Sunny Boy 7.7s keep going off line.

[SilverbackMP]

All, I am hoping you can help me troubleshoot what's going on with my system.
Currently I'm on the other side of the globe don't have remote access. (I was supposed to be return within a couple of months but that hasn't happened).

System consists of

3x Sunny Boy 7.7s
4x Sunny Island 2P2S
REC Master BMS with slave BMS and batters made up 230AH CALB cells.

Since we commissioned them, they have been going offline about once a week.
Usually throwing out errors 501:

"The power frequency is not within the permissible range"

SMA - Customer Community

Now they won't stay on line more than a couple of minute and one is also throwing an Error Code 4301.

SMA Error Code 4301: Explained

CharacteristicsManufacturer: blog

www.renvu.com

It kicked off long enough that it drained the batteries (they have been staying in the 90% range). I THINK that is what happened anyhow. Possibly my mom didn't check soon enough? Although she checks several times a week (she is still on their old Outback system; we aren't going switch her power until we prove this out. My shop is on the SMA power; only constant load is a newer upright freezer).

I think I have multiple issues as most of the cells are 3.3 but one is at 2.8. That 2.8 v cell (I think) caused all of the batteries to disconnect as it was set as the low limit in the master BMS. So we turned the battery with the wild cell completely off (off switch on the slave BMS and switched off the battery breaker to the bus bar). That helped the system stay on for a few minutes longer and it started getting a charge. Then several minutes later the Sunny Boys stopped working. And the whole system went down (again).

We have strings of 12 Aptos 370 watt panels going into each A and B MPPT inputs. Rated Open Circuit Voltage per panel is 40.8. Here are full specs:

https://signaturesolar.com/content/documents/APTOS/1504004-specs.pdf

We aren't using the C port of the Sunny Boys. Each string has been averaging around 460v on a sunny day.

Is it possible that we are violating maximum voltage for the Sunny Boys and this is causing the issues?

I wouldn't think so:

Rated MPP Voltage range: 270 - 480 V
MPPT operating voltage range: 100 – 550 V
Maxium voltage: 600v




All three inverters feed into a GE (I think) 225A panel. Could be the breakers causing issues with the Sunny Islands and they are going ape shit causing problems with the Sunny Boys? I know @Hedges had issues with breakers and different resistances in the past and switched to MidNite Solar 60A breakers. But this completely offgrid and I think his issue had to do with grid tie and also breakers being thrown. We haven't had that problem.

Any ideas?

I am going to send a link to my electrician so he can monitor (former industrial electrician, retired power plant administrator, now does a mixture of excavation and electrical, leaning towards industrial/commercial/agricultural).

 

[SilverbackMP]

Also, I can't view any data. I have Data Manager M, but I didn't get a chance to configure it and figure it out before I left. We can easily view the BMS locally via WIFI. Again, I didn't have a chance to build a WIFI network so I could monitor it remotely but my mom and electrician can easily log in locally.

We commissioned the equipment using my laptop and an ethernet cable.

 

[SilverbackMP]

Going to order either the EG4 48v 18.9A Battery Charger or the Charverter (out of stock, supposed to be shipping at the "end of October) to get some power back in the batteries. That's going to be a major pain in the ass - either for me or my electrician. Pulling them out of that iron maiden I built for them (I've posted that image so many times on the forum, I don't feel like posting it again). If I could get the contactor to close on the REC BMS, units, I could just stick an anderson connector on the end of the charger cables and possible not remove them completely from that steel coffin.

 

[SilverbackMP]

This was the build post. Missing a shot of the main breaker box. But the Sunny Boys wire into the AC bus bar in the breaker box. The Sunny Islands also tap into with around 60A breakers (I don't remember the exact specs, either GE or Square D; I can't remember what we went with).

My SMA system install so far and precharge questions

Here’s some photos of my install so for. First we have the panel mounts. It’s three separate Sinclair Skymounts 2.0 that will hold seventy two 375 watt panels with twelve each in series to produce just shy of 600v each string on an extremely cold/sunny day. I split the mounts into three to...

diysolarforum.com

 

[SilverbackMP]

I'm thinking about trying 3 strings of 8s panels per inverter and seeing how the SBs behave. If that works better, I'll need to pull more wire (through my extra conduit). Thoughts?

 

[BKY2003]

The power frequency is not within the permissible range"I have had that happen to my Sonny boy 6.0 and 5. It end ed up being the power company being out of range. I think you can adjust the range, if you find out that’s the problem.

 

[Hedges]

Sunny Boy or Sunny Island went off line?

Running battery down sounds like Sunny Island disconnected from grid. And if Sunny Boy disconnects, then you're running from battery.

For reasons not explained, SMA America recommends configuring SB -41 for "island" when used in grid-backup system behind SI. That disagrees with documentation from SMA Germany.

SI defaults to running down to 59 Hz, which keeps UL-1741 SB offline. But should return to 60 Hz eventually.
SB set to Rule 21 would have wider frequency, should remain connected. I widened SB 5000US frequency to the Rule 21 limits.

Above 61 Hz, Rule 21 would drop power to 0%. But might also disconnect after a while. SI overshoots, so I would be inclined to increase allowed frequenct to 61.5 Hz (power would still be 0% above 60 Hz.)

But you're offgrid. Are SB configured for island/offgrid? They ought to be fine set that way. I haven't tried my SB -40 in those modes yet.

Voltage and current are within limits, should not be a problem.
My problem with breakers involved paralleled SI, and current was not split evenly when passing through from grid.
Your SB only seeing parallel breakers on output should have no issues.

Maybe your BMS is requesting lower current or voltage. Reduce connected SB and PV, see if it hovers between 61 Hz and 62 Hz, regulating desired current. If it needs to cut current it would swing up.

 

[SilverbackMP]

The power frequency is not within the permissible range"I have had that happen to my Sonny boy 6.0 and 5. It end ed up being the power company being out of range. I think you can adjust the range, if you find out that’s the problem.

I’m off grid. No generator attached (yet, it’s still on the old system). The Sunny Islands control the grid.

 

[SilverbackMP]

But you're offgrid. Are SB configured for island/offgrid? They ought to be fine set that way. I haven't tried my SB -40 in those modes yet.

Yes they are...but there were one or two settings we had to take an educated guess about...sigh...I wish I would have had time to test it all out and get things dialed in.

 

[Consumerbot3418]

Don't know if you got this sorted yet, @SilverbackMP , but I've got the same setup as you, and may have experienced a similar issue. In my case, it looks like it ended up being a power quality issue (caused by IQ7 microinverters). I just opened a thread about it here:

Off-grid problems with Enphase IQ7 microinverters, SMA Sunny Islands, and Sunny Boy

I'm writing to share my recent experience with trying to add AC coupled PV to my existing Sunny Island and Sunny Boy system, in case it proves useful to anyone. Ideas and suggestions welcome! Backstory/set-up: I had a DC Solar trailer with 2kW on-board PV, DC coupled via Midnite Classic. No...

diysolarforum.com

It would be handy if you could check the "instantaneous values" to see what frequency the Sunny Boy is "seeing". It's supposed to back off power output as the frequency is shifted away from 60Hz (reaching 0 output at 62Hz), but in my case, it was derating even at 60Hz indicated on the Sunny Boy and the Sunny Islands. You can also see the Sunny Island's frequency on Compact Meters. That way, you could confirm the Sunny Islands are commanding the frequency out of range, and then you'd know for sure it was an issue with the battery/BMS.

Since we've got a similar setup (aside from the BMS--mine is on FLA), I'd be happy to answer any questions about how SI/SB interact. But the default settings in "SMA Island" ought to work fine...