SunGold 6548 fault code 86

[garetwo]

I am an electrician and whether I should be posting in the beginner section, or a thread specific venue, is a quandary at times for me.

SunGold has been good at responding to emails with questions, I am sure I am testing their patience. I never asked about a warranty, so this is not a warranty thread, it is a thread to isolate the problem.

A friend is working toward getting off-grid. He had two SunPower 6548's that were working in parallel as utility assisted inverters He recently added two more 6548's (all are the older, lower voltage input models) as well as four 12.8v Jita 300ah batteries to the twelve he had connected. There was a lot of discussion on this battery arrangement already.

After connecting the four inverters and all of the batteries, things worked, but very briefly. As I was driving home, his power got "dirty" with motors sounding funny, etc. Ultimately, he lost power and all four inverters showed fault code 86 AND he cannot turn the inverters back on. We for sure had setting 28 at 2P1 and 2P2 (@180). Here is SunGold's answer to some questions and their troubleshooting sequence which we will do today. I have to drive up there, where they are running off of generator to part of the home - the bulk runs off the inverter outputs.

(after watching several videos) Questions and answers:

1. Though most cases show the inverters unable to run if only one of them is provided power, with four inverters, may we turn off all inputs and outputs to one inverter in each phase and just run two inverters (one on 2P1 and one on 2P2) without changing communication cables?
Or, must we reconfigure communication cables as if there are only two inverters?

2. May current sharing cables stay in place?

3. Should we feed utility AC in with single pole 60-amp breakers or should the breakers be 2-pole?

4. Should we feed AC out with single pole 60-amp breakers or should the breakers be 2-pole?

5. Will the inverters keep running if one loses utility AC power, but all still have battery?

Fairly quick response but they still kindly apologized for the time it took:
FROM SUNGOLD
Sorry to keep you waiting so long.

1. With four inverters, we can turn off all inputs and outputs to one inverter in each phase and just run two inverters (one on 2P1 and one on 2P2) without changing communication cables.

2. Connect the current cable to the same phase, and do not connect the current cable to different phases.

3. We advise 2-pole breakers for utility AC in

4. We advise 2-pole breakers for AC out

5. The inverters keep running if one loses utility AC power but all stills have battery

6. the inverters keep running if one loses battery power but still has utility AC

This next part is specific to the fault 86, I post in case there are other things I should consider. Again, their warranty comment was unsolicited:

About your 86 code, could you please don't use your battery in parallel first? We need to make sure every single inverter is in good condition.

Could you please test your inverter separately (separately means all inverters don't share any cables with others) to confirm if they can be turned on when only connecting the inverter?

Could you please tell us where the customer bought the inverter? From Amazon or our website? We need the order number to execute our warranty.
END OF REPLY FROM SUNGOLD

I have sent them a question on not having the batteries in parallel for testing, but all of the batteries connect to a common bus, not a set of four to each inverter. Can we do that? What would be the reasoning to disconnect three sets of four batteries from the bus?

 

[garetwo]

Well, it has all worked out, they are working fine...well at least for 6-1/2 hours now. I am not sure what was going on, but we ran each inverter individually as a stand-alone 120 unit, did that for each one (maybe 15 minutes each), reconnected everything. Went through every setting to make sure each inverter was right....they work. It had to be a setting we did wrong the first time around - very embarrassing.

Oh, they also erred on taking battery banks out, they meant take all of the inverters out of parallel...we took the batteries out because they replied after the fact.

 

[Skypower]

Well, it has all worked out, they are working fine...well at least for 6-1/2 hours now. I am not sure what was going on, but we ran each inverter individually as a stand-alone 120 unit, did that for each one (maybe 15 minutes each), reconnected everything. Went through every setting to make sure each inverter was right....they work. It had to be a setting we did wrong the first time around - very embarrassing.

It’s not like you do four communicating inverters every day. I think you should cut yourself some slack.
If haven’t already, I’d install a couple of whole house surge protectors. One on the grid side and another on the output side to protect the inverters from both sides. 70+ percent of damaging surges originate from something from the load/distribution side. These are very powerful and inexpensive. They have internal thermal and current protection so they have instructions on how to wire direct buss or to a breaker.

 

[garetwo]

Great idea...one I should have thought of. I did not even look at where the utility transformer is relative to the home, mine is super close AND I have the surge protector AND I have never installed it. Oh, just so you know, they do not like single pole 60's, they prefer two-pole, but now I want to know if there should be 4-pole and take out all four...

 

[Skypower]

I guess we’re talking about the lines out and in. I’ve got a double 60 for my two inverters and probably would have gone with a 70 next time but I’m only using 6THHN on the line out/in and they are very short runs ( other side of wall). Never tripped, never had an inverter shut down from load issues. Dirty grid power shut down, once. Not since the surge protector.
A four pole? Got me thinking of the pros and cons with that idea. Don’t know.

 

[garetwo]

Well, if four is optimum safety for "one goes we all go, then it would beg what do if the full six were installed. It would seem one needs to go one way or the other, protect them all or isolate and go with the rest. If isolate is the answer, then shouldn't single pole devices be used for protection? If it is protection, how does two 2-poles protect four inverters and why take out two if only one has some weird fault?

 

[Skypower]

I just tossing it in the air but how about two, 2 pole breakers. One bad inverter will take out two inverters, one line one and one line two inverter. Still have split phase and half the system up if SHTF or shut down half the system for reserve or backup. I’ve heard that people have ran three inverters on split phase, just two are on one line. Kinda weird but I’d guess you could run more off balanced load.I’d guess you’d need a four pole and one tap unused for that scenario.

 

[garetwo]

Sort of exactly...how is that?!

If we can do a three in a 1 and 2 mix, then are other combinations ruled out or are all possible scenarios ok, including single phasing?

I know there may be a lot of downstream 2-pole breakers, so equipment that will not like one leg, but (may as well go to an extreme in writing), could not all 2-pole breakers go into their own panel with a shunt trip main breaker taken out if a voltage monitor "sees" loss of one leg. S

o, now all 240Vac loads are protected and out of the picture. So, sticking with 4 because less combinations to enumerate, what is wrong with 1 and 2, 2 and 1, just 2 (on one phase), or even just 1 on one phase?

Saying they prefer 2-pole almost seems like perhaps not a lot of thought went into it and just think taking out both is best.
Is back-feed into a non-operative inverter a potential issue? a failed AC input to one inverter, taking out its paired opposite, leaves their outputs tied to the outputs from the active two. Or, maybe there is great reasoning.

I’ve heard that people have ran three inverters on split phase, just two are on one line. Kinda weird but I’d guess you could run more off balanced load.I’d guess you’d need a four pole and one tap unused for that scenario.

This is even in their manual. It seems super odd that anyone would deliberately unbalance a system unless doing it right would require 4 inverters and they just could not afford it.

 

[garetwo]

This is way off topic, is that ok? I see moderators "counseling" others and even deleting posts

 

[Crowz]

This is way off topic, is that ok? I see moderators "counseling" others and even deleting posts

If someone goes off topic on YOUR thread then I could see that. Since its your thread your the one picking the topic