Brand new EG4 6000XP randomly shutting down throwing "W028 EPS overload code"

[Roedel]

I just installed my new EG4 6000XP inverter connected to 2 used Tesla model S battery modules and about 5KW of Solar panels.
Have been able to connect the inverter to the new JK BMS, charging algorithm works flawless as far as i can tell. ( Battery Model 2 in inverter settings)
The inverter is NOT connected to the grid.
Inverter randomly goes into aforementioned error mode, W028, shuts down for 5 minutes and then boots up again.

This happens at any given load, did it twice during the evening with only 200Watts of load, just when the sun was setting. Once the sun set and it is on battery it runs happily all night and also handles high loads without problem.

I also use the inverter to charge our Tesla during prime solar hours, also here the inverter shuts down randomly at different Ampere settings, it happens most often around 12 Amps with full sun available (around 4KW), yes i am using both legs for this, 240Volt AC.

I am unable to identify any pattern other than its always happening when the Mppt is producing Solar energy and the battery is in the Zone of Zero load, shifting between charge and discharge currents.

In order to isolate the problem i disconnected the BMS and switched the inverter to lead acid Battery, problem remains.
I also removed all other loads from the inverter other than the Tesla, it still happens.
Same with car charger disconnected and only the house running.
The inverter and Breaker panels are properly grounded/bonded, installed in a 40' container.

I contacted EG for and Solar Pro guys for advice but got no response so far.
Posted this here to see if anybody else faced the same issue.

 

[Roedel]

i think i found the problem. The inverter seems not work properly with 12S lithium Batteries like the 2x6S configuration from the Tesla Model S i used.
I noticed that the Inverter often shut down when the Battery was nearly full at around 51Volts, even though it would accept that Voltage in the charge settings. This happened with the inverter communicating with the BMS as well as the BMS completely disconnected and the Inverter fully in control of the charge process.
What made me curious was the fact that i could not set a discharge Voltage lower than 40 Volts, even though the Manual states a possible battery Voltage of 38.4-60VDC, Nominal 48 Volts.
That should have put my 12S battery well within the ballpark with 36-49.8 Volt, even though i could not use its full capacity due to the 38.4 Volt limit (the 12S would be at 36Volts when discharged to 3Volts each cell).

Out of desperation, i never received a reply from 4G or Solar Pro guys, i added another 2 cell bricks from yet another Tesla Model S module i had laying around, turning the Battery into a 14S, thus putting it into the voltage range of 42-58.1 Volts (3-4.15 per cell x 14).
That was more than a week ago and the Inverter never shut down again.
Moral of the Story, Eg4s manual suck (you are on your own), so does the customer service with these products. I have wasted so much time with this problem it is not funny.
Why would the inverter throw a totally unrelated error code to begin with, "EPS overload" while the real problem is some strange conflict between the battery state of charge and the Inverters hard coded charging algorithm ?
Why cant the manufacturer clearly state the Battery configuration it Programmed into the machine in its manual: 14S for Lithium, 16S for LifePo4 and god knows what for lead acid?
Anyway, hope somebody else finds this post useful one day.

 

[EG4_Jared]

I'm glad to see this is now working for you, and I apologize for the delayed response! I will suggest that our Technical Writing team reviews our manual concerning this matter.

 

[Gruic]

i think i found the problem. The inverter seems not work properly with 12S lithium Batteries like the 2x6S configuration from the Tesla Model S i used.
I noticed that the Inverter often shut down when the Battery was nearly full at around 51Volts, even though it would accept that Voltage in the charge settings. This happened with the inverter communicating with the BMS as well as the BMS completely disconnected and the Inverter fully in control of the charge process.
What made me curious was the fact that i could not set a discharge Voltage lower than 40 Volts, even though the Manual states a possible battery Voltage of 38.4-60VDC, Nominal 48 Volts.
That should have put my 12S battery well within the ballpark with 36-49.8 Volt, even though i could not use its full capacity due to the 38.4 Volt limit (the 12S would be at 36Volts when discharged to 3Volts each cell).

Out of desperation, i never received a reply from 4G or Solar Pro guys, i added another 2 cell bricks from yet another Tesla Model S module i had laying around, turning the Battery into a 14S, thus putting it into the voltage range of 42-58.1 Volts (3-4.15 per cell x 14).
That was more than a week ago and the Inverter never shut down again.
Moral of the Story, Eg4s manual suck (you are on your own), so does the customer service with these products. I have wasted so much time with this problem it is not funny.
Why would the inverter throw a totally unrelated error code to begin with, "EPS overload" while the real problem is some strange conflict between the battery state of charge and the Inverters hard coded charging algorithm ?
Why cant the manufacturer clearly state the Battery configuration it Programmed into the machine in its manual: 14S for Lithium, 16S for LifePo4 and god knows what for lead acid?
Anyway, hope somebody else finds this post useful one day.

Totally agree with the EG4 manuals being terrible. They don't provide any context on how and when to use a specific setting. Here is something worth noting: EG4 doesn't make their own gear. They're more of an integrator of various other people's products. The EG4 6000XP really a rebranded LUX brand inverter. The only difference between the EG4 model and the LUX model is the firmware. EG4 writes custom firmware for all these devices to ensure interoperability with their battery BMS systems. So it might be worth getting the manual for a LUX branded 6000XP and see what's different. I recently bought this same inverter and have had a lot of "W028: EPS Over load" errors without actually having an overload, maybe one every other day. It will overload if you put a strenuous load on it, even if you are under the 4k limit and it will also log the W028 error. After the error, the unit started charging from grid, despite the batteries being in a good state. That kind of surprised me, I didn't expect that.

I do expect firmware updates for this unit in the future, so keep your eyes and ears open for when they're released.

The one good thing I do like about EG4 is that they are here in the US and so far they've stood behind their warranties. Their tech support is hit or miss, but I think they realize this and are working to improve positive outcomes.

When I expand my system, I've already decided my next inverter will be an EMP proof Sol-Ark 18k. Does anyone have any experience with their tech support?

 

[Roedel]

Totally agree with the EG4 manuals being terrible. They don't provide any context on how and when to use a specific setting. Here is something worth noting: EG4 doesn't make their own gear. They're more of an integrator of various other people's products. The EG4 6000XP really a rebranded LUX brand inverter. The only difference between the EG4 model and the LUX model is the firmware. EG4 writes custom firmware for all these devices to ensure interoperability with their battery BMS systems. So it might be worth getting the manual for a LUX branded 6000XP and see what's different. I recently bought this same inverter and have had a lot of "W028: EPS Over load" errors without actually having an overload, maybe one every other day. It will overload if you put a strenuous load on it, even if you are under the 4k limit and it will also log the W028 error. After the error, the unit started charging from grid, despite the batteries being in a good state. That kind of surprised me, I didn't expect that.

I do expect firmware updates for this unit in the future, so keep your eyes and ears open for when they're released.

The one good thing I do like about EG4 is that they are here in the US and so far they've stood behind their warranties. Their tech support is hit or miss, but I think they realize this and are working to improve positive outcomes.

When I expand my system, I've already decided my next inverter will be an EMP proof Sol-Ark 18k. Does anyone have any experience with their tech support?

the Lux manual is a bit better but not much, https://luxpowertek.com/wp-content/uploads/2023/08/SNA-US-6000-User-Manual.pdf

 

[pcfriend]

I ran into this issue with overload being triggered, make sure your discharge current is set to 140.