automatikdonn
Becoming Offgrid
So as many of you may know I posted a thread about my neighbor having an issue with his EG4 18k Inverters.
System Information:
60 Panels
2 EG4 18k in parallel
No Battery
Summary of the issue:
When the grid connection is removed, the inverters would begin to provide 400v to the mains input side of the inverters.
The system was professionally installed and all wiring was correct.
The system was reporting everything was fine. No faults or errors were reported. The inverters were being recognized as being in parallel.
Diagnosis:
EG4 got into the system and checked the configurations and found nothing wrong.
EG4 guided us to first check the parallel cable. (Thank you EG4)
We found that the installer had used a cross-over cable that was likely bought from a Box store.
We made a new cable up that followed the proper standards.
Results:
Systems worked as expected. All commisioning tested passed.
Notes:
The inverters likely should catch that a cross over cable was used and not go into parallel mode.
Also, use the correct pinout if you are buying or making an ethernet cable. Not doing so could be dangerous, until a patch is released you could potentially have this problem.
I would like to call out @Markus_EG4. After checking the config, his very first troubleshooting step revealed the issue.
We plugged the factory cable in, executed the same test and it did exactly what it was supposed to.
Other:
Many people have asked why the old thread was deleted. The old thread essentially contained a bunch of speculation while we worked the root cause. In the interest of being as helpful to forum members as possible, this new thread was created to get people the problem and the answer in the OP. We are all here to help each other learn, grow and be the best community on the internet for DIY Solar.
The questions posed in the original thread were helpful as everyone was trying to QUICKLY get to the bottom of the problem. Many thanks to all of you for being so willing to donate your time and your brain to fix problems for essentially what are strangers to you. It's the difference that makes this place great!
Quick Links:
EG4 Response
https://diysolarforum.com/threads/eg4-18k-what-not-to-do-in-parallel.84679/page-6#post-1105159
The elephant in the thread:
These particular inverters could be bad and this issue could be isolated to only them. We do not have other gear to test against, so we cannot confirm the bug. I would ask someone from EG4 to come out and take a look. We are super close and this isn't a big ask IMO.
Before we speculate anymore - short of someone else confirming this bug (I don't have 10K to buy them and test - but will accept donations to do so
)
I think we should wait to see how this ends up shaking out. I think this is fair to EG4 and I think this is fair to the commmunity. We don't need to sour anyone without all of the facts. Right now we really only have one fact. These inverters do in fact exhibt this problem.
Signature Solar Response:
https://diysolarforum.com/threads/eg4-18k-what-not-to-do-in-parallel.84679/page-11#post-1105380
Evidence:
Here is a picture of the cable that caused the problem
Here is the video of the issue.
New developments:
Here is the pinout
diysolarforum.com
This cable is a specific type of crossover for going from T568A to T568B devices.
The specific pinout allowed the canbus connection to come up, while all the other parallel signals to be crossed.
https://diysolarforum.com/threads/eg4-18kpv-what-not-to-do-in-parallel.84679/page-21#post-1108780
System Information:
60 Panels
2 EG4 18k in parallel
No Battery
Summary of the issue:
When the grid connection is removed, the inverters would begin to provide 400v to the mains input side of the inverters.
The system was professionally installed and all wiring was correct.
The system was reporting everything was fine. No faults or errors were reported. The inverters were being recognized as being in parallel.
Diagnosis:
EG4 got into the system and checked the configurations and found nothing wrong.
EG4 guided us to first check the parallel cable. (Thank you EG4)
We found that the installer had used a cross-over cable that was likely bought from a Box store.
We made a new cable up that followed the proper standards.
Results:
Systems worked as expected. All commisioning tested passed.
Notes:
The inverters likely should catch that a cross over cable was used and not go into parallel mode.
Also, use the correct pinout if you are buying or making an ethernet cable. Not doing so could be dangerous, until a patch is released you could potentially have this problem.
I would like to call out @Markus_EG4. After checking the config, his very first troubleshooting step revealed the issue.
We plugged the factory cable in, executed the same test and it did exactly what it was supposed to.
Other:
Many people have asked why the old thread was deleted. The old thread essentially contained a bunch of speculation while we worked the root cause. In the interest of being as helpful to forum members as possible, this new thread was created to get people the problem and the answer in the OP. We are all here to help each other learn, grow and be the best community on the internet for DIY Solar.
The questions posed in the original thread were helpful as everyone was trying to QUICKLY get to the bottom of the problem. Many thanks to all of you for being so willing to donate your time and your brain to fix problems for essentially what are strangers to you. It's the difference that makes this place great!
Quick Links:
EG4 Response
https://diysolarforum.com/threads/eg4-18k-what-not-to-do-in-parallel.84679/page-6#post-1105159
The elephant in the thread:
These particular inverters could be bad and this issue could be isolated to only them. We do not have other gear to test against, so we cannot confirm the bug. I would ask someone from EG4 to come out and take a look. We are super close and this isn't a big ask IMO.
Before we speculate anymore - short of someone else confirming this bug (I don't have 10K to buy them and test - but will accept donations to do so
)I think we should wait to see how this ends up shaking out. I think this is fair to EG4 and I think this is fair to the commmunity. We don't need to sour anyone without all of the facts. Right now we really only have one fact. These inverters do in fact exhibt this problem.
Signature Solar Response:
https://diysolarforum.com/threads/eg4-18k-what-not-to-do-in-parallel.84679/page-11#post-1105380
Evidence:
Here is a picture of the cable that caused the problem
Here is the video of the issue.
New developments:
Here is the pinout
EG4 18KPV - What not to do in parallel
Nothing you can show or provide. You've just got an 8-pin RJ-45 cable that connects the two jacks in some order. What we're talking about is internal to the inverter, what function goes to each pin. That way we can determine if crossover cable is identical to no cable (except maybe for a ground...
diysolarforum.com
This cable is a specific type of crossover for going from T568A to T568B devices.
The specific pinout allowed the canbus connection to come up, while all the other parallel signals to be crossed.
https://diysolarforum.com/threads/eg4-18kpv-what-not-to-do-in-parallel.84679/page-21#post-1108780
Last edited:
