SMA Sunny Boy 2500 - manual reset after Earth Fault

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dougl

Member
Location
San Diego
I have an SMA 2500 with the GFI/Earth Fault error and replaced the CMS2005 SP3 module on the GFI board but still how the Earth Fault error. Documentation leads me to believe the inverter needs to be reset manually.

Does anyone have data on the manual reset procedure?

Thanks.
 
ATSman

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
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pv_n00b

Senior Member
Location
CA, USA
As far as I know a ground fault alarm has to be manually reset on inverters in the US. You have to go out, test the array for grounds, reset the inverter, see if the alarm is still there. It's a good reason to not have grounds in the array because they eat support time.
 
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dougl

Member
Location
San Diego
D

dougl

Member
Location
San Diego
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jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
This inverter is a little older than the ones I first started working with, but on those I don't remember anything other than replacing the fuse and turning the inverter back on.

Since you started off talking about replacing the board, I think everyone's assuming that the fuse is good and you tested the array to rule out a genuine ground fault.
 
G

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Consulting Electrical Engineer - Photovoltaic Systems
jaggedben said:
This inverter is a little older than the ones I first started working with, but on those I don't remember anything other than replacing the fuse and turning the inverter back on.

Since you started off talking about replacing the board, I think everyone's assuming that the fuse is good and you tested the array to rule out a genuine ground fault.
Click to expand...
This is the first mention of the GF fuse I have seen in this thread. Is it possible that the fuse wasn't replaced and that's why it won't clear the fault? Or does the CMS2005 SP3 module contain the fuse?
 
gadfly56

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
dougl said:
OK so I downloaded that version of the doc and on page 30 it just lists parameters accessed through a data link but nothing which states it's about a manual reset. Are you saying I will need a data link(Sunny Data) to do this? This inverter only has the display board on it.
Click to expand...

Did you follow the trouble shooting instructions in the manual? Removed the varistors and installed a jumper to rule them out?
 
D

dougl

Member
Location
San Diego
jaggedben said:
This inverter is a little older than the ones I first started working with, but on those I don't remember anything other than replacing the fuse and turning the inverter back on.

Since you started off talking about replacing the board, I think everyone's assuming that the fuse is good and you tested the array to rule out a genuine ground fault.
Click to expand...

Yes, the fuse was measured and so was the array but the replacement CMS2005 module was still throwing the Earth Fault error and I saw it on the output of the GFI board. Where I screwed up was attempting to force the system into NOT sensing a ground fault by pulling the GFI board output to Signal Ground(SigGND) using my meter in current mode(effectively a short). I failed to move the meter leads back to Volt/Ohm positions and tried to measure -12V rail on the GFI board and this shorted -12V to ground. It came back so I didn't blow the -12V power supply but when an OpAmp such as the CMS2005 has, gets only one rail voltage it will swing only to that side and I believe this put a higher signal on the GFI board's output and triggered the >1A GFI error( NUM-Idiff ). This error, once triggered, can only be cleared with a "manual reset".

So the first thing I have to do, after ordering another CMS2005, is to clear/reset the system so I can get back to the original Earth Fault.
 
D

dougl

Member
Location
San Diego
ATSman said:
Sorry, I sent you the wrong link.
Try this one:

http://pdf.wholesalesolar.com/inverter pdf folder/SMA SB2500U Manual.pdf

Page 30, Sect 4.2

Tony
Click to expand...

That worked! the reset magic is to initial test with the GFI fuse removed. Thank you!
I have both a new CMS2005 module coming and a used but functioning SMA-SB2500U so a quick swap of the GFI boards will prove either my initial GFI board repair was faulty due to a bad replacement module or there really is something else wrong with the main unit(doubtful). I expect the backup/replacement inverter tomorrow.
 
D

dougl

Member
Location
San Diego
dougl said:
That worked! the reset magic is to initial test with the GFI fuse removed. Thank you!
I have both a new CMS2005 module coming and a used but functioning SMA-SB2500U so a quick swap of the GFI boards will prove either my initial GFI board repair was faulty due to a bad replacement module or there really is something else wrong with the main unit(doubtful). I expect the backup/replacement inverter tomorrow.
Click to expand...

All is working! The used SB2500U from ebay came and I swapped the GFI boards and my SB2500U started up as if nothing was wrong.

So it would appear I received a bad CMS2005 module. Another one is on the way and I will R/R the original board with the new part and test it to see if it fixes the problem. We know what happened if it then works but if it still doesn't work then I will start looking at the circuit on the GFI board and see if there's something noticeably out of spec.

I also purchased a 3rd SB2500U which had the CMS2005 module replaced and still didn't work and will see what that GFI board is doing.

With a little luck and investigation we'll figure out the common failures and how to fix them so people don't have to throw away their inverters and spend lots of money on a new one.
 
ATSman

ATSman

ATSman
Location
San Francisco Bay Area
Occupation
Electrical Engineer/ Electrical Testing & Controls
dougl said:
All is working! The used SB2500U from ebay came and I swapped the GFI boards and my SB2500U started up as if nothing was wrong.

So it would appear I received a bad CMS2005 module. Another one is on the way and I will R/R the original board with the new part and test it to see if it fixes the problem. We know what happened if it then works but if it still doesn't work then I will start looking at the circuit on the GFI board and see if there's something noticeably out of spec.

I also purchased a 3rd SB2500U which had the CMS2005 module replaced and still didn't work and will see what that GFI board is doing.

With a little luck and investigation we'll figure out the common failures and how to fix them so people don't have to throw away their inverters and spend lots of money on a new one.
Click to expand...

Congrats!
You are now a Sunny Boy expert !! ;)
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I gotta ask... and I'm not trying to be snide, it's a genuine question ...

Was the time and expense worth it (for you? for the system owner?) compared to replacing the inverter with a new model and a new warranty?
 
gadfly56

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
jaggedben said:
I gotta ask... and I'm not trying to be snide, it's a genuine question ...

Was the time and expense worth it (for you? for the system owner?) compared to replacing the inverter with a new model and a new warranty?
Click to expand...

For this single instance, probably not. However, if he can leverage this experience to faster troubleshooting and less expensive repairs for future customers, probably yes.
 
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