Grid Goes down; Multiple Inverters; Combine SPS into transfer switch

[khanh dam]

Ah... That makes sense. Thanks for that.

SPS is dead end technology because SMA no longer supports it On A RESIDENTIAL HOME which requires rapdi shut down. Only way to get around that is to build solar array on a pergola/detached unoccupied building so no rapid shut down is required. Building a structure big enough for your needs is at least another $6K DIY or $15K if you hire someone to make it.

SMA did release a white paper for using 2 nine volt batteries to power the transmitter while the grid was down a few years ago. If you are smart you might be able to figgure how to use with TIGO , but frankly thsi whole idea of paralleling all the outputs is a little daf. Just run the 5 SPS outlets to five parts of your home with extention cords as needed for the once a year emergency.

[khanh dam]

It seems like a lot of work for TIGO to keep validating whether or not their modules work with SMA SPS functionality so I would expect TIGO to stop this work for new inverters.

I called Tigo and their rep basically said we wont' test it because we dont' have the gear, but if you want to test it and let us know that would be great. In other words you are on your own with zero support.

[solarix]

"A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load." Doesn't work either. You can't run a microinverter into a load unless it is grid tied...Even if you are talking about battery backed inverters, you can't tie their outputs together.

[solardreamer]

Is there something you can buy to sync them so that you can essentially combine them into a 240v plug and plug it into a transfer switch?

I am not aware of anything plug-n-play for B). It's possible to convert each SPS output to DC then combine them to power another inverter kind of like a double-conversion UPS but is it worth doing?

[SoftwareDude]

B) No. Have you read the SMA inverter manual or searched the web regarding SPS functionality?

SMA inverters using the SPS outlet require GFCI outlets. One hint of abnormal loads or loads too high, the SPS outlet will shutdown. I have one and it is picky.

Combining SPS outlets from multiple inverter will not work. It will violate warranties. It won't work. Time to move on.

I appreciate the comment. I am not disagreeing with you, but I will decide to move on once I am satisfied that the answer is no. That's why I am asking a group of people and not just one person.

[oregon_phil]

B) No. Have you read the SMA inverter manual or searched the web regarding SPS functionality?

SMA inverters using the SPS outlet require GFCI outlets. One hint of abnormal loads or loads too high, the SPS outlet will shutdown. I have one and it is picky.

Combining SPS outlets from multiple inverter will not work. It will violate warranties. It won't work. Time to move on.

[SoftwareDude]

A) works for grid-tied inverters because they sync to an independent grid voltage waveform. B) does not work because they don't sync to anything.

Is there something you can buy to sync them so that you can essentially combine them into a 240v plug and plug it into a transfer switch?

[SoftwareDude]

A) works for grid-tied inverters because they sync to an independent grid voltage waveform. B) does not work because they don't sync to anything.

Ah... That makes sense. Thanks for that.

[solardreamer]

I have seen that video. Anything is possible on Youtube. It is an interesting science experiment and I am surprised it has only received 100 views considering how many schemes go viral on Youtube. It is not sustainable because the H6 is a dead end inverter with no support. That video does nothing to address the complexities of powering an electrical device with solar. I have reach that conclusion after many hours of watching Youtube videos.

H6 definitely is dead end and no support. There is also E5 that has support but not available in the US yet.

[solardreamer]

Thanks for the responses everyone. Here is something that is a little bit confusing to me.

What is the difference between:
A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load.
B) 5x 240v AC output SPS' wired into a combiner box then out to the load.

I can't find a good reason why A would work but B would not work. Thoughts?

A) works for grid-tied inverters because they sync to an independent grid voltage waveform. B) does not work because they don't sync to anything.

[Mike90250]

Thanks for the responses everyone. Here is something that is a little bit confusing to me.

What is the difference between:
A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load.
B) 5x 240v AC output SPS' wired into a combiner box then out to the load.

I can't find a good reason why A would work but B would not work. Thoughts?

> A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load.
Will only work with 240V loads, those inverters use a neutral wire for reference, not for load balance ( from what little I know about microinverters)


> B) 5x 240v AC output SPS' wired into a combiner box then out to the load.
SPS' don't have a Sync signal, so you will have: (in order of likelihood)
a) smoke
b) 5 random phases
c) might get super lucky and some would sync together somehow

[SoftwareDude]

The key phrase from SMA is "secure power supply will not work with SunSpec Rapid Shutdown devices". SMA now only promotes SunSpec Rapid Shutdown devices on their website. I have verified TS4-R-O modules do work with SPS, but they have been obsoleted by Tigo. The newer TS4-A modules are rumored not to work with SPS. There was a guy on this forum a couple years ago that used TS4-F rapid shutdown modules with SPS successfully that required a work around to power the RSS transmitter when the power was down.

It seems like a lot of work for TIGO to keep validating whether or not their modules work with SMA SPS functionality so I would expect TIGO to stop this work for new inverters.



SoftwareDude, can you explain your reasoning behind your last statement? Choices aren't always If A then B. Why do you think scenario A would work?

Sure. It really just comes back to my original question about running multiple SPS power supplies in parallel.

Let's say that I have 5 inverters that have Secure Power Supplies (SPS) on each one of them. Let's say that all 5 of these SPS' are all split phase 240v. The SPS' will not be active (hot) until the grid goes down due to inverter shutting off power to grid and routing power to the SPS. So when the grid goes down, all 5 of the SPS' will go hot and start pushing 240v. At that same time that the grid goes down, and the inverters route power to their respective SPS, what is preventing me from running all 5 SPS' into a combiner box (in parallel) and outputting 240v to let's say a transfer switch?

Thanks again.

[oregon_phil]

SunnyBoy seems to be discontinuing support for their SPS technology. They no longer sell optimizers or RSM that work with it. Rumor has it that Tigo RSM still work, but have not tried it personally. Which means if you really 100% want that feature you better build a pergola and therefore not need to use optimizers or RSM because that is the only sure fire way it will work.

The key phrase from SMA is "secure power supply will not work with SunSpec Rapid Shutdown devices". SMA now only promotes SunSpec Rapid Shutdown devices on their website. I have verified TS4-R-O modules do work with SPS, but they have been obsoleted by Tigo. The newer TS4-A modules are rumored not to work with SPS. There was a guy on this forum a couple years ago that used TS4-F rapid shutdown modules with SPS successfully that required a work around to power the RSS transmitter when the power was down.

It seems like a lot of work for TIGO to keep validating whether or not their modules work with SMA SPS functionality so I would expect TIGO to stop this work for new inverters.

Thanks for the responses everyone. Here is something that is a little bit confusing to me.

What is the difference between:
A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load.
B) 5x 240v AC output SPS' wired into a combiner box then out to the load.

I can't find a good reason why A would work but B would not work. Thoughts?

SoftwareDude, can you explain your reasoning behind your last statement? Choices aren't always If A then B. Why do you think scenario A would work?

[SoftwareDude]

Thanks for the responses everyone. Here is something that is a little bit confusing to me.

What is the difference between:
A) 5x split phase 240v AC output inverters wired into a combiner box then out to the load.
B) 5x 240v AC output SPS' wired into a combiner box then out to the load.

I can't find a good reason why A would work but B would not work. Thoughts?

[khanh dam]

SunnyBoy seems to be discontinuing support for their SPS technology. They no longer sell optimizers or RSM that work with it. Rumor has it that Tigo RSM still work, but have not tried it personally. Which means if you really 100% want that feature you better build a pergola and therefore not need to use optimizers or RSM because that is the only sure fire way it will work.