EG4 6500 - stuck low PV voltage

[mountkay]

Hello!

I have 2x inverters, (running split phase). 3 strings of 340W panels, 2x strings of 7 panels and one of 6 panels.

Inverter 1 is receiving a 7 panel input and 6 panel input. Inverter 2 just receives a 7 panel input.

Inverter 1 will almost always have panel voltage above 90v.
Inverter 2 will sometimes hover around 90v in low light, and like one of the graphs says, it appears to be only getting 50% power.
I can shut off the DC disconnect to inverter 2 and turn it back on - then the voltage immediately jumps up from 90v to about 200v and I’m receiving 2x as much power.

For example: This morning Inverter 1 is pulling ~800 watts. So Inverter 2 should be about half that at ~400w (according to number of panels).
Inverter 2 is instead at 90v ~200w. After turning off and on the DC disconnect for inverter 2, the voltage jumps to ~200v and I am getting ~400w.

According to one of the graphs, there is a switch in amperage related to MPPT temp. I’m guessing this also has to do with the switch in voltage.

Why would inverter 2 be running at half power for so long and (from my understanding) waiting to heat up to 85deg before it increases voltage and goes to full power output?

And why does turning the DC disconnect off and on cause it to do this immediately?

As long as there is about 200w of sun on Inverter 2’s string of panels, it will not revert to 90v. But on low light days, sometimes after I trick it into going to higher voltage, it reverts back to 90v range. This is annoying because I am only getting ~50% power when I need it the most.

Can anyone “shed some light” on my situation?



EDIT: Master Index where I will link other threads where this issue is being discussedv

EG4-6500 losing clock and MPPT issues

system is: two inverters configured split phase, each with 3.4kW of panels connected to PV1. The 2P1 inverter loses about an hour per day on its clock, the 2P2 inverter does not. The 2P1 inverter's MPPT input "idles" around 285W until I interrupt the input, then it instantly increases to match...

diysolarforum.com

Signature Solar Customer Support and EG4 6000EX inverter issues

It has now been a month since I originally contacted Signature Solar about my issue with my inverter. I have had multiple issues, one of which was resolved with their latest firmware update, so that won't be discussed. The biggest issue anyway is the charge controller failing to produce what it...

diysolarforum.com

EG4-6500EX-48 Issue

PV Input issues: (1) I have to restart or power off the inverter daily then power it back on in order to get the proper solar power from PV1. As as example to today, this morning PV1 was showing a measly 100+ watts of power coming in, I knew this wasn't correct, although the sun just crested...

diysolarforum.com

New EG4 6500-EX firmware 79.66 - no change log

Just found a new firmware but no change log (just 2 days ago I've just updated my 6 inverters to 79.63 :rolleyes:). Any ideas about what's changed in 79.66?

diysolarforum.com

 

[sunshine_eggo]

Links to manuals are better than snippets.

First graph is for AC output power and not related to the MPPT. If the AC input voltage is low, the AC output is derated between 80 and 110V.

Second graph is a temperature de-rating of the MPPT. If it heats to 85°C, it will cut to 9A max. It has to then cool to 75°C before it will return to 18A.

Neither graph appears relevant to your issue.

I don't have an explanation for the behavior except for potentially a lack of demand in low light conditions or a flawed MPPT algorithm. The PV disconnect interrupts the typical voltage behavior the MPPT sees transitioning from dark skies to ambient light. By disconnecting, it allows the panels to achieve max voltage. When reconnected, the MPPT sees a gob of voltage and begins drawing it down to find the MPP.

If solar intensity increases, does the 2nd inverter begin charging as you would expect on its own? I would expect the MPPT to figure it out at some point after a MPPT discovery sweep.

 

[mountkay]

Links to manuals are better than snippets.

I’ll keep that in mind for the future.
Here’s a link. Graphs are on pages 6 & 8.

https://eg4electronics.com/wp-content/uploads/2022/10/EG4-6500EX-48-Manual.pdf

Thanks for your response. Everything you said makes sense.

If solar intensity increases, does the 2nd inverter begin charging as you would expect on its own?

Yes at a certain point when there is enough sunlight Inverter 2 charges as expected.

Perhaps I should just update my firmware. I didn’t have any issues other than this so I didn’t want to try updating.

Maybe the 2 inverters are acting different because Inverter 1 is an older model (pre-Nov 22, with old input/output terminals and N/G bond screw).
Inverter 2 was ordered mid Nov 22 (has new input/output terminals and reportedly no N/G bond screw).

Inverter 1 is at:
U1 - 79.02 (Main CPU Version)
U2 - 61.06 (Secondary CPU Version)
U3 - 00.00 (Wi-Fi Version)

Inverter 2 is at:
U1 - 79.03 (Main CPU Version)
U2 - 61.02 (Secondary CPU Version)
U3 - 00.00 (Wi-Fi Version)

 

[sunshine_eggo]

Firmware updates either go smoothly, or they seem to blow up in your face. If this is a minor thing where you're only losing 30-60 minutes of optimal charging from one string, I wouldn't worry about it UNLESS I KNOW FOR CERTAIN, that the firmware update will rectify it.

 

[SignatureSolarJames]

Hello!

I have 2x inverters, (running split phase). 3 strings of 340W panels, 2x strings of 7 panels and one of 6 panels.

Inverter 1 is receiving a 7 panel input and 6 panel input. Inverter 2 just receives a 7 panel input.

Inverter 1 will almost always have panel voltage above 90v.
Inverter 2 will sometimes hover around 90v in low light, and like one of the graphs says, it appears to be only getting 50% power.
I can shut off the DC disconnect to inverter 2 and turn it back on - then the voltage immediately jumps up from 90v to about 200v and I’m receiving 2x as much power.

For example: This morning Inverter 1 is pulling ~800 watts. So Inverter 2 should be about half that at ~400w (according to number of panels).
Inverter 2 is instead at 90v ~200w. After turning off and on the DC disconnect for inverter 2, the voltage jumps to ~200v and I am getting ~400w.

According to one of the graphs, there is a switch in amperage related to MPPT temp. I’m guessing this also has to do with the switch in voltage.

Why would inverter 2 be running at half power for so long and (from my understanding) waiting to heat up to 85deg before it increases voltage and goes to full power output?

And why does turning the DC disconnect off and on cause it to do this immediately?

As long as there is about 200w of sun on Inverter 2’s string of panels, it will not revert to 90v. But on low light days, sometimes after I trick it into going to higher voltage, it reverts back to 90v range. This is annoying because I am only getting ~50% power when I need it the most.

Can anyone “shed some light” on my situation?

View attachment 136344View attachment 136345

what is your panel voltage?

 

[mountkay]

what is your panel voltage?

Open Circuit Voltage - 46.6
Maximum Power Voltage - 37.7

If you hadn’t seen it James, there is another user that reported the same thing:
“The 2P1 inverter's MPPT input "idles" around 285W until I interrupt the input, then it instantly increases to match generation of the 2P2 inverter's MPPT input, around 2kW in this example. The 2P2 inverter has adjusted the panel voltage to around 315V while the 2P1 inverter is running at 90V until I interrupt the input, then it adjusts to a similar voltage, around 320V.”

EG4-6500 losing clock and MPPT issues

system is: two inverters configured split phase, each with 3.4kW of panels connected to PV1. The 2P1 inverter loses about an hour per day on its clock, the 2P2 inverter does not. The 2P1 inverter's MPPT input "idles" around 285W until I interrupt the input, then it instantly increases to match...

diysolarforum.com

EDIT::

I got a video of the issue, showing it quite clearly.

 

[trig2]

Exact same issue with the 6500. Here's the last two mornings. Yesterday it sorted itself out automatically, today I went out and switched the breakers to get it to reset and start producing as it had been stuck for an extended period of time. Nominal OCV for the strings is 424v

Looks like this was supposed to be fixed in the march 3rd firmware update, I updated a week or so ago.

 

[SignatureSolarJames]

firmware version? @trig2 (great name btw)
@Markus_SignatureSolar

 

[JacksonSolar]

Exact same issue with the 6500. Here's the last two mornings. Yesterday it sorted itself out automatically, today I went out and switched the breakers to get it to reset and start producing as it had been stuck for an extended period of time. Nominal OCV for the strings is 424v

Looks like this was supposed to be fixed in the march 3rd firmware update, I updated a week or so ago.

We released new firmware yesterday to fix these problems

 

[Markus_EG4]

Exact same issue with the 6500. Here's the last two mornings. Yesterday it sorted itself out automatically, today I went out and switched the breakers to get it to reset and start producing as it had been stuck for an extended period of time. Nominal OCV for the strings is 424v

Looks like this was supposed to be fixed in the march 3rd firmware update, I updated a week or so ago.

https://eg4electronics.com/downloads/ please download the newest firmware here

 

[trig2]

We released new firmware yesterday to fix these problems

The 5/5 update?

firmware version

79.67 and 61.12 if I'm reading the display correctly.

 

[Markus_EG4]

View attachment 148472
The 5/5 update?

79.67 and 61.12 if I'm reading the display correctly.

79.70

 

[trig2]

Updated to 79.70 a couple days ago. Seems to be the same. Here's this morning. I have noticed clear mornings are the worst, clouds seem to trigger it to sweep so it doesn't get stuck for so long. It did fix itself this morning.

 

[trig2]

Flipped breakers this morning.

 

[Adam De Lay]

Yeah, something still isn't right. Are your panels out in the open so they get good exposure between 0630 and 0730? Have you opened a ticket with SS?

 

[Adam De Lay]

@mountkay are you still experiencing issues?

 

[mbrolin211]

I have the exact same issue too. I have 4 eg4 6500 in Split phase. All 4 are the older model that came with the grounding screw. In morning or cloudy days I have to turn my pv off, then on to get full power. The latest firmware updates were applied over the weekend and still doing the same thing. No change. Yesterday morning, cloudy too, I Inverters were all pulling around 90 Watts from PV. Turned PV switch off, then all and they were all pulling in about 250 watts after that. That is more then double of the watts being loss if I don't manualy turn off and on my PV systems on cloudy days. I have 30 410 Watt Trina Bifacial solar panels. One series string of 8 panels goes to each Inverter except number 4 which has only 6.

 

[Adam De Lay]

@mbrolin211 and @trig2 can you tell me what the manufacture date is on your inverters? Wondering if it's a pattern on the older models?

You can see an example of mine in the attachment.

 

[mountkay]

@mountkay are you still experiencing issues?

I still haven’t updated my firmware, so I do have the same issue but it hasn’t really mattered with the nice weather and long days.

can you tell me what the manufacture date is on your inverters? Wondering if it's a pattern on the older models?

I have an older model (pre Nov 22) (black terminals) and that is the one that works fine. New model (post Nov 22) (grey terminals) is the one with the issues.

It did fix itself this morning

I havnt had any full cloudy days, but I would be happy if it fixed itself before 9am. It was mainly a problem for me in winter where it would be cloudy all day and would never fix itself.

 

[mountkay]

I have noticed clear mornings are the worst, clouds seem to trigger it to sweep

This is interesting. Full clouds for me would never cause it to sweep, but full sun in a clear sky would always make it work correctly. Seems like my string of 7x 340w panels would only ever go to 500-700w at 90v. If it went over that it would correct itself.
I’m not sure how mine have reacted with a few passing clouds. Maybe that would trigger it to sweep for me as well.