EG4 6500EX F08 Error

[kburndred]

Error 08 is encountered when BUS voltage is too high. Error 08 has several different things that cause this error code to appear. There are 3 different BUSes on these units, and each one could be the cause of the problem. You will want to start off by isolating the inputs of the inverter. Battery power is usually the best place to start here, as battery power is necessary for each of our inverters. Power on the inverter with JUST battery power connected, and see if the inverter throws the error 08. If it does, then you will want to check the BUS bar that your batteries are connected to. If your battery capacity exceeds the amp rating of the BUS bar, then this is likely what is causing your Error 08. If you’ve powered it on with battery, and the error did not appear, you will want to try powering it on with grid power and battery. The two main causes of the error 08 are BUS bars and grid power. If you start the inverter with grid power and battery and the inverter throws the error 08, then there are a few steps that you will want to take.

• Check to see if the AC input voltage is within 5v of the AC output.

If the AC input and AC output have more than a 5v difference, this can cause an Error 08.

• Determine if the AC input and AC output are in the same sub panel.

If the input and output are looped (landing in the same subpanel) this can cause and Error 08. If the error 08 does not occur when you power on the inverter with battery and grid power, try adding PV to the mix. If the error 08 occurs once you add PV, you will want to see if the PV is landing in a subpanel with the AC input or output. If DC voltage is encountering AC voltage in a panel, then you can get an error 08.

Ben, I am encountering fault code 08 on my EG4-6000EX only since we added grid power. The inverter has been running fine for a week but now gets Fault 08 after we added grid power. If we determine that this is the cause what is the solution?
I saw grid voltage at 121 displayed on the inverter and the output voltage was displayed at 120. But the fault occurred some time after.
Could we use a UPS to stabilize the grid voltage? Power conditioner?
Thanks

 

[EG4_Jarrett]

Ben, I am encountering fault code 08 on my EG4-6000EX only since we added grid power. The inverter has been running fine for a week but now gets Fault 08 after we added grid power.

Hello!

I may be able to assist you here. I am the Online Support Manager for EG4 and I offer support to anyone that needs it here on the forum.

The F08 is BUS over voltage. Typically, we see this error when AC and DC power are on the same bus, or there is an input/output loop.

Part of the work has already been done here. Troubleshooting steps that I use for this particular error is to remove all forms of power and add them back into the system one at a time, starting with batteries, until the error code populates. Since you have not encountered the error until grid power was added into the system, we know that grid is responsible for the issue.

I saw grid voltage at 121 displayed on the inverter and the output voltage was displayed at 120. But the fault occurred some time after.
Could we use a UPS to stabilize the grid voltage? Power conditioner?

I don't think that this is going to be too high for it to be an issue. 1 or 2 volts is fine. You can try adding in a UPS. I've seen Growatt systems have a similar issue where they are too far from a conditioning facility, and grid voltage was sitting at 128v, and power conditioners helped resolve the issue. Without being there or seeing if your grid power fluctuates at all, I can't really say that those options will or will not work.

Without really knowing how your grid power acts, I don't want to tell you to do one thing OVER the other, but there are somethings that we can look at to see if we can fix the issue.

Do you have any photos that you can share of you input and output wiring? Where is your PV ground at?

 

[kburndred]

The PV frames are not grounded (yet). The PV combiner box has a earth connection which comes from the main panel.
40 amp breaker in main panel supplies grid to inverter.
40 amp breaker in inverter output, then to sub-panel.
sub-panel breakers connect to house loads.
nuetral and ground from sub-panel to main panel.
confirmed N-G bond exists only in main panel.
PS: The inverter ran for a week with no fault codes without grid power connected.
The issue started as soon as we connected grid power.

 

[kburndred]

I have not yet updated the inverter firmware to allow N-G bond to be disabled. (setting 34 enable).
Not sure if this plays into the issue.

 

[EG4_Jarrett]

I have not yet updated the inverter firmware to allow N-G bond to be disabled. (setting 34 enable).
Not sure if this plays into the issue.

That shouldn't cause a problem like this. Bonding isn't an issue with the error 08.

Error 08s occur when the inverter had AC and DC voltage on the same bus, large voltage differentials between AC input and AC output, having AC input and output land in the same panel, and ground loops between AC input and output. I've seen rare occasions when it was just a faulty inverter as well, but those cases are very few. (Definitely not to be ruled out, just need to check everything).

Who did you purchase the inverter from, and how long ago was that?

Can you add some photos of your wiring? AC in panel, AC out panel, how they are connected to the inverter?

The PV frames are not grounded (yet). The PV combiner box has a earth connection which comes from the main panel.

A picture of this would be very helpful as well.

PS: The inverter ran for a week with no fault codes without grid power connected.
The issue started as soon as we connected grid power.

This is what makes me thing ground loop, or DC on an AC ground.

08's are difficult to find, but once you find it, it's usually a really easy fix.

 

[kburndred]

Thanks for the information. I have updated the firmware and set 34 to enabled. The problem seems to have gone away.

 

[EG4_Jarrett]

That's great to hear!

Not what I expected to resolve the issue, but if the error went away, then that's what matters!

Good call on updating the firmware.

If you need anything else, let me know!

 

[Samsonite801]

@BenFromSignatureSolar Could uneven lengths of battery cables cause error 08? My + and - battery cables were previously inconsistent lengths, and I noticed the load numbers on the inverter did not make sense, as well as getting Error 08 when charging the battery from grid power.

I cannot say for certain making the + and - battery cables as close to the same length as possible fixed everything, but I can say that after I made the battery cable length equal, my load numbers have been accurate, and I've received no more Error 08.

No solar panels are connected to my system yet.

FYI, all the positives, from the inverters to bus bar should be the same length, and all positives from bus bar to battery modules need to be the same length, and same rule for negatives from inverters to bus bar and from bus bar to battery modules.

But positive side and negative side lengths to not need to match each other. Only the paralleled lengths in the circuit...

 

[kburndred]

Thanks for the information. Here's how I setup my 2 18KPV battery cables. All cables are matching lengths.

 

[bikerider4818]

Thanks for the information. Here's how I setup my 2 18KPV battery cables. All cables are matching lengths.

What brand bus bars are those? Are they the ones saw on Signature Solar's website which are currently out of stock? I've searched everywhere and I can not find anyone selling anything like them. I even checked AliExpress.

 

[kburndred]

Those are SS busbars.