one reason to take action. In Germany, significant grid destabilization problems arose when...

solarbuildermag.com

Thank you both. I have a ticket open now with tesla and they have already escalated to the folks who can make the change. Hopefully it is below 63hz as thats the max for my UPS. The microwave also hated the 65hz.

I have all my networking gear on a UPS as well and last night we lost grid and then it just ran down my ups and all the networking gear went down despite having a ton of power in the powerwalls so it will be nice to get that resolved

 

[jrweiss98020]

Ask for 62 or 62.5 Hz so it doesn't trigger any UPS you may have installed. Computer power supplies are tested and certified to 63 Hz. Some old/cheap clocks that use phase synchronous motors will run a bit fast while the freq is raised.

 

[kbaybob]

I just discovered this string, and find it very helpful. We have 7 powerwalls and have had various issues with the switchover. The installer lowered their max line frequency to 62.5Hz, but my Cyberpower 1500s still have been having problems with immediately tripping offline during the switchover. Also, our Thermador induction cooktop will not work at 62.5Hz. Once the powerwalls get discharged enough to settle down at 60Hz, the induction cooktop will again work but requires a breaker reset. As for finding a UPS that will operate up to 65Hz, I can't find the data on them easily in the sales pitch on Amazon. One of the ones mentioned is no longer available. An easy answer might be to only charge the powerwalls to 90%, but I have not found a way to set the upper charge limit. Up until a recent testing period we have had them always on standby at 100% charge, and then set them to operate based on proposed TOU rates, but they still charge up to 100%. Can anyone tell me how to set an upper charge limit to keep them at a max of 90% charge?

 

[miimura]

Can anyone tell me how to set an upper charge limit to keep them at a max of 90% charge?

This is not an available feature.

Most UPS units will not transfer to battery at 62.5Hz, so having the PW system set for that maximum frequency is the generally accepted solution. If your UPS does not support its loads while the PW system is transitioning from On-Grid to Off-Grid mode, it is faulty, needs a new battery, or is overloaded.

There is not a solution for appliances that do not accept 62.5Hz. It appears that you will have to power cycle the induction cooktop when the frequency is back to 60.0Hz, whether on-grid or off-grid.

 

[lodar]

As for finding a UPS that will operate up to 65Hz, I can't find the data on them easily in the sales pitch on Amazon.

I initially bought Eaton UPSs because they will not trigger until 70 Hz. No guarantees that whatever is behind it won’t not trip first though.

https://www.eaton.com/content/dam/e...5px-ups/eaton-5px-ups-manual-northamerica.pdf

APC Smart-UPS “On-Line” are double conversion that can clean up the frequency and voltage without engaging the battery. They have come down significantly in price that I would get these going forward.

APC Smart-UPS On-Line, 2200VA, Rackmount 2U, 120V, 6x 5-20R+1x L5-20R NEMA outlets, SmartSlot, Extended runtime, W/ rail kit - SRT2200RMXLA | APC USA

 

[aesculus]

but my Cyberpower 1500s still have been having problems with immediately tripping offline during the switchover.

FWIW my PWs are set to 62.5 Hz and my Cyberpower 1500VA works just fine during the cutover.

 

[jrweiss98020]

I initially bought Eaton UPSs because they will not trigger until 70 Hz.

Problem here is that many electronics - including PC power supplies - are certified and tested only to 63 Hz. Extended use at 70 Hz may cause them to fail.

 

[miimura]

I was just bitten by this "feature" since I never bothered to ask Tesla to turn it down. I pre-emptively turned on grid charging this morning, so when the power went out this afternoon, the batteries were at 100% and went straight to 65Hz. Luckily, my wife was cooking and ran down the Powerwalls to 95% before the most important UPS (the one that powers the Internet stuff) ran out of battery. I opened a case with Tesla Energy Support and hopefully Tesla can make this adjustment to 62.5Hz before I have the next outage. It's also lucky that I just replaced the battery in that UPS unit two weeks ago. The old battery never would have made it through that duration.

 

[ai4px]

I was just bitten by this "feature" since I never bothered to ask Tesla to turn it down. I pre-emptively turned on grid charging this morning, so when the power went out this afternoon, the batteries were at 100% and went straight to 65Hz. Luckily, my wife was cooking and ran down the Powerwalls to 95% before the most important UPS (the one that powers the Internet stuff) ran out of battery. I opened a case with Tesla Energy Support and hopefully Tesla can make this adjustment to 62.5Hz before I have the next outage. It's also lucky that I just replaced the battery in that UPS unit two weeks ago. The old battery never would have made it through that duration.

I'm not using Tesla power wall, but rather I have a SMA sunny island off grid system. My system goes to 62hz to stop solar production. I'm baffled why Tesla would choose 65hz? Anyone know? Is there a good reason?

 

[jboy210]

I'm not using Tesla power wall, but rather I have a SMA sunny island off grid system. My system goes to 62hz to stop solar production. I'm baffled why Tesla would choose 65hz? Anyone know? Is there a good reason?

I was told it was told it was hold over for older systems that did not shutdown at lower Hz. When I called to change mine, they asked questions about all the equipment I had and in 3-4 weeks changed the frequence rise to 62.5 Hz when PWs are full.

 

[RKCRLR]

I was told it was told it was hold over for older systems that did not shutdown at lower Hz. When I called to change mine, they asked questions about all the equipment I had and in 3-4 weeks changed the frequence rise to 62.5 Hz when PWs are full.

That's interesting. I think my old string system has less than 1 Hz tolerance before it shuts down.

 

[ai4px]

That's interesting. I think my old string system has less than 1 Hz tolerance before it shuts down.

FWIW, grid tied inverters have a range from like 59.8hz to 60.5hz. Ouside of that they won't sync with the grid and start a 300 second reconnect timer. But you can reprogram them to have a wider range. My SMA sunnyboys were delivered as grid tied, but I contacted SMA and they gave me a grid guard code to switch them to OffGrid60 mode. Now they run 100% up to 61hz, and taper from 61-62hz The older SolarEdge inverters could be crudely controlled with digital inputs but the newer HDwave will do frequency shift power control.

Also, I don't have time to look it up, but many grid modes (ie for Hawaii or CA) will allow excursions beyond 60.5hz without requring the 300second reconnect delay.

Just general info, hope someone finds it helpful.