Sunny Boy Grid Tied Inverter in Island Mode 60hz

[MurphyGuy]

I noticed that my grid tied Sunny Boy SB6.0 inverter puts out a balanced current.. current is equal on both 120 volt legs.

Does this remain the same if the normally grid tied inverter is put into Island Mode 60hz and used off-grid with frequency shift power control?

Anyone know?

 

[drewjet]

I don't think a SunnyBoy will go into Island mode, I think you need a Sunny Island to do that.

As for being balanced, It is going to put out the max that it can, and will balance between the legs, because all it wants to do is feed the Grid as much as it can.

 

[MurphyGuy]

I don't think a SunnyBoy will go into Island mode, I think you need a Sunny Island to do that.

As for being balanced, It is going to put out the max that it can, and will balance between the legs, because all it wants to do is feed the Grid as much as it can.

SunnyBoy inverters most certainly can be used in Island Mode off-grid.. I do it every time a storm knocks out power.

There's a setting inside the inverter called "Island Mode".

When in Island Mode, the inverter's output can be "throttled" by the Sunny Islands using a technique called Frequency Shift Power Control. If the sun is shining and the inverter wants to put out full power, the Sunny Islands can raise the frequency slightly which causes the output from the Sunny Boy's to decrease proportionally to the frequency increase.

When grid tied, the legs are balanced because the grid is basically infinite.. But in off-grid mode, it would be rare that the two 120v legs in my home are drawing the exact same power, so there's an imbalance..
What I want to know is who manages that imbalance... is it done in the Sunny Islands or do the Sunny Boy's do it?

 

[BobK53]

SunnyBoy inverters most certainly can be used in Island Mode off-grid.. I do it every time a storm knocks out power.

There's a setting inside the inverter called "Island Mode".

When in Island Mode, the inverter's output can be "throttled" by the Sunny Islands using a technique called Frequency Shift Power Control. If the sun is shining and the inverter wants to put out full power, the Sunny Islands can raise the frequency slightly which causes the output from the Sunny Boy's to decrease proportionally to the frequency increase.

When grid tied, the legs are balanced because the grid is basically infinite.. But in off-grid mode, it would be rare that the two 120v legs in my home are drawing the exact same power, so there's an imbalance..
What I want to know is who manages that imbalance... is it done in the Sunny Islands or do the Sunny Boy's do it?

I currently have a professional installer solar panel system with 24 solar modules and two SMA Sunny Boy 3000 inverters. On my own (DIY) I’m adding 24 additional solar modules, two SB6.0 grid-tied PV inverters, two Sunny Island 4548 off-grid inverters and two 48V battery packs.
The plan is to use the SI inverters to form a stand alone system, and Frequency Shift Power Control to shut down power generation by the SB inverters when the power is both more than I need at any time and if the batteries are fully charged. I’ve got most of the components that I need, and am trying to determine how to wire it all together. The AC output from each of the SB6.0 inverters will go to two 30A breakers in a new (off-grid) breaker box. The AC input on the SI4548 will come from the breaker box, fed through 50A breakers. One for each SI4548 inverter. DC circuit breakers will be used between each SI4548 inverter and the LiFePO4 48V battery bank. The SI4548 inverters will supply the DC current to charge the battery bank, but each battery pack has an internal BMS.
Do I need:
1) DC circuit breakers between the solar modules and the SB6.0 inverters,
2) What else do I need?
None of this addition is currently connected to the house grid-tied system. When the new off-grid system is working the grid tie will be disconnected.
BobK53

 

[MurphyGuy]

I currently have a professional installer solar panel system with 24 solar modules and two SMA Sunny Boy 3000 inverters. On my own (DIY) I’m adding 24 additional solar modules, two SB6.0 grid-tied PV inverters, two Sunny Island 4548 off-grid inverters and two 48V battery packs.
The plan is to use the SI inverters to form a stand alone system, and Frequency Shift Power Control to shut down power generation by the SB inverters when the power is both more than I need at any time and if the batteries are fully charged. I’ve got most of the components that I need, and am trying to determine how to wire it all together. The AC output from each of the SB6.0 inverters will go to two 30A breakers in a new (off-grid) breaker box. The AC input on the SI4548 will come from the breaker box, fed through 50A breakers. One for each SI4548 inverter. DC circuit breakers will be used between each SI4548 inverter and the LiFePO4 48V battery bank. The SI4548 inverters will supply the DC current to charge the battery bank, but each battery pack has an internal BMS.
Do I need:
1) DC circuit breakers between the solar modules and the SB6.0 inverters,
2) What else do I need?
None of this addition is currently connected to the house grid-tied system. When the new off-grid system is working the grid tie will be disconnected.
BobK53

You should be using a SINGLE battery bank connected to both Sunny Islands.. DO NOT use one bank for each.. they need to feed off the same 48v source.. In fact, from my understanding, even the DC Cables should be approximately the same length.

I do not have any breakers on my DC solar lines.. my Sunnyboy has a disconnect built right into it.

Your Sunny Islands will not be able to handle more than 12kW of input.. and that's assuming you have a very large battery bank north of 30 or 40kW.
Hmm.. I forget the formula, but I think your battery needs to be twice the size of the solar array.. So if you have a 10kW battery, you shouldn't hook it to more than 5kW of solar power. You should double check my statement but its something like that.

I can tell you that my battery is 25 kWh's of lithium and my array is 11kW.. and when I turn on both of my Sunny Boy SB6.0, which are both capable of frequency shifting, the system gets a bit unstable when the batteries are near full and the sun is shining bright and the house isn't drawing much juice.. It works, but I can tell from the frequency shifting its not happy...

I will generally turn off one of the Sunny Boy's when we go into off grid mode, and unless I need that extra juice due to a cloudy day or something, I leave it off and run on just the one.

My system consists of nothing more than a standard grid-tied solar array, and the completely separate off-grid system that back feeds a mechanically interlocked generator breaker.. I even hook a 4ga 4 wire SO Cord with 50 amp plugs when I connect it.

 

[BobK53]

SunnyBoy inverters most certainly can be used in Island Mode off-grid.. I do it every time a storm knocks out power.

There's a setting inside the inverter called "Island Mode".

When in Island Mode, the inverter's output can be "throttled" by the Sunny Islands using a technique called Frequency Shift Power Control. If the sun is shining and the inverter wants to put out full power, the Sunny Islands can raise the frequency slightly which causes the output from the Sunny Boy's to decrease proportionally to the frequency increase.

When grid tied, the legs are balanced because the grid is basically infinite.. But in off-grid mode, it would be rare that the two 120v legs in my home are drawing the exact same power, so there's an imbalance..
What I want to know is who manages that imbalance... is it done in the Sunny Islands or do the Sunny Boy's do it?

The Sunny Boy inverters on my system

You should be using a SINGLE battery bank connected to both Sunny Islands.. DO NOT use one bank for each.. they need to feed off the same 48v source.. In fact, from my understanding, even the DC Cables should be approximately the same length.

I do not have any breakers on my DC solar lines.. my Sunnyboy has a disconnect built right into it.

Your Sunny Islands will not be able to handle more than 12kW of input.. and that's assuming you have a very large battery bank north of 30 or 40kW.
Hmm.. I forget the formula, but I think your battery needs to be twice the size of the solar array.. So if you have a 10kW battery, you shouldn't hook it to more than 5kW of solar power. You should double check my statement but its something like that.

I can tell you that my battery is 25 kWh's of lithium and my array is 11kW.. and when I turn on both of my Sunny Boy SB6.0, which are both capable of frequency shifting, the system gets a bit unstable when the batteries are near full and the sun is shining bright and the house isn't drawing much juice.. It works, but I can tell from the frequency shifting its not happy...

I will generally turn off one of the Sunny Boy's when we go into off grid mode, and unless I need that extra juice due to a cloudy day or something, I leave it off and run on just the one.

My system consists of nothing more than a standard grid-tied solar array, and the completely separate off-grid system that back feeds a mechanically interlocked generator breaker.. I even hook a 4ga 4 wire SO Cord with 50 amp plugs when I connect it.

Hello MurphyGuy, thanks for the reply.
Item 1: I do have two “battery banks” with each containing 16S 26P LiFePO4 cell modules. The two “battery banks” are connected in parallel, so the two SI4548 inverters can be connected in a variety of ways. The installer who helped design and set up the system recommended that each SI4548 inverter be connected through a 125A DC circuit breaker to one battery bank. With the two battery banks connected parallel they are components of a single battery bank. If one of the SI4548 inverters is down for any reason both battery banks will be charged at 1/2 amperage (~45A). To prolong battery health the battery builder (Discover Energy) recommends that the battery banks not be charged at greater than 92A, so I’ve decided to charge at a max of 90A.
Item 2: You stated that your Sunny Boy PV inverters can be set to “Island Mode.” I cannot find anything in the Installation Guide that came with the SB Inverters or anything else that I’ve been able to get from SMA. Wording in the Installation Guide indicates that without the grid connected only 2,000W of power can be used through the Secure Power Supply Operation, after I flip the switch. That is only 1/3 of the total power output of the SB 6.0 inverters.
My plan was to use the two SI4548 inverters to creat a grid-like current to enable full power of the SB inverters. This setup was recommended by a salesman at the Renvu where I bought inverters.
At what point in commissioning the SB inverters are you able to set the inverters to Island Mode. Your reply would be very much appreciated.
BobK53
Louisiana

 

[Hedges]

Although Sunny Boy has a neutral wire, it doesn't use it for anything other than looking at voltage. That may be required for compliance now, but earlier models used neutral just to auto-detect 208V, 240V, 277V. Without neutral connected, other jumper positions dictate what voltage it is to use. There was a paper from SMA suggesting an AHJ ought to accept neutral wire same gauge as ground wire, and smaller than L1/L2.

BobK -

For the model I think you have, "Compatible if country data set CA Rule 21 is set"
Early models had to be manually set to backup or island, later came with backup enabled (responded to RS-485).
Yours, it may have locked into "UL-1741" after 10 hours of operation. A grid-guard code issued by SMA is needed to change the setting. A password may be required - perhaps written inside cover of inverter by installer. A personal unlocking key (PUK) from SMA will let you get in.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-22.pdf

"UL1741/2016/120 L-N-L is factory-set."

"• UL1741/2016/120 L-N-L • HECO_OHM Rule 14H SDR 1.1/120 L-N-L • CA Rule 21 / 120 L-N-L • NE-ISO / 120 L-N-L"

https://files.sma.de/downloads/SBxx-1SP-US-41-IA-xx_12.pdf

I've never used your model:

"Procedure: 1. Open the user interface (see Section 4.2, page 24). 2. Log into the user interface (see Section 4.3, page 28). 3. Call up the menu Device Parameters. 4. Click on [Edit parameters]. 5. Log in using the SMA Grid Guard code to change those parameters designated by a lock (only for installers): • Select the menu User Settings (see Section 4.4, page 30). • In the subsequent context menu, select [SMA Grid Guard login]. • Enter the SMA Grid Guard code and select [Login]. 6. Expand the parameter group that contains the parameter which is to be configured. 7. Change the desired parameters. 8. Select [Save all] to save the changes. ☑ The inverter parameters are set."

https://files.sma.de/downloads/SBxx-US-1XP-41-BA-en-11.pdf

 

[robby]

Until @MurphyGuy gets back I can tell you that when I was researching this kind of application some of the options are hidden in an Installer Menu that requires a password. The password was not hard to figure out, it was something about adding up some numbers if I remember correctly.

Update:
Just looked at my Notes and its the last menu called "User Level" There are three options with Installer being one of them. The Password is found by adding the individual numbers in the Runtime Hours that is on the display. So if your Runtime is 30523 hours the password word is 13.
I would not mess with that menu until you get some advice on how to proceed further.

 

[Hedges]

I can tell you that my battery is 25 kWh's of lithium and my array is 11kW.. and when I turn on both of my Sunny Boy SB6.0, which are both capable of frequency shifting, the system gets a bit unstable when the batteries are near full and the sun is shining bright and the house isn't drawing much juice.. It works, but I can tell from the frequency shifting its not happy...

I will generally turn off one of the Sunny Boy's when we go into off grid mode, and unless I need that extra juice due to a cloudy day or something, I leave it off and run on just the one.

I would try staggering the frequency range of the two Sunny Boys, so one gets curtailed and the last few hundred watts or 1 kW are from a single inverter. That should automatically do what you've done manually.

 

[Hedges]

Until @MurphyGuy gets back I can tell you that when I was researching this kind of application some of the options are hidden in an Installer Menu that requires a password. The password was not hard to figure out, it was something about adding up some numbers if I remember correctly.

That was probably based on sum of day, month, year. That worked with Sunny Boy Control. Maybe also Sunny Web Box. (both RS-485 in my case.)
Different now (and I suspect is implemented in my host PC or in the Speedwire card), although I think I had the previous password it wasn't accepted. Appeared newer version of Sunny Explorer required a different password complexity. I needed PUK Personal Unlocking Key to get in. and Installer Password to change key parameters. Manual for SB 6.0 says not to use Sunny Explorer, apparently WLAN which I take to mean WiFi, and a browser.

 

[robby]

That was probably based on sum of day, month, year. That worked with Sunny Boy Control. Maybe also Sunny Web Box. (both RS-485 in my case.)
Different now (and I suspect is implemented in my host PC or in the Speedwire card), although I think I had the previous password it wasn't accepted. Appeared newer version of Sunny Explorer required a different password complexity. I needed PUK Personal Unlocking Key to get in. and Installer Password to change key parameters. Manual for SB 6.0 says not to use Sunny Explorer, apparently WLAN which I take to mean WiFi, and a browser.

Our posts keep colliding
If it has changed again I would not be surprised. I love SMA products but they don't make life easy when it comes to programming the unit.

 

[Hedges]

Here's the link to request PUK, if you don't have password for your inverters and can't get it from installer

https://files.sma.de/downloads/PUK-ANTRAG-en-24.pdf

For Grid-Guard code:

https://www.sma.de/fileadmin/content/landingpages/pl/FAQ/GRIDGUARD-ZEN151321.pdf

 

[Hedges]

I do have two “battery banks” with each containing 16S 26P LiFePO4 cell modules. ... To prolong battery health the battery builder (Discover Energy) recommends that the battery banks not be charged at greater than 92A, so I’ve decided to charge at a max of 90A.

Check out the charge rate vs. temperature specs for some cells in post below.
If max recommended charge current is 92A, that is probably around 25 degrees C. Most cells are spec'd for about 0.5C charge rate. your "16s 26P LiFePO4" I have no idea what capacity that is. Do you really have 26 cells in parallel? Actually, 26 sets of 16s (series), and those 26 sets in parallel?

Most off-grid users I think could charge at 0.15C rather than 0.5C and still recharge fully under most weather conditions.
I suggest considering what temperature range your cells could see, and set charge rate for what is OK at that temperature. Then set BMS to disable charging below that temperature.

Why you cannot charge LiFePO4 below 0 degrees Celsius

...I glazed over...Soooo far past me...... but, does this mean that the claims of the -20F chargeable LiFePO4 cells could be true? Based on what i’ve read in this forum, not for any practical use. I’m no expert on the matter, though.

diysolarforum.com

 

[SolarPrep]

Hedges and MurphyGuy: If you were buying today, at the going rates for new equipment, would you go with SMA again, knowing what you know now? The only other real contenders that are readily available and are properly listed would be Radian, XW-Pro, and Sol-Ark. Some people might throw Magnum into that mix, but I don't consider it to be at the same level as the others. And EVO is not available in 48v at the level of the other units.

 

[SolarPrep]

I guess I should add that there are still some SMA inverters for sale through EBAY and Craigslist from the DC Solar fiasco, which you are both well aware of. That puts Sunny Island at a better price than XW Pro, but not by much. Warranty can be an issue too.

 

[RCinFLA]

I noticed that my grid tied Sunny Boy SB6.0 inverter puts out a balanced current.. current is equal on both 120 volt legs.

Does this remain the same if the normally grid tied inverter is put into Island Mode 60hz and used off-grid with frequency shift power control?

Anyone know?

The Sunny Island output transformer provides the 120/120vac leg balance for the Sunny Boy,

It's just like putting an autotransformer on a 240vac only inverter.

 

[BobK53]

Although Sunny Boy has a neutral wire, it doesn't use it for anything other than looking at voltage. That may be required for compliance now, but earlier models used neutral just to auto-detect 208V, 240V, 277V. Without neutral connected, other jumper positions dictate what voltage it is to use. There was a paper from SMA suggesting an AHJ ought to accept neutral wire same gauge as ground wire, and smaller than L1/L2.

BobK -

For the model I think you have, "Compatible if country data set CA Rule 21 is set"
Early models had to be manually set to backup or island, later came with backup enabled (responded to RS-485).
Yours, it may have locked into "UL-1741" after 10 hours of operation. A grid-guard code issued by SMA is needed to change the setting. A password may be required - perhaps written inside cover of inverter by installer. A personal unlocking key (PUK) from SMA will let you get in.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-22.pdf

"UL1741/2016/120 L-N-L is factory-set."

"• UL1741/2016/120 L-N-L • HECO_OHM Rule 14H SDR 1.1/120 L-N-L • CA Rule 21 / 120 L-N-L • NE-ISO / 120 L-N-L"

https://files.sma.de/downloads/SBxx-1SP-US-41-IA-xx_12.pdf

I've never used your model:

"Procedure: 1. Open the user interface (see Section 4.2, page 24). 2. Log into the user interface (see Section 4.3, page 28). 3. Call up the menu Device Parameters. 4. Click on [Edit parameters]. 5. Log in using the SMA Grid Guard code to change those parameters designated by a lock (only for installers): • Select the menu User Settings (see Section 4.4, page 30). • In the subsequent context menu, select [SMA Grid Guard login]. • Enter the SMA Grid Guard code and select [Login]. 6. Expand the parameter group that contains the parameter which is to be configured. 7. Change the desired parameters. 8. Select [Save all] to save the changes. ☑ The inverter parameters are set."

https://files.sma.de/downloads/SBxx-US-1XP-41-BA-en-11.pdf

Hedges,
The inverters that I am using are:
SMA SB6.0 1SP-US-40 (09/2018)
SMA SI4548-US-10 (04/2018)
An annoying thing that I have noticed

Although Sunny Boy has a neutral wire, it doesn't use it for anything other than looking at voltage. That may be required for compliance now, but earlier models used neutral just to auto-detect 208V, 240V, 277V. Without neutral connected, other jumper positions dictate what voltage it is to use. There was a paper from SMA suggesting an AHJ ought to accept neutral wire same gauge as ground wire, and smaller than L1/L2.

BobK -

For the model I think you have, "Compatible if country data set CA Rule 21 is set"
Early models had to be manually set to backup or island, later came with backup enabled (responded to RS-485).
Yours, it may have locked into "UL-1741" after 10 hours of operation. A grid-guard code issued by SMA is needed to change the setting. A password may be required - perhaps written inside cover of inverter by installer. A personal unlocking key (PUK) from SMA will let you get in.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-22.pdf

"UL1741/2016/120 L-N-L is factory-set."

"• UL1741/2016/120 L-N-L • HECO_OHM Rule 14H SDR 1.1/120 L-N-L • CA Rule 21 / 120 L-N-L • NE-ISO / 120 L-N-L"

https://files.sma.de/downloads/SBxx-1SP-US-41-IA-xx_12.pdf

I've never used your model:

"Procedure: 1. Open the user interface (see Section 4.2, page 24). 2. Log into the user interface (see Section 4.3, page 28). 3. Call up the menu Device Parameters. 4. Click on [Edit parameters]. 5. Log in using the SMA Grid Guard code to change those parameters designated by a lock (only for installers): • Select the menu User Settings (see Section 4.4, page 30). • In the subsequent context menu, select [SMA Grid Guard login]. • Enter the SMA Grid Guard code and select [Login]. 6. Expand the parameter group that contains the parameter which is to be configured. 7. Change the desired parameters. 8. Select [Save all] to save the changes. ☑ The inverter parameters are set."

https://files.sma.de/downloads/SBxx-US-1XP-41-BA-en-11.pdf

Hedges,
The inverters that I am using are:
SMA SB6.0 1SP-US-40 (09/2018)
SMA SI4548-US-10 (04/2018)
Something that I noticed about SMA is that they apparently do not see any need to update their Operating Manuals when inverter capabilities have changed. When talking about communications between a SI4548 and a SB6.0 the manual shows the use of an RS485 cable. They even include photos of the connection screws on the SB inverter. My SB6.0 inverters do not have any connection that looks like what they show in the manual. After speaking with several SMA personnel one guy finally said that the SB6.0 has communication built in. No RS485 piggy-back module is needed. They also refer to a piece of equipment called the Sunny WebBox that was discontinued in about 2015. Both my SB6.0 and SI4548 were made in 2018. Why do they reference an item discontinued in 2015 in a manual for inverters that were made in 2018? The Operating Manual was printed in 2015. Apparently SMA did not see any reason to update operating manuals that were shipped with newer inverters.
Anyway, I thank everyone who has responded to my post. After I download some more booklets and obtain the PUK I will probably have more questions.

(When I was attempting to commission one of the SB6.0 inverters I forgot to write the password anywhere for future reference. I currently cannot even get back into the inverter that I myself commissioned.)
BobK53

 

[Hedges]

The Sunny Island output transformer provides the 120/120vac leg balance for the Sunny Boy,

It's just like putting an autotransformer on a 240vac only inverter.

Yes, within the limits of Sunny Island battery charger and inverter. There are no magnetics providing 120/240V conversion like an auto-transformer. It doesn't matter that Sunny Island is transformer type vs. high frequency. Power from Sunny Boy feeds loads on both phases. Let's say one phase has 2kW and the other has 4kW. Sunny Boy delivers 6kW at 240V, one Sunny Island sucks down 1kW to battery and the other inverts 1 kW from battery to the other phase.

Sunny Island can work with Sunny Boy 2x its wattage, e.g. 4x 6kW Sunny Boy with 2x Sunny Island. That could take in 24kW PV for 24kW loads, or 12kW loads and 12kW battery charging. There is a limit to how much imbalance could be supported. Similar if grid-tied, with only one phase connected to grid and two (or 3 for 3-phase) Sunny Island. I haven't tried that, but I think it could handle a limited amount of GT PV distributed across all phases. Unlike off-grid, it can't use frequency shift to curtail production.

Something I'm not sure about is how well an auto-transformer will balance power between two 120V inverters like Sunny Island.
The windings of a transformer have resistance, and IR drop results in lower voltage when delivering power (higher voltage when taking in power.) Typically 5% or so above nominal voltage at no-load, 5% below at maximum current. An auto-transformer could have second half of windings with extra turns if expected to always deliver power, might be same number of windings if meant to balance between phases. If output of Sunny Island is "stiff", doesn't sag in voltage at higher current, it couldn't draw any current from transformer. If Sunny Island was programmed to deliver a voltage which sagged at higher current, then balancing transformer should work. If feedback point was taken after switching circuit and before H-bridge, IR drop through H-bridge could provide that, some voltage drop determined by resistance.

Load fed by a 240V to 120/240V split-phase transformer would always present a balanced load on 240V input side (because no neutral for imbalanced current.)

 

[Hedges]

Hedges,
The inverters that I am using are:
SMA SB6.0 1SP-US-40 (09/2018)
SMA SI4548-US-10 (04/2018)
An annoying thing that I have noticed

Something that I noticed about SMA is that they apparently do not see any need to update their Operating Manuals when inverter capabilities have changed. When talking about communications between a SI4548 and a SB6.0 the manual shows the use of an RS485 cable. They even include photos of the connection screws on the SB inverter. My SB6.0 inverters do not have any connection that looks like what they show in the manual. After speaking with several SMA personnel one guy finally said that the SB6.0 has communication built in. No RS485 piggy-back module is needed. They also refer to a piece of equipment called the Sunny WebBox that was discontinued in about 2015. Both my SB6.0 and SI4548 were made in 2018. Why do they reference an item discontinued in 2015 in a manual for inverters that were made in 2018? The Operating Manual was printed in 2015. Apparently SMA did not see any reason to update operating manuals that were shipped with newer inverters.
Anyway, I thank everyone who has responded to my post. After I download some more booklets and obtain the PUK I will probably have more questions.

(When I was attempting to commission one of the SB6.0 inverters I forgot to write the password anywhere for future reference. I currently cannot even get back into the inverter that I myself commissioned.)
BobK53

Note that your Sunny Boy model is listed under the heading "PV Inverters for Planned Systems (as of April 2019)" but is of an earlier date.
There was some change between -40 model and -41. I don't know if that is hardware or only firmware. I think a later version of firmware is required for battery backup system "✓ 1 Compatible if country data set CA Rule 21 is set" but not for off-grid.

https://files.sma.de/downloads/SB-OffGrid-TI-US-en-22.pdf

These newer models never had RS-485. Possibly there is a daughter card for them with that interface, probably not. There is a daughter card for Sunny Island with SpeedWire, but I don't think its firmware supports using that to talk with Sunny Boy. Instead (only SMA Data Manager), it appears to be the frequency-watts option of Rule 21 that enables frequency-shift. I think UL-1741 is required for new GT PV inverters in California and some other locations, but I thought frequency-watts is only to be used if utility approves. But I haven't seen instructions for enabling frequency-watts separately from Rule 21.

Just Rule 21 frequency-watts should make grid-backup and off-grid work. That requires recent firmware. For off-grid, setting "default = offgrid" or "country set = offgrid60", whichever yours has, should work with original firmware.

I got an old new-in-box Sunny WebBox. now there is Data Manager or something like that which I think uses SpeedWire to adjust Sunny Boy output for purposes such as remote control of PV plants (for a more stable grid.) I don't think it is needed for stand-alone use.

I think you can probably connect by either WiFi or Ethernet. I have SpeedWire (Ethernet) cards for some models, but for that I use Sunny Explorer, which SMA does not recommend for setting parameters (only reading) for your model. See if WiFi and browser works.

https://files.sma.de/downloads/EDMM-10-DS-en-35.pdf

 

[Hedges]

Hedges and MurphyGuy: If you were buying today, at the going rates for new equipment, would you go with SMA again, knowing what you know now? The only other real contenders that are readily available and are properly listed would be Radian, XW-Pro, and Sol-Ark. Some people might throw Magnum into that mix, but I don't consider it to be at the same level as the others. And EVO is not available in 48v at the level of the other units.

I guess I should add that there are still some SMA inverters for sale through EBAY and Craigslist from the DC Solar fiasco, which you are both well aware of. That puts Sunny Island at a better price than XW Pro, but not by much. Warranty can be an issue too.

Sunny Island and Sunny Boy are great solid products. Price no object I'd use them for my grid backup application. I would like an export-limit function to have 20kW PV on a 10kW connection agreement; that may be possible with Data Manager and newer SB or Gateway and older SB.

Another good feature for people who use lithium batteries could be shifting time of grid use/backfeed. I don't think that is in current Sunny Island firmware. Likely in the new 8.0 model (no US version yet), but not sure.

There may be lesser models at much lower price points which have desired features. It was because I paid $0.25/W for Sunny Island (Thanks Warren Buffet and DC Solar!) and $0.10/W for old model Sunny Boy, all new in the box, that I could splurge. I think SMA honors the warranty to a certain period after date of manufacture.

I think I've figured out how to massively exceed export limit in PV without exporting too much: 10kW of GT PV feeding main breaker panel. Sunny Island configured to draw from main panel but not export, with up to 38kW of GT PV. Whenever production on island side exceeds consumption, Sunny Island would disconnect from grid and raise frequency (same as if fed by generator). In extended grid-down situation, flip interlocked breakers so Sunny Island feeds main panel instead of other way around. 24kW of Sunny Island can manage 48kW of GT PV.