EG4 18kpv Alarm - 'Trip by Vac abnormal' and 'Trip by no AC' - Inverter AC power output turns off

Samsonite801

Solar Wizard
Joined
Oct 15, 2020
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Ok, I have a neighbor who has one of the new 18kpv inverters, with 6 Lifepower4 batteries. All hooked up fine and working great for a couple days so far.

Then today they came over to my lot, and told me the power went off. I go and check it out, find that inverter keeps shutting off the inverter AC output relay the very instant I turn on the internal output breaker, sets the alarms seen in the title here.

For kicks, I test the ohms resistance on the output side property circuit and get about 900Ω which is far from a short, so I go out to all the circuits on the property, turn off all breakers, and the very last thing in the circuit left over was one RV plugged in with another extension cord in between. Turns out, it was the cause. Leave it unplugged and 18kpv is happy.

That RV works fine when the cord is plugged into a generator.

Now, I didn't have time to stay and keep troubleshooting tonight, was going to go back later and turn off all the breakers on that RV and turn them on one by one and try to isolate which circuit is causing the 18kpv to shut off it's AC output. Whatever it is, it is not tripping any breakers in the RV.

So here's my question (doing my homework before I go back over there), I am trying to figure out what those two alarm definitions are on the 18kpv.

'Trip by Vac abnormal'

'Trip by no AC'

The closest reference I could find on Google was from this Lux Power Tek manual, this inverter has the same UI, and lists those messages in the display screenshots, but in troubleshooting section it does not give descriptions about what those trips are or what causes them.


Perhaps someone else knows, or could help me find out what are the conditions or thresholds that trip these alarms?
 
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Ok, I have a neighbor who has one of the new 18kpv inverters, with 6 Lifepower4 batteries. All hooked up fine and working great for a couple days so far.

Then today they came over to my lot, and told me the power went off. I go and check it out, find that inverter keeps shutting off the inverter AC output relay the very instant I turn on the internal output breaker, sets the alarms seen in the title here.

For kicks, I test the ohms resistance on the output side property circuit and get about 900Ω which is far from a short, so I go out to all the circuits on the property, turn off all breakers, and the very last thing in the circuit left over was one RV plugged in with another extension cord in between. Turns out, it was the cause. Leave it unplugged and 18kpv is happy.

That RV works fine when the cord is plugged into a generator.

Now, I didn't have time to stay and keep troubleshooting tonight, was going to go back later and turn off all the breakers on that RV and turn them on one by one and try to isolate which circuit is causing the 18kpv to shut off it's AC output. Whatever it is, it is not tripping any breakers in the RV.

So here's my question (doing my homework before I go back over there), I am trying to figure out what those two alarm definitions are on the 18kpv.

'Trip by Vac abnormal'

'Trip by no AC'

The closest reference I could find on Google was from this Lux Power Tek manual, this inverter has the same UI, and lists those messages in the display screenshots, but in troubleshooting section it does not give descriptions about what those trips are or what causes them.


Perhaps someone else knows, or could help me find out what are the conditions or thresholds that trip these alarms?
Any chance the wiring is bad in or going to the RV? Does the RV have solar or inverter?
 
Any chance the wiring is bad in or going to the RV? Does the RV have solar or inverter?

Yeah, I haven't had a chance to make it back there yet and actually look into the RV itself in more detail. It is just a stock run-of-the-mill RV trailer, with a standard 50a cord feeding an AC breaker box (half the panel for L1 120v loads, half the panel for other L2 120v loads), no 240v usage, an AC to DC converter/battery charger, that's it.

I did briefly look at the RV the other day for unrelated issue, breaker box, and converter, since the charger is not charging the batteries right now. They had too many personal items in the front compartment, so I was not able to get in there and look at the converter itself. That night I had looked at that, it was running on a generator at the time. It was before they moved the cord from the gen over to the 18kpv outdoor plug on the post.

I was just curious what those errors meant. I did not install the inverter. They had another shareholder along with an electrician guy install and wire it all in, but had been originally having trouble getting battery comms to work, so they had called me over to help get that going, which I did (DIP switches weren't set proper on the Lifepower4's, they already did the battery shelf firmware updates before I got there).

Then later, they called me over to look at this new inverter tripping issue, since the electrician was not there, and they didn't have a voltmeter to check on things, so I went over and we narrowed it down to the RV causing the inverter shutdown, so for that night we just unplugged it, since it was still raining.
 
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Those sound like early firmware problems, but I would definitely double check the RV to make sure nothing nasty is going on in there too
 
Those sound like early firmware problems, but I would definitely double check the RV to make sure nothing nasty is going on in there too

I forgot to ask the guy who put them in if they also did the inverter firmware, he did do the battery shelf firmware with SS Support on the phone, in effort to get the battery <> inverter comms working but they forgot to check all the DIP switch settings before I got there.

I'll check the inverter firmware when I go back, thanks for reminding about baseline firmware check.
 
'Trip by no AC'
Firmware would be my first guess here, do they have the monitoring software installed? I can log in and do the update for them.

I would definitely double check the RV to make sure nothing nasty is going on in there too
Depending on how old the RV is or who did the electrical work on it, this could be the case as well.

I've seen a lot of really suspect wiring and shortcuts in RVs. Not saying that this person has done this, but unless it's never had a previous owner, you never know.
'Trip by no AC'
Make sure Run without Grid has been enabled. Just to double check. It could be firmware, but I'm not sure what version they're on.
 
Firmware would be my first guess here, do they have the monitoring software installed? I can log in and do the update for them.

They haven't got that far yet, I'll have to check if their Starlink WiFi signal can reach into that storage container where the inverter is. For now I guess we can look into the offline firmware upgrade option (I'll watch that video now)...


Depending on how old the RV is or who did the electrical work on it, this could be the case as well.

I've seen a lot of really suspect wiring and shortcuts in RVs. Not saying that this person has done this, but unless it's never had a previous owner, you never know.

Yeah, I am trying to imagine what sort of a wiring issue on the RV could cause this kind of a tripping issue (perhaps a GFCI circuit, or something to do with grounding or possible N-G bonding?), again why I was wondering what the error trip messages actually mean (since I'm not seeing a short there).

Perhaps you could maybe reach out to the manufacturer through your potential proprietary channels and see if they could say what those trip errors translate to, like what thresholds are crossed to cause the alarm states to trip?


Make sure Run without Grid has been enabled. Just to double check. It could be firmware, but I'm not sure what version they're on.

I do remember this setting for 'Run Without Grid', was not enabled (their Gen and Grid inputs have never been connected to anything before, and the inverter has been working fine for a few days before the RV was introduced into the mix), but I did also notice the 'Off-Grid Output' was enabled.

When I first got there the first time ever, to troubleshoot the battery comms issue, the first thing I had noticed was off, was the AC output was set to 50 Hz (which I changed to 60 Hz). You'd think it ought to have default of 60 Hz set at factory beings as it was sold in USA market, but it didn't.

The other red flag I noticed when I looked at it last night, was there is no ground rod (circuit) yet on their inverter installation, so I told them to get one (or two) of those installed ASAP. They do have it mounted on a storage container wall, which is steel, and the storage container is sitting on the ground (or maybe some concrete blocks or something).

I saw another shareholder here with a SolArk once who didn't have a ground rod, and he kept having issues with a GFCI outlet tripping the SolArk inverter until I had him add in his ground rod and ground it to the inverter.


Thanks Jarrett for looking into this whole thing some more, I appreciate your willingness to help. I will go over and check out the RV circuits some more, have them install the ground rod, and see to it that the firmware gets firmware updated.
 
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This is a classic sign they are running original firmware and just unboxed it and stuck it on the wall with no settings changed whatsoever.

Yeah true, but so many people (and even many common residential electricians without any solar-system-based installs under their belt) don't yet know enough about inverters or even general solar implementation at this point, to really know what they should start tinkering with, might be afraid to change stuff, and honestly, me being an old ex-drag racer back in the day, it was always wise words to only make one change at a time, and understand the impacts of the change prior to moving on to the next change, so that undoing a mistake doesn't become spaghetti to figure out the cause of a new problem.

I'd prefer they leave it default by the time I get there, so I know what has been done to it (unless each change has been documented), then I can start really messing it all up myself and take full responsibility...

I'm wondering if that alarm for 'Trip by no AC' is related to the 'Run Without Grid' setting not being enabled, but also wondering why it works at all without ever having a grid or generator on the inputs (since that setting has never been enabled). Oh well, wonder away, I'll try setting that too.

Still the 'Trip by Vac abnormal' alarm, would be nice to have even a phrase to explain what they really mean by that, and what causes it to trigger would be an informative bonus.
 
I can 100% assure you that upgrading the firmware is the first thing you must do before you start doing anything else at all. The factory shipped firmware was not what it should have been and this affects its operation as well as some of the factory default settings.
Your "run without grid" being one of them
 
Yeah true, but so many people (and even many common residential electricians without any solar-system-based installs under their belt) don't yet know enough about inverters or even general solar implementation at this point, to really know what they should start tinkering with, might be afraid to change stuff, and honestly, me being an old ex-drag racer back in the day, it was always wise words to only make one change at a time, and understand the impacts of the change prior to moving on to the next change, so that undoing a mistake doesn't become spaghetti to figure out the cause of a new problem.

I'd prefer they leave it default by the time I get there, so I know what has been done to it (unless each change has been documented), then I can start really messing it all up myself and take full responsibility...

I'm wondering if that alarm for 'Trip by no AC' is related to the 'Run Without Grid' setting not being enabled, but also wondering why it works at all without ever having a grid or generator on the inputs (since that setting has never been enabled). Oh well, wonder away, I'll try setting that too.

Still the 'Trip by Vac abnormal' alarm, would be nice to have even a phrase to explain what they really mean by that, and what causes it to trigger would be an informative bonus.
I'd say there is something in the RV dumping electricity where it should not be, possibly to Neutral. I would guess either something changed or was turned on. Vac abnormal means the inverter detected something unexpected on the AC outputs. Is the RV taking a 240V input with Neutral and ground via an L14-50 or something? If it was working and now is not, I would guess rain or some other influence on the RV has created a ground fault condition. If there is no proper ground for the inverter I'd start there, then make sure there is an N-G bond back at the inverter. Then push forward from there and make sure all 4 conductors are valid to the RV plug.

If the RV is 110v you may have pushed the inverter too far out on one leg trying to kick on an electric appliance or something. I would get two amp-clamps or other monitoring for each of the AC legs if you suspect something like this.
 
Hey I just heard another clue I didn't hear the other day when I had been there looking at the inverter tripping problem. I saw the lady (lot owner) at the welcome center tonight, and she said since I had been there the earlier time when the other lady's RV was parked in the original spot (where I had it running on the generator power directly), well she said the other lady, when they and the helpers moved the RV over to the new position by the new outdoor RV plugin, while it had a flat tire they didn't notice right away, and it kind of high-centered on something and she said it tore a bunch of wires out from underneath and there were wires hanging down when they got it to the new spot. Hmmm, something else to wonder about...

Got to thinking about it too, in my troubleshooting when I had checked the resistance across the L1 and L2 and got 900 Ω, I didn't also check L1 to N or L2 to N resistance, in which that leaves out all the RV circuits (which are only either hot to neutral) from my original check (doh), so it could have a short where I didn't see the indication.

I still haven't had the time to make it back over there to look at it and probably won't get back over there until after the holidays since I have a lot on my plate right now. She did say the 18kpv still runs fine without that RV plugged into it. She also said they got the mini-splits installed today on the mobile homes and they work good on the 18kpv fine. She's gonna go get ground rods at Home Depot soon and we'll get that and those other items like firmware and settings all dialed in.
 
I see and hear this so much when someone is trying to describe what is wrong and they are either trying to cover up what they actually broke themselves or give you a long-winded story with no actual evidence.
 
Ok, so I did make it back over there, I got the inverter connected to the WiFi router, having internet now (all 3 LEDs illuminated on WiFi dongle), enabled the web (cloud) UI access, got the firmware updated.

After update, was still getting the Yellow (amber) alert / alarm light and in the Alarm page it was showing the 'Trip by no AC' as yellow. I even rebooted the inverter, and amber alarm still present, but inverter is operational, not actually tripping the inverter, just seems like an amber warning alert.

So I went into the Advanced page and enabled the option for 'Run without Grid', clicked on 'Set', then I got a little warning banner in the upper right corner of screen saying, Are you sure you want to disable grid input? Please make sure no generator is connected to the input.

(may not be exact words, going off memory on exact dialogue message)

So this lady DOES want to hook up a big Generac propane generator to the input (coming very soon), so once that is going, I will need to disable this setting for 'Run without grid' then, based on the warning banner I saw.

Of course, since I set this setting to run without grid, the amber warning alarm and 'trip by no ac' immediately cleared out.

So I am still just wondering what all this means, because once we hook up a generator, I will have to revert this setting, and will the 'trip by no AC' alarm just fire again, and it be expected to see an amber light always on on the front panel?

I wish the manual would have more detail about these settings seen in the Advanced pages. Hopefully SS will work with manufacturer to improve the documentation to some reasonable standards. There is not even enough info for a seasoned (supposed) tech-savy installer to resolve some of these loose ends (other than to figure out behaviors after doing many installs of the same unit and learning the expected behaviors based on the reality of observation, trial and error).
 
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Ok, so I did make it back over there, I got the inverter connected to the WiFi router, having internet now (all 3 LEDs illuminated on WiFi dongle), enabled the web (cloud) UI access, got the firmware updated.

After update, was still getting the Yellow (amber) alert / alarm light and in the Alarm page it was showing the 'Trip by no AC' as yellow. I even rebooted the inverter, and amber alarm still present, but inverter is operational, not actually tripping the inverter, just seems like an amber warning alert.

So I went into the Advanced page and enabled the option for 'Run without Grid', clicked on 'Set', then I got a little warning banner in the upper right corner of screen saying, Are you sure you want to disable grid input? Please make sure no generator is connected to the input.

(may not be exact words, going off memory on exact dialogue message)

So this lady DOES want to hook up a big Generac propane generator to the input (coming very soon), so once that is going, I will need to disable this setting for 'Run without grid' then, based on the warning banner I saw.

Of course, since I set this setting to run without grid, the amber warning alarm and 'trip by no ac' immediately cleared out.

So I am still just wondering what all this means, because once we hook up a generator, I will have to revert this setting, and will the 'trip by no AC' alarm just fire again, and it be expected to see an amber light always on on the front panel?

I wish the manual would have more detail about these settings seen in the Advanced pages. Hopefully SS will work with manufacturer to improve the documentation to some reasonable standards. There is not even enough info for a seasoned (supposed) tech-savy installer to resolve some of these loose ends (other than to figure out behaviors after doing many installs of the same unit and learning the expected behaviors based on the reality of observation, trial and error).
I always run with that option checked. "Run without grid"
 
Me too and it still uses the grid if told too, so I'm not sure what that setting is actually for.
 
It's a generic warning when changing settings on that screen.

It's more a matter that the warning is actually illuminated, and amber warning light is on, also amber is lit on that screen on the alarms page, until I enable 'Run without AC'..
 
Me too and it still uses the grid if told too, so I'm not sure what that setting is actually for.

So you have a generator or grid on your input, and it still works when that setting for 'Run without AC' is enabled? Just wondering why I saw the warning that said make sure no generator is connected popped up right when I clicked 'Set' to enable that option.
 
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