SMA Sunnyboy Secure Power workaround for Rapid shutdown

[sabersix]

I have SMA Sunny Boy 5000TL-US-22 inverter with SPS that was installed in 2015. If (when) this inverter dies, what are my options for replacement? Will I be forced to install optimizers in order to replace my inverter with current products?

[oregon_phil]

What is your Rapid Shutdown solution used for your current set up?

When I had my RMA-ed SMA inverter installed, I sat down with my county electrical inspector to see how the new inverter installation should be handled since my original inverter was installed under NEC 2014 rules and the new inverter was to be installed in 2018. In my county, the new inverter would be handled as a maintenance item and would be held to NEC 2014 rules. I suspect your installation would be the same, but only your local authorities would know for sure.

If you have the SMA 2014 rapid shutdown box, it runs independent of any communication with the inverter. It just has an e stop shutdown switch by your outside electrical service panel. And I bet you would then set the inverter DC parameter setting "Rapid Shutdown Mode" to off. But I'm not 100% sure since I don't have that exact setup.

[sabersix]

What is your Rapid Shutdown solution used for your current set up?

I do not have RSD. I have an external disconnect switch.

I guess I'll start looking for NOS like replacement on ebay...

[oregon_phil]

I bought a spare inverter last year. Prices were high and lead times were long if you could get your hands on an inverter. Getting a spare inverter isn't a bad idea. Switching out identical inverters is much simpler than installing a new inverter with slightly different wire routing.

I also kept a copy of known good firmware off of my current inverter just in case I need to load it onto my spare inverter.

[solardreamer]

NEC 2014 allowed a different rapid shutdown solution. SMA made a rapid shutdown box, SMA RAPID SHUTDOWN BOX 4 STRINGS 2014 NEC 690.12 COMPLIANCE, that worked with SMA secure power. My original solar installation used this 2014 rapid shutdown device. SECURE POWER DOES WORK WITH THIS RAPIDSHUTDOWN SOLUTION, but this solution is not allowed today. The downside is that the "4 string" device actually turned 4 strings into 2 parallel strings which turned my 3 MPPT inverter into a 2 MPPT inverter.

I RMA'ed my SMA inverter under warranty after about a year and decided to have TIGO TS4-R-O optimizers installed to help with winter shading. I have a TIGO TAP on the roof and CCA near the inverter. I have verified that this setup with not work with secure power.

SMA has an app note on how to use -41 inverters with Secure Power and TIGO TS4-R-O optimizers. search "Secure_Power_Supply_Operation_with_TS4-R-O.pdf"

The problem with this solution is that TIGO TS4-R-O optimizers are obsolete and are not available.

NEC 2017 pretty much killed Secure Power for rooftop installations.

TS4-R-O is obsolete but it seems used ones are still available https://youtube.com/playlist?list=PL...Z4mYSGSfO1wHSA.

[Bobodude]

Inverter update. It seems that SMA may have updated my inverter’s firmware. I found that there is now a 3rd setting under “rapid shutdown” that says “Shutdown + SPS”. It used to offer only ON or OFF. I set it to the new setting. To test it, I disconnected from the grid. I then flipped the SPS switch to “on” and the inverter then displayed “SPS Active”. I had about 600 w of solar power available at 8 am. I plugged in a 1/2” drill into the socket and it ran happily. I then turned off SPS and in about 10 secs, all of the string voltages went to zero. So I now have a secure power source for emergencies. Again, during this test I simulated a grid outage. Voltage on the inverter side of the 240vac disconnect Sw was zero thru the whole test. The anti-islanding was working as it should. From this, I contend the rapid shutdown will work as required by the NEC. And if I want to use the secure source, it will not reconnect to the grid to endanger lineman who may be working on the line. I would have to obviously be home to use this feature. So in the unimaginable chance my house caught on fire at that exact time, I would be there to shutdown the SPS effectively activating the Rapid Shutdown. Now how many inverters on the current market can do that?

[nomadh]

Inverter update. It seems that SMA may have updated my inverter’s firmware. I found that there is now a 3rd setting under “rapid shutdown” that says “Shutdown + SPS”. It used to offer only ON or OFF. I set it to the new setting. To test it, I disconnected from the grid. I then flipped the SPS switch to “on” and the inverter then displayed “SPS Active”. I had about 600 w of solar power available at 8 am. I plugged in a 1/2” drill into the socket and it ran happily. I then turned off SPS and in about 10 secs, all of the string voltages went to zero. So I now have a secure power source for emergencies. Again, during this test I simulated a grid outage. Voltage on the inverter side of the 240vac disconnect Sw was zero thru the whole test. The anti-islanding was working as it should. From this, I contend the rapid shutdown will work as required by the NEC. And if I want to use the secure source, it will not reconnect to the grid to endanger lineman who may be working on the line. I would have to obviously be home to use this feature. So in the unimaginable chance my house caught on fire at that exact time, I would be there to shutdown the SPS effectively activating the Rapid Shutdown. Now how many inverters on the current market can do that?

Great news to hear and thanks for the update. Does this mean we can buy new sunny inverters and still have emergency backup power?
funny how I delayed buying solar for years until I say the sunny sps option and now just a few years later they basically Outlaw it.
thanks

[solarix]

Its too bad that SMA's Sunnyboys are out of production until 3rd qtr 2023.... Supply chain issues with a microchip they say. I think they shut production down to do a redesign to solve the problem.

[FlyCloseToTheSun]

Thanks to the members in this post for giving me hope that I could gain SPS functionality. I have a SMA SB6.0-1SP-US-41 with Tigo TS4-R-F. Installed in 2020 was initially told SPS was not possible due to rapid shutdown requirements. Emailed SMA and got this reply.

"You can use the SPS in conjunction with the TS4-R-F, to do this you need to make sure of two things: Inverter needs to be on its latest firmware
Inverter needs to be set to "Rapid Shutdown Mode: Sunspec" with "Secure Power Supply On"
The SPS will work but only for the rest of the day that is activated, if the outage lasts more than 1 day it will not work for the next day, this is due to the TS4 modules design."
I've updated my firmware, contacted my Solar installer to change my inverter parameters and schedule SPS installation.

Registered just to post this!

[solardreamer]

Thanks to the members in this post for giving me hope that I could gain SPS functionality. I have a SMA SB6.0-1SP-US-41 with Tigo TS4-R-F. Installed in 2020 was initially told SPS was not possible due to rapid shutdown requirements. Emailed SMA and got this reply.

"You can use the SPS in conjunction with the TS4-R-F, to do this you need to make sure of two things: Inverter needs to be on its latest firmware
Inverter needs to be set to "Rapid Shutdown Mode: Sunspec" with "Secure Power Supply On"
The SPS will work but only for the rest of the day that is activated, if the outage lasts more than 1 day it will not work for the next day, this is due to the TS4 modules design."
I've updated my firmware, contacted my Solar installer to change my inverter parameters and schedule SPS installation.

Registered just to post this!

I guess that's better that nothing but it doesn't change the fact that SPS is effectively no longer available as the TS4-R-F has been replaced by the JMS-F and it does not support SPS.