EG4 6000ex UPS mode question

[krispykritter]

Hello all! First time poster but I've been lurking for quite a while and have gotten innumerable bits of great information here from all of y'all - very much appreciated.

I have an EG4 6000ex split phase inverter connected to an EG4 Lifepower 5kwh 48v battery and 3.2kw worth of solar panels. I've spliced this into the power feed from my main panel to my basement subpanel, so the the basement runs on battery/solar most of the time, with grid backup if the battery drops low enough (I'll be adding at least one more battery in the near future).

I have a question, however, that I've been unable to find the answer to. Generally, I'd like the run the setup like an UPS for the basement. We do time-of-use metering here, so I'd like to avoid grid usage as much as possible from 1pm to 7pm every day, and if we do lose power, run everything off of the battery until it runs low. The solar generally provides enough wattage to run everything just fine during those hours (in summer at least) with the battery bridging any interruptions in solar generation.

The issue I have is that whenever I put the inverter into UPS mode, it disconnects grid power. The 'grid' indicator starts flashing, and I run on battery, no matter how low it gets.

Is this the expected behavior for this unit? As is almost always the case, the documentation is incredibly unclear about certain effects of the various settings. Trial and error has gotten me far, but I'm hoping to be able to run in UPS mode to avoid power cycling all my internet and network equipment if power goes down.

Thanks for any help!

 

[wildhorsesracing]

I believe that is how mine works as well, it uses the batteries until they reach a certain level and then kicks in the grid power to takeover and recharge the batteries above the 2nd preset level.

 

[Mattb4]

Looking through the manual what is your setting for #1, Sub or SBU?
Setting #2 is the AC input voltage range that mentions UPS which relates to the voltage of incoming AC (grid) .
Settings #20 and 21 control when you switch to grid and when you switch back based on either battery voltage or SOC if you have BMS communication.

There are settings for AC charge time (operating in bypass) and also AC times you do not want to run from PV/battery.

 

[krispykritter]

I believe that is how mine works as well, it uses the batteries until they reach a certain level and then kicks in the grid power to takeover and recharge the batteries above the 2nd preset level.

The problem is that it doesn't seem to ever kick in the grid power. The battery dies, and the inverter switches off the input.

Looking through the manual what is your setting for #1, Sub or SBU?
Setting #2 is the AC input voltage range that mentions UPS which relates to the voltage of incoming AC (grid) .
Settings #20 and 21 control when you switch to grid and when you switch back based on either battery voltage or SOC if you have BMS communication.

There are settings for AC charge time (operating in bypass) and also AC times you do not want to run from PV/battery.

I've tried both SUB and SBU. It's currently set to SUB.

It says in UPS mode it expects 95-140 VAC versus 65-140 for appliance mode. It's own display shows 120v 60hz when in UPS mode but still no dice on using grid power.

I use SolarAssistant to control the battery discharge cycle but messing with those settings still doesn't give me grid connect in UPS mode. Setting 20 is set to 51v (and I cannot set it higher, which is a major issue IMO) and 21 is set to 54v. In appliance mode, this works fine but in UPS mode it does not.

I've not seen my battery drop to 51 volts yet despite being 'dead' (by dead I mean there's an alarm light on the battery itself and zero charge indicators). I've come down to the basement in the morning and everything is off.

Charge time (30/31) is set to 00.0 for both start and stop. I assume that means it can charge anytime, but that's not actually stated anywhere.

 

[Mattb4]

I am not familiar with how the AC bypass time settings are made. So hopefully someone else can advise you. It appears that that might be the problem.

 

[krispykritter]

Digging in the manual some more, I found a something in the general troubleshooting section specifically for this case

"Utility/AC input is available, but the unit only pulls energy from the batteries when in utility/AC input as priority source"

Well, there doesn't seem to be a setting that matches that statement, but it's close to what I want.

The suggested fixes are "Fix AC quality" (AC quality is fine here) or to set output priority as "utility first" which isn't actually an option that can be set.

Oh well, hopefully appliance mode usually doesn't cause a power hit if power is lost to grid. Kinda annoying but probably not a huge deal.

 

[krispykritter]

As an experiment, I set the inverter back to UPS mode last night. This morning, the basement power was off again. I checked all the values that I thought made sense but there were no errors or anything out of whack. AC input voltage was 123v and frequency was 59.9. Battery voltage was 48.8v and completely dead. I was hoping it would kick over to grid when the battery voltage reached 51v in UPS mode but that didn't happen.

Once I got all my screenshots, I changed the mode from UPS to APL and bang, all the power came back on.

The issue appears to be that something is broken when in UPS mode that isn't broken in appliance mode. I've started a conversation with Ben from signature solar on the forums (yesterday) so I'll give that process some time to work out before I get too worked up.

 

[krispykritter]

Alright, now I've got more issues - Error 52 has been thrown at least 3 times in the last 12 hours. The first time, I tried to just turn off/turn back on per the manual but it just immediately did error bp then 52 again. Then I turned off all loads via circuit breakers, cycled the inverter, and it came up. Then I added the loads back in one at a time, and it stayed up and running this time. Once everything was back online, it showed a load power of about 2000 watts pretty even between L1 and L2.

I switched from SUB to SBU and went to sleep.

I woke up at 3 am because it was quite warm in the house, and realized the inverter had gone back into error 52. I cycled everything at 3 am and got it back up, and have left it in SUB mode since.

Even accounting for inrush current, I would think a 5kwh battery at 80% charge would be able to handle loads starting up. I believe it's a 100amp BMS, so max continuous power should be 4800 watts, which is WAY below the max load I've seen on my system (around 3600 watts).

Ben is hooking me up with a troubleshooter today. I'm hoping it's just a faulty inverter because my electronics are getting tired of taking multiple power hits per day.

 

[krispykritter]

Aight, more interestingness. I've been having issues with my USB hubs, particularly the one plugged into an external power supply. I finally got off my lazy butt and took some screenshots of the AC signal coming from the inverter and the power coming out of the DC powersupply to the USB hub. Unfortunately, I have no way to put a 'load' on the DC supply while also checking the output, so keep in mind it's not a 1.5v supply.

Here's what I found:

AC signal at wall outlet by my desk (on inverter power)


Zoomed in a bit more:


All the zooms:


DC supply showing 120hz glitchiness (~8.1ms between nasty bits) (ie matches the nasty on the rising and falling edges of the 60hz signal):



Zoomed way in:



And now I'm out of Electrical Engineering knowledge.

Anyone out there have any idea if any of this is a problem? My USB hub keeps connecting/disconnecting and my water heater has been glitchy ever since I installed this system.

I haven't heard from signature solar yet today, so I'll be calling shortly. Just hoping someone has an idea if this stuff is an issue or if I'm just not that familiar with what AC power should look like.

 

[krispykritter]

I just did the same test with a grid-power only outlet and it shows the same behavior.

So either the inverter is making EVERYTHING behave badly, or it's normal AC quality. I don't actually know which but I can probably turn off the inverter after work this evening and see if the signal looks any different

 

[DIYPV]

Go into the last tab in solar assistant and open inverter settings. Show us picture of battery setting and all other settings below that section.

 

[krispykritter]

 

[DIYPV]

Under Battery Settings change charger source priority to solar and utility to verify that grid charging works. I think your battery is draining because you’re on solar only so changing as mentioned will allow grid charging.

I would change AC input voltage range to UPS. This should not disrupt any other settings.

 

[DIYPV]

Do you have solar assistant graphs of grid/load/solar and SOC when voltage reaches 51V?

In last tab of Solar Assistant, share Inverter model and usb selection and well as battery setting below. Is your battery communicating with solar assistant or are you using emulated values?

 

[krispykritter]

Under Battery Settings change charger source priority to solar and utility to verify that grid charging works. I think your battery is draining because you’re on solar only so changing as mentioned will allow grid charging.

I would change AC input voltage range to UPS. This should not disrupt any other settings.

Grid charging does work; I've verified this. However, it only works in appliance mode. When set to UPS mode, it drains the battery all night and dies around 4-6 am without ever pulling from the grid. As soon as I set UPS mode, the AC input widget starts blinking.

I have it set to solar only as I've only got one battery and not many loads and am way over-paneled at the moment. Once I get it to work properly I'll be adding more loads and hopefully batteries, then we'll see if I need grid charging.

Here's the battery SOC over several days. There's weird stuff in there because solar assistant was disconnected some of the time, or I had switched off the inverter to do some wiring, etc.



Here's where I had the inverter set to UPS mode:

Do you have solar assistant graphs of grid/load/solar and SOC when voltage reaches 51V?

I'm not sure I've figured out how to make custom graphs yet but that would be handy.

 

[DIYPV]

In solar assistant, under second tab the first graph is overview. I want to see when battery hits 51V then drains.

Is battery connected to solar assistant / Pi or are you using emulated values?

 

[krispykritter]

Solar Assistant is connected directly to the battery.

My graphs are all messed up because I've been working on the system this weekend, and the overview graph doesn't show battery info for me:

 

[DIYPV]

Solar Assistant is connected directly to the battery.

My graphs are all messed up because I've been working on the system this weekend, and the overview graph doesn't show battery info for me:
View attachment 156846

can we see this graph for last 2 days?

 

[krispykritter]

yep,

 

[DIYPV]

What’s your battery voltage on 7/9 around 4am? It should be somewhere around 51V.