Are there any UL 1741 approved inverters below 6kw?

1201 said:

Growatt SPH 10000TL-HU-US 10.0KW Hybrid Inverter | 15000W PV Input| 10000W Output | 120V/240V Split Phase | Compatible with Growatt AXE LV Battery and Lead-acid Battery

Growatt SPH 10000TL-HU-US 10KW hybrid inverter supports split phase output 120/240Vac, configurable battery charging current/voltage based, and AC/Solar/Generator charger priority by touch screen setting. It is compatible with grid voltage or generator power. When AC power is lost it will...

www.self2solar.com

About 1/3 the price of the solark "15k"

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@Will Prowse You need to review these things already, so they sell out. Then we won't hear about them as much from @1201 .

zanydroid said:

I guess it's free to try SBU and see if that's fine.

Unless the POCO said that there is no second warning after the first one, it's going to be :death:

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The problem is that he "got caught". Anything outside of disconnecting the gear is going to raise a red flag if it doesn't meet their requirements. If he disconnects then stealth reconnects later, and is caught accidently re-exporting the ramifications could be considerably higher. Reconnecting and using much less power could be cause for an inspection, too (waiting on that notice myself).

cs1234 said:

@Will Prowse You need to review these things already, so they sell out. Then we won't hear about them as much from @1201 .

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Oh you're gonna hear a lot from me.
You know how @Hedges has been team sma forever, that's going to be me with the growatt.

I would have reviews by now if UPS hadn't somehow lost mine

I completely agree that the 3k inverters are only exporting power in the SUB mode. I tested all of the modes extensively over the past several months while arguing with the EG4 tech people that they had an issue. They wanted to blame it on my installation with every lame possibility you can imagine even though I answered all of their questions and gave them my data. It is only when I pointed them to these forums that I got their attention.

Plympton, you nailed it. I want to fix the issue once and for all so that I am not waiting for that knock on the door.

John Hutch said:

After receiving a call from my utility company about backfeeding the grid with my EG4 3kw inverter that I was running in an off grid mode,

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Not to divert this thread too much, but - how'd you get caught? Your setup is nearly identical to mine - down to the 120v only, batteries, generator, 2.4 kw mounted on garage, except I'm using Bluetti "consumer" gear and everything goes through a transfer switch.

Did you use so little power that something turned off and caused a blip? My baseload is 150-300w, which I'm hoping is high enough to avoid and blips (if it's even possible with my gear).

Re-reading your post, I can't see why you export and I don't (haven't been caught yet).

1201 said:

Oh you're gonna hear a lot from me.
You know how @Hedges has been team sma forever, that's going to be me with the growatt.

I would have reviews by now if UPS hadn't somehow lost mine

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I look forward to your review.

I installed my setup last October and was running SUB mode so that I could utilize solar when it was available, and switch to utility when it was not. If the grid went down, I automatically went to battery power. In the SBU mode, I found that the lights were always flickering and my wife did not like that. Earlier this year, the utility company upgraded to smart meters in our area, and I got a call shortly after they were installed.

My loads on the subpanel were around 300-500 watts average. The only inductive load I had was a refrigerator and the rest were lights, coffee pot,etc. When I looked at my data on Solar Assistant after I was caught, I could occasionally see a negative wattage showing up going back to when the solar was first installed. It did not seem to always follow the loads changing, but it only occurred when the batteries were fully charged and the solar was producing power.

John Hutch said:

... but it only occurred when the batteries were fully charged and the solar was producing power.

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Interesting. My system is in UPS mode where the solar-first-grid-second charges batteries, and those batteries power the transfer panel. I believe it's almost always doing double-conversion (and less efficient because of that). There is a pass-through mode when the batteries are drained - it uses grid until the batteries are 20% and then switches back to battery.

I'm not sure what happens when the batteries are topped. When that happens if fluctuates between 100 and 99% SOC as it occasionally pulls in solar. I'll keep an eye on what happens around then - I think my Emporia has enough resolution to track it. Thanks for the pointers!

John Hutch said:

I looked at the SRNE unit that was suggested, but even though I am sure it is a good unit, it is the same basic unit as the other 3k inverters. I also cannot find a UL 1741 certificate.

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Only a handful of original manufacturers build these low-end AIO’s, principally SRNE and Voltronics, which are then resold as MPP, PowMr, EG4, Midnite, etc. Your EG4 is Voltronics I believe.

Here’s the Intertek/ETL certificate lookup showing the SRNE’s UL 1741 conformance listing, and the mark on my AIO. I believe it also came with a printed certificate but I didn’t hang onto it.

I understand that these are CE mark and ETL tested to comply with UL 1741, but this is not the same as being UL listed and certified by a national testing agency. Utilities in our country require that they have an actual certificate to show this before they will consider them. The companies that make these inverters have to shell out a lot of money for this testing and certification. That is probably the reason that this is not done on the less expensive products from China.

John Hutch said:

but this is not the same as being UL listed and certified by a national testing agency

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Intertek/ETL is one of many Nationally Recognized Testing Laboratories (NRTL’s) able to certify against published standards:

John Hutch said:

I understand that these are CE mark and ETL tested to comply with UL 1741, but this is not the same as being UL listed and certified by a national testing agency. Utilities in our country require that they have an actual certificate to show this before they will consider them. The companies that make these inverters have to shell out a lot of money for this testing and certification. That is probably the reason that this is not done on the less expensive products from China.

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Any of the various NRTL listed marks should be fine. They can't require a specific NRTL do the testing. ETL listed is just as valid as UL listed, as they are both NRTL. If this were not the case, the AHJ's would be granting a monopoly to a particular testing laboratory.

Doing the testing for a product in their lab and saying it meets ul 1741 requirements is not the same as getting UL Listed. If you look at inverters online, you will see that only a few will say that they are UL 1741 listed. This is because the process a recognized lab must use to legally certify a product for approval is much more involved than running a unit through the test.

John Hutch said:

Doing the testing for a product in their lab and saying it meets ul 1741 requirements is not the same as getting UL Listed. If you look at inverters online, you will see that only a few will say that they are UL 1741 listed. This is because the process a recognized lab must use to legally certify a product for approval is much more involved than running a unit through the test.

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Interesting, I was not familiar with those weasel words.

If you ask for a certificate, listing control number, and the unit has the correct NRTL mark on it it should be fine, no?

If they can’t supply it then you can move on.

Moreover if it made it onto CEC list then I think enough due diligence has been done on your part.

Another layer of protection is buying domestically vs off AliExpress. There may be a higher chance in AliExpress to get one lacking the mark, etc, which would require you to go through AliExpress dispute proces

John Hutch said:

Doing the testing for a product in their lab and saying it meets ul 1741 requirements is not the same as getting UL Listed. If you look at inverters online, you will see that only a few will say that they are UL 1741 listed. This is because the process a recognized lab must use to legally certify a product for approval is much more involved than running a unit through the test.

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Is the inverter not ETL listed? ETL and UL are two separate companies, both of which are NRTL's.. they should be functionally equivalent when it comes to a listing. An AHJ can not demand it be UL listed instead of any of the other NRTL's, if they do, they would literally be creating a situation where only one company is allowed out of many. That's the whole point of the NRTL program, otherwise we could just have UL only and not bother with NRTL at all.

In the picture above, the mark on the inverter specifically says ETL LISTED and that it conforms to UL 1741 standard.

Thanks for your input on the UL 1741 standards conformance process. I have been reading over the documents from my utility for their requirements, and they are vague about what they require as proof that the device is certified. It is possible that they might accept the form that SRNE has on their web site, and if anyone has had success with their grid supplier in getting this approved, it would be nice to let others know. At this time, I am still awaiting a response on an application to use a EG4 6000 XP from my provider to see if it is even acceptable.

The SRNE unit has similar specs and looks identical to the other 3k inverters I have seen, including the EG4 that I have used. It is possible that they found a way to lock out the function that causes the backfeed issue, but I am not willing to take a risk buying something else that could put me back in the same place that I am at today.

I decided to submit another application to see if I can get approval for a system using the Solark 5K-1P as the inverter. From all of the information I have been able to find on this forum and other online sources, it really seems to be ideal as a replacement for the 120 volt emergency backup I have built. If they will only approve the 6000 XP, I will rebuild my system as a 240 volt backup. Once I get an approval reply from my utility company, I will order one of these two units. I will post later with their response(s).