SunGold Power SP6548 Flickering lights after new install

[nofear72784]

I have an E2 and I am an electrical engineer by trade yet he refused to issue me a permit. I had all the required drawings and engineering reports but I am not an "experienced solar installer or a licensed company" so he refused. Long story, but after months of back and forth it was just easier to pay someone else. TBH I installed 98% of it and all I paid for was the final hookup and pulling of the permits. The city has a serious racquet with a few install companies that give a kickback to the city in the form of donations to parks etc so it is legal. If you use them you get an inspection within a week. My neighbor did not use one of those companies, been waiting since may for a final inspection to commission the system.

 

[Zwy]

AC input is wired in. On ac bypass the neutral and ground are unbonded. In battery mode they are bonded, so I lifted that bond per the instructions from Reliance and NEC. The inverter neutral goes to the reliance panel which is just a pass though to the main buss bar. I can put the screw back in but then I wouldn't I have 2 loops?

Do you have EGC on both input and output of the inverter?

I'm looking for possible loops. The ground on the units is pass thru on input and output. You could measure for current on neutrals and grounds for input and output of the inverter. As your scope has not yet arrived, this would be some testing you can perform that might point to an issue.

I am not a huge fan of the grounding screw removal. There are better ways of wiring in this inverter with the addition of a new main panel and making the main panel a subpanel. The addition of a 3 pole transfer switch is another. Plenty of discussion in the past concerning this subject, everyone wants the cheap way but when problems arise they always overlook how it can't be the result of being cheap.

 

[nofear72784]

Main input is hot, neutral ground from main panel. Output is hot, neutral ground to the transfer panel. Inside the transfer panel they pass through the neutral and ground right back to the main panel. The bonding in my system is back at the main disconnect which is on the outside of the house. In passthrough there is no flickering. So, the power travels the same path through the transfer switch as it would minus the inverter which is leading me to an inverter issue.

 

[nofear72784]

If the unit needs to be pulled for this issue I will be glad I went with a transfer as I can easily go back to line power while I await a replacement. But, I do know what you mean.

 

[Zwy]

Main input is hot, neutral ground from main panel. Output is hot, neutral ground to the transfer panel. Inside the transfer panel they pass through the neutral and ground right back to the main panel.

I'd remove the EGC on the inverter output.

The bonding in my system is back at the main disconnect which is on the outside of the house.

So, there is a bond at the disconnect and in the main panel?

In passthrough there is no flickering. So, the power travels the same path through the transfer switch as it would minus the inverter which is leading me to an inverter issue.

Any HF inverter can cause flicker. Read this thread. https://diysolarforum.com/threads/n...using-led-light-pulsation-flicker-help.43534/

Having said that, if there is a loop in the circuits, then the inverter may have a hard time regulating output. The same is when the unit is modified by screw removal instead of having N-G bond at the inverter under inverter power. As an EE by trade, you should know this.

 

[nofear72784]

I'd remove the EGC on the inverter output.



So, there is a bond at the disconnect and in the main panel?


Any HF inverter can cause flicker. Read this thread. https://diysolarforum.com/threads/n...using-led-light-pulsation-flicker-help.43534/

Having said that, if there is a loop in the circuits, then the inverter may have a hard time regulating output. The same is when the unit is modified by screw removal instead of having N-G bond at the inverter under inverter power. As an EE by trade, you should know this.

So you think I should try lifting the ground on the output? There is a bond only at the main disconnect. The main panel has 4 service leads that separate the neutral from ground. In my day to day I work with a team that designs automotive and aerospace components. I have not messed with residential A/C since my journeymen days. Seems I am a bit rusty. Without any diagrams I was not assuming anything. I did inquire about ground passthrough and was told to "connect it per the manual". There seems to be quite the language barrier with their technical support. I see what you are getting at and it can't hurt to try it.

 

[Quattrohead]

Why are you concentrating on the inverter so much ? Certain LED bulbs are known to flicker with dimmers/inverters or even a full moon lol.
Surely trying a few different LED's will find a solution quicker, easier and cheaper than messing around with the inverter.

 

[nofear72784]

because it's over 40 fixtures and they do not flicker when directly attached to another inverter or when the system is on grid or generator. the bulbs and dimmers are all expensive Philips LED's in the dimmables and cree's in other locations. Dimmers are Lutron or Levitron LED dimmers. Changing out 40 plus bulbs that are already work fine in all other instances seems like an expensive shot in the dark.

 

[Quattrohead]

1 fixture and buy every LED that HD/Lowes has and try them all. You can return them if they are no good. You might find a good one.
Heck, I have a pair of SP6548 on order, I will do the test when I have everything.

 

[nofear72784]

Lowest quantity would be 6. These are all LED can's. We have them in the kitchen, family room, hallways and bedrooms. I will see what happens when I pull the ground from the output as recommended and see what the scope shows. I should have continuity checked the input and output ground but between the inspector, installer and emails from the manufacturer saying connect it I figured it was not passthrough. I just came across Will's video saying that they are indeed connected! Which means I am creating a ground loop on the output side. Why oh why are there no wiring diagrams in the manual....

 

[SparkyJJO]

I did not realize that there are two ground connections on that inverter. That's bonkers.

 

[nofear72784]

Didn't even dawn on me until Zwy questioned it. 3 wire in and 3 wire out. If it will fix the flickering? We shall see

 

[Zwy]

So you think I should try lifting the ground on the output?

Definitely. It isn't needed as the input has ground back to the N-G bond.

There is a bond only at the main disconnect. The main panel has 4 service leads that separate the neutral from ground.

As you only have 1 unit, there really wasn't a need for removing the ground screw if there is a subpanel after the inverter if the transfer switch was 3 pole and switched neutral. The concern with 2 units providing split phase is the N-G bond in both inverters will cause a ground loop and objectionable current on the EGC between the 2 units. This is not an issue with a 3 pole transfer switch and the 2 inverters close together, the only objectionable current will be between the 2 inverters, only a few feet. With 1 unit, this isn't a problem unless the transfer switch has a pass thru neutral. That is why a 3 pole neutral switching transfer switch is the preferred choice. The AC input of the inverter does contain a 3 pole neutral switching transfer switch. You would be better served by having a subpanel (unbonded) after the 1 inverter and running the neutral for the panel thru the inverter. The ground screw would remain and N-G bond would be supplied by the inverter. In bypass mode, the N-G bond would be at the main disconnect.

If you want to install a transfer switch for a generator, it would go between the inverter and the subpanel. Neutral would pas thru the inverter and be switched.

In my day to day I work with a team that designs automotive and aerospace components. I have not messed with residential A/C since my journeymen days. Seems I am a bit rusty. Without any diagrams I was not assuming anything. I did inquire about ground passthrough and was told to "connect it per the manual". There seems to be quite the language barrier with their technical support. I see what you are getting at and it can't hurt to try it.

We had many discussions and diagrams here in various threads concerning the N-G bond in these inverters. Some are quite lengthy but it gives the basis on how conclusions were arrived at.

 

[Zwy]

I did not realize that there are two ground connections on that inverter. That's bonkers.

Not really. If the inverter was to be used completely off grid, the output ground would be utilized and N-G bond occurs at the inverter which is source.

On grid backup with bypass power, the input would be utilized and allows N-G bond before the inverter in bypass mode.

This allows the unit to be wired for both scenarios.

 

[Zwy]

Didn't even dawn on me until Zwy questioned it. 3 wire in and 3 wire out. If it will fix the flickering? We shall see

I would get neutral to 0V potential and then see what occurs. 0V potential depends on system bonding and how current returns to source.

I still prefer the N-G bond at the inverter regardless of prevailing opinion in this forum. It is source when used for power and not having N-G bond at the source can lead to stray voltage potential in a system. Time will tell if my stance is correct.

 

[nofear72784]

Ground removed from the output, no change in behavior.

 

[Sky Noris]

I highly doubt grounding to be the issue. The most likely thing for this is just the inverters power characteristics. This is a really dumb question but did you verify the inverter is set to 60 hz vs 50 hz?

 

[nofear72784]

Well the wrong scope came in.. love Amazon.. smh but you can still see the bottom of the wave. On inverter power it's wiggling around like a wet noodle. On grid power, rock steady

 

[Lilikoi_Heavy_Industries]

Well the wrong scope came in.. love Amazon.. smh but you can still see the bottom of the wave. On inverter power it's wiggling around like a wet noodle. On grid power, rock steady

And what happens when you remove grid power?

A similar thread that I read said that everything worked great as soon as the grid input was removed and it has me wondering. I'm sorry if you already answered this! I've been following the thread and forgot if that's the case.

 

[nofear72784]

I did not, let me check

 

[nofear72784]

Wish I could get a good scope from work but this proved the point. No change removing the grid side

 

[nofear72784]

 

[SparkyJJO]

That's a crummy looking waveform.

 

[SpongeboB Sinewave]

nofear72784, your scope is clipping. Will need to re-capture this with a higher voltage range.​

 

[jeremyee]

Did you check your L1 and L2 voltages both to neutral and ground? Someone had a similar issue and his neutral was floating off balance for some reason.

I had this same issue when connecting a generator to supply power to the entire house. What solved my issues was disconnecting the ground to neutral bonding at the generator since the ground to neutral bond was at the load panel/ breaker box. Also check the voltage on each phase if you have multiple phases.


I was told by many electricians and engineers bonding was not the problem but it resolved my issue. Might be worth a check on the inverter bonding