Skip to content

Tag: solar inverter

SMA Core 1 inverter loses serial number!

Ever had an issue with SMA inverters losing their serial number? Here’s how to fix it!

This is an example of this happening to me recently, and I’ll give some more details below the video, if you’re struggling with this same issue.

I’ve only ever seen this happen on the first iteration of the Core 1 inverter, the -40 model. The symptom is a wifi signal from the inverter that’s showing a “0900” number in the SSID. For instance, in a normal SSID, I’d expect to see the name be “SMA3000XXXXXX”— basically, “SMA”, plus the serial number visible on the exterior inverter label. But when the inverter loses its serial, it makes up a completely different serial for itself, usually starting in “0900”. In my case, I was seeing “SMA0900022963”.

This issue can cause problems with communication and general administration of the device, so it should be fixed, if possible. However, I’ve never seen this issue be responsible for lost power, so it’s a low-level problem, in the grand scheme of things.

The fix for this can only be accomplished through Level 2 of SMA’s tech support (call +1 (877) 697-6283). Level 1 will get your information, tell you your case number, and send you to Level 2.

Level 2 will need to screen-share with your laptop (Windows only), while your laptop is on the same network with the inverters themselves. You need to visit the login page of the inverter, but instead of the ending url being “login” (i.e. “https://<IP-Address-of-inverter>/#/login”), it needs to be “loginadvanced” (i.e. “https://<IP-Address-of-inverter>/#/loginadvanced”).

From there, to log into the “Service” user group, SMA’s tech will need to generate a password from that serial number you saw in the WiFi SSID earlier. In my case, “900022963”. There’s often a lot of confusion from the technician at this part. They’ll be fine, they’ll figure it out eventually. Last I knew, their password generates from the “serial number”, WITHOUT any zeros at the beginning.

Once the Service user group has been logged into, the only thing that needs done is typing in the correct serial number in Parameters->Type Label->Type Label->Serial Number.

Easy peasy, but you’re heavily reliant on that password from SMA for this fix.

Issue Solved: Fronius MPPT1 dropping production

I’ve been fighting with two identically installed Fronius Symo Advanced (10kW) inverters over the last month, and I think I’ve finally fixed it. It’s very strange, and seems to be an issue in the firmware of the inverter, itself.

The installation looks like this. They are two carports (only one is pictured), identically oriented, with north, south, east, and west arrays. The east and west arrays are smaller and hooked up to a Fronius Primo 3.8 on each carport, obviously using different MPPTs for different arrays. The same thing is the case for the north and south arrays: they’re hooked up to a Symo Advanced 10.0 at each carport.

The problem is that MPPT1, hooked up to the north array on each carport, drops off during high irradiance days. Check it out.

You can see when it starts producing in the morning, drops to nothing, then later in the day, it jumps back up and starts producing. Sometimes it takes until after noon, and sometimes, like pictured above, it comes back up when the irradiance dips and MPPT2 produces less for a bit.

This only happens on higher irradiance days with good, bright sun, and on both carports. On cloudier days, both north and south arrays on both carports produce equally, as you’d expect with diffuse sun.

Fronius tech support was no help with this one. We made sure firmware was up to date (fro34310 at the time, for those following along), but beyond that they were extremely confident that there was something wrong with our wiring or our array setup, but couldn’t give me proper direction. It may have simply been the one tech I was talking to, but he was extremely frustratingly not budging on his assessment. It doesn’t help that there are no error codes triggered with this problem.

In troubleshooting, I couldn’t nail any issues to our set up for rapid shutdown devices; everything on site is rated to work with each other and is set up properly. Had some previous issues with dueling RSD transmitters tripping arc faults that I got sorted, so very confident that’s not an issue any more.

When I was onsite, however, I was able to shut off DC to the inverter and turn it back on within about 10-20 seconds, and the inverter jumped up to the proper production on all strings, so it would seem there’s nothing instantaneous in the array that’s causing MPPT strangeness.

Finally, I swapped MPPTs between arrays, putting the south array (highest producing) on MPPT1 and the north array (lowest producing) on MPPT2. After giving it some time, I think this one change solved my issue.

You can see in comparison to the first graph, that the north arrays seem to have no more issues with dropping off in production. The south arrays didn’t have the irradiance on this day that they had in the previous graph, but it’s enough that the north arrays would have dropped off if they were wired as they were originally.

My reckon is that this is directly related to the inverter wigging out when MPPT2 gets 5x or more the production of MPPT1, and only resets when MPPT2 stops rising. I’d imagine that most installations would put the main and highest producing arrays on MPPT1 by default anyway, so this issue would be very rarely seen. If you’re having this issue, try making sure MPPT1 gets the most production between the two, and it might fix it for you.

Weird weird issue.

Solectria inverter power cycling

At issue is a Solectria (now owned by Yaskawa) PVI 85 KW inverter that’s turning off and on. I was able to witness it powering off and on in the morning when I got there, but as the day went on, it stayed on. Errors present are “Power Derated” and “AC Contact Open”.

Most recent was the AC contact open error, and very likely the main issue is the AC Contactor, but that “power derated” error makes me nervous that the DGMI is bad, too.

The unfortunate thing about the DGMI possibly being bad is that Yaskawa no longer replaces DGMIs.

It’s probably still likely that the contactor replacement is worth the risk. I’ll update as I know more.