Sunny Boy and Sunny Island

[Shinebox]

Interesting. I will check that out.

 

[Shinebox]

You definitely have something exceptional going on there. My country settings are all locked and require grid guard.

 

[Consumerbot3418]

You definitely have something exceptional going on there. My country settings are all locked and require grid guard.

Hmm… wonder if it’s because I was off-grid from the get-go? Perhaps the timer only counts time on the grid-tie options?

Guess I’ll just count myself lucky, and leave everything the way it is!

 

[Solarisium]

You'll need to change it from the standard to "Island Mode".

Thanks!

Finally term “island” is decoded to

Sure. Yes, connect to the inverter via https://your-inverters-ip (wifi or ethernet), and sign in as the installer, as you said. Visit "Device Parameters", click "Edit Parameters". Under "Grid Monitoring", find "Set country standard" dropdown. Choose "SMA Island mode 60 Hz", click "Save All" button on top. Maybe it's because I didn't go through the installation assistant, or maybe it's normal? But I've got 100+ days of operating time, 5+MWh of production, and that option is still there. I actually just changed it, just to confirm that I could, and it did "take", no Grid Guard Code required.

That’s interesting!
I want to guess because you configured your Sunny Boy as Off grid from the beginning!?

My SB 3.8 US-41 was configured to sync with grid at 120V and it actually worked and generated 120V until I connected it to 240V while still within the initial 10 hours. Per @Hedges this was an undocumented feature!

So it is not surprising that yours can do magic things too!

I just checked my Sunny Boy via WiFi , and yes, it does require grid guard code to make changes:


I needed to change the country standard and set it to California rule 21. Had to request the grid code from SMA. I t them a screenshot of the email my utility sent me referencing Rule21 requirements. They provided me with the code.

 

[Hedges]

I was excited to learn that -41 can connect to 120V single phase.
I think the last 120V Sunny Boy was 700W or maybe 1800W, none offered anymore.

If someone has just one Sunny Island, they've needed a transformer to produce the 120/240V required by SB.

Earlier 5000US series had jumpers to specify grid voltage, and one for Automatic Grid Voltage Detection:

"The Sunny Boy’s software is designed to automatically detect which grid voltage it is feeding. Depending upon the voltage and phase angle between L1-N and L2-N, the inverter will determine if it is connected to a 208 V, 240 V or 277 V grid."

https://documents.unboundsolar.com/legacy/pdfs/inverter%20pdf%20folder/SB5000US-8000US-11-manual.pdf

The 277V configuration (one leg of 277/480Y) has L1 and N both connected to neutral.
SB -41 doesn't support 277, and that connection has now been reported to set it for 120V. (Undocumented feature!) Presumably max wattage limited to about the current inverter would have delivered into 208V.

I think SB connected to a small breaker panel having interlock could be switched between 120/240V grid and 120V Sunny Island. I expect it to auto-recognize grid voltage even after 10 hours operation when country standard has been locked.

 

[kts78]

I just set up the same, SB6.0 and 2 SI6048's all off grid. Used grid gaurd code to set SB to island and all worked fine for 3 days-- ran well for newly planted grass, charged the battery back and when the batteries were reaching 100% solar started ramping down to eventually sitting at 9w (62hz from SI), the problem is that was 3 days ago and the sunny island is still holding at 62hz and the SB just says "active power limit ac frequency" batteries are down to 80%, I can turn pump on and solar never comes back on. Is there a setting in the SI that needs to be set? or is this something that needs changed in the SB? I have done all the setup using manuals and started looking online for some more clarification. Any help from guys who know this stuff would be great!! Thanks

 

[Hedges]

One thing I've heard is that SI may do a poor job of estimating SoC (although it is said to be good at maintaining lead-acid.)

I assume you're using lithium. What battery or BMS, and is there communication?

Current Connected has SOK batteries working closed-loop with SI, think he said some issue with bottom 20% of SoC.
Other members use REC, closed loop.
Some members use open loop.

How do you know battery SoC, is that BMS?
Are you using SI open-loop, with VRLA settings?
If so, could be battery voltage isn't down to SI's "float" setting yet.
I think 48V nominal VRLA settings can't match LiFePO4 voltages. A different nominal does, it may be 46V nominal VRLA.

 

[kts78]

One thing I've heard is that SI may do a poor job of estimating SoC (although it is said to be good at maintaining lead-acid.)

I assume you're using lithium. What battery or BMS, and is there communication?

Current Connected has SOK batteries working closed-loop with SI, think he said some issue with bottom 20% of SoC.
Other members use REC, closed loop.
Some members use open loop.

How do you know battery SoC, is that BMS?
Are you using SI open-loop, with VRLA settings?
If so, could be battery voltage isn't down to SI's "float" setting yet.
I think 48V nominal VRLA settings can't match LiFePO4 voltages. A different nominal does, it may be 46V nominal VRLA.

Thanks for the response
Trophy lith battery- no comunication, they (trophy) told me not to, said their bms would take care of it.
using VRLA
yea I wondered about the voltage- currently at 53.13v
I'm not sure on the open loop vs closed loop

 

[Hedges]

No communication means open loop.

All BMS can take care of open-loop is disconnect for high or low voltage, and rebalance if voltage is in a certain range.

With closed loop, BMS would tell SI what voltage (and maybe current) to deliver. That would take care of it, including slowing down charge near the top if needed to rebalance without having a runner that reaches high voltage disconnect.

Since you are running open loop,
Check SI mode on its display (probably "Float")
Check what float voltage is set "ChrgVtgFlo" default 2.25 V
Check what nominal voltage (probably 48V)

48V nominal is 24, 2V cells. 2.25V x 24 = 54V, "currently at 53.13v" it might aim for 54V.

16 cells LiFePO4, 54V / 16 cells = 3.375V/cell

I think you need to determine what low voltage disconnect, Full charge voltage, and float voltage you want for the LiFePO4 pack.
Then consider the allowed range of VRLA cell parameters. I don't believe 24 cells will let all three be the voltage you want. Some other number, 23, 22, or was it 25? VRLA cells with some fudged values should match what your pack wants.

 

[kts78]

ok, I think that might be it. I had to set the charge voltage because it would trip the BMS with an over voltage error, but I didn't look at the float. They wanted 56.8 max on the charge, 53-54.5 for float. I ran out of time and didn't find where to set the float. Thanks a lot for the help.

 

[kts78]

Just wanted to follow up. I left it go another day and the panels kicked in 52.5V. Changed the float voltage to 2.27v and the problem seems to be resolved- batteries now at 99%-100% SOC and panels come on if I turn on any load. Thanks Hedges for your help!

 

[Hedges]

Good that works, but only 1% higher made the difference. I'd be concerned that temperature differences, or one cell being a slight runner, and the problem could return.

Now if float is too high, I think actual SoC continues to climb. I think things would work better if Ah drawn was also used to enable a boost charge. Maybe closed-loop with BMS does that, but you're stuck with faking VRLA settings.

Sunny Island has an "Equalize" function, normally used for FLA. Its voltage is set no higher than boost for VRLA. It may operate based on accumulated Ah (RTFM to find out), so maybe could be used to force a recharge even if battery voltage holds up above float.

 

[kts78]

Time will tell, this is for a school so the reality is the batteries get used very little (nobody is there at night), well pumps have a Lorenz switch so they can only run when the sun is producing enough energy to run them. Have water storage on the roof if needed. Trophy did not want the equalize funcion so voltage is set the same as float, and they gave me the float voltage they wanted....

 

[toms]

Time will tell, this is for a school so the reality is the batteries get used very little (nobody is there at night), well pumps have a Lorenz switch so they can only run when the sun is producing enough energy to run them. Have water storage on the roof if needed. Trophy did not want the equalize funcion so voltage is set the same as float, and they gave me the float voltage they wanted....

I’m keen to know more about the lorenz switch. I’ve been searching for something that will only allow a load to run when enough PV generation is available.
Cheers!

 

[kts78]

Sorry I spelled it wrong- it is a Lorentz sun switch.

https://www.solaris-store.com/telechargement/notice/notice_GE4000795.pdf

 

[kts78]

I’m keen to know more about the lorenz switch. I’ve been searching for something that will only allow a load to run when enough PV generation is available.
Cheers!

Hey just to let you know the Lorentz sensor is working perfectly. I have it connected directly to the vfd drives on our well pumps, then adjusted it so they only can come on if the solar is producing more than what they consume. We may eventually hook more loads but for now we have more than enough power for everything-- it is mostly protection in case somebody leaves the water on we don't have 2 well pumps running all night

 

[toms]

Hey just to let you know the Lorentz sensor is working perfectly. I have it connected directly to the vfd drives on our well pumps, then adjusted it so they only can come on if the solar is producing more than what they consume. We may eventually hook more loads but for now we have more than enough power for everything-- it is mostly protection in case somebody leaves the water on we don't have 2 well pumps running all night

Could you please send me a link to what you are using?

Cheers!

 

[kts78]

 

[Consumerbot3418]

I’m looking for something similar to that switch, but that switches based on frequency. Ideally, it could be programmed to turn on when the frequency exceeds a specified threshold for a length of time. That way, when I’m producing more solar than I can use, attached loads will run, then switch off again automatically when the frequency drops again. This seems like something that would be useful for anyone with off-grid Solar that implements frequency shifting.

There are smart plugs that can be flashed with Tasmota or ESPHome, but I’ve yet to find one that counts frequency.

 

[Hedges]

If you're using Sunny Island, one option for the relays is based on surplus power available.

I thought there were frequency based load controllers for SI but haven't found any commercial ones.