When do I need a transformer?

[Lt.Dan]

According to the email I got from Ian at Watts247, those LV6548s that you have are the only UL listed ones they carry. Have they been pretty solid for you? What is your setup? Do you have a diagram, or can you just explain?

They are not UL Listed, but they are UL Compliant. Big difference, but still very good.

Very basic explanation, I have 2x wire for split phase in my RV that I live in Full Time. The outputs are wired directly to my power distribution panel, and I have it set to run on Solar/Battery as first priority, amd when the battery gets to 10%, it will automatically switch over to the Grid until the battery is back up to 20%. Check my sig for "The Meg Build", where there is a very in depth install and setup of it all.

 

[daryl_egen]

See. I don't know the difference between listed and compliant. That's part of my issue. Because I want to build my own system at my residence, but I don't know what listings or certifications are required for each component. Being confident that I can build something and building something that is in compliance with my city's code are two different things. It's kind of frustrating. Thanks for the reply.

 

[Lt.Dan]

Listed means UL recognizes it and adds the inverter to their list of approved inverters. Compliant means a 3rd party approves it and says it meets all of ULs requirements, but UL hasn't added it to their list themselves.

 

[daryl_egen]

I guess all I can do is put a plan together and see what the code compliance office says... I really kinda like Growatt inverters and the eg4-LL batteries (and that they can communicated) but then none of Growatt's are UL listed yet and I'm not sure if batteries need to meet certain code criteria... I suppose that's why I'm here... to learn...

 

[Tecnodave]

Here in the USA the NEC (National Electrical Code) states that ALL devices connected to the electricity of a structure MUST be listed to UL by a NRTL (National Reliability Testing Laboritory) which is in the NRTL program operated by the U.S. OSHA (Occupational Safety Hazards Agency)

There is no differentiation between grid tie and off grid. The requirement is for all electricity used in any building which falls under the building code to have all components be listed for the specific applications.

It is not relevant that some other testing agency tests some hardware to be “compliant with the U.L.“ The wording is
“Listed to UL (relevant standard) by an NRTL”

Fred’s garage might be able to test to UL standards but if they are not accepted by U.S. OSHA’s NRTL program it does not mean squat.......

Go look at some major players in the market......for instance my Midnight Classic 150 is “Listed to UL 1741 by ETL”
The Outback Radian Inverter is “Listed to UL 1741 SA by ETL” grid tie/hybird off grid)
The MagnaSine MS4024AE inverter/charger is “Listed to UL 1741 by ETL” (off grid)

ETL (Electrical Testing Laboratories) is an accepted NRTL as listed by OSHA

There are many others such as European T.U.V. is a US OSHA NRTL and as such can and does test and list european gear to U.L.

Do make sure that the testing agency is a US OSHA NRTL for any system used here in the USA and most other countries do have their own standards as to the testing requirements for devices. Canada for instance does have a very similar program for testing verifications, as does Great Britain and Germany

I have seen numerous instances in my local jurisdictions where building inspectors have “Red Tagged“ homes where there are non UL listed components in the electrical systems. (Requiring the power company to remove power from said building, AND remove “occupancy permit”)

Here in California all building inspectors must verify that all solar components are listed with the California Public Utilities Commission. If your inverter, charger, or solar panels are not on the state approved devices list you will not get a “OK TO CONNECT” issued to the local utility issued by the local inspector

I have a pile of offshore gear that I have been paid to remove from buildings to satisfy the local code enforcement department to clear the red tag and permit building occupancy, including the “Fution” AKA Best Sun Powerwall which I was paid to remove from a home in Scotts Valley California (my intervention on this case prevented it from going to the insurance companies and the building department).

Read , trust, but absolutely verify before you throw monies down that rabbit hole.....

Additionally most all insurance policies do require full NEC code compliance

 

[SolarPrep]

Here in the USA the NEC (National Electrical Code) states that ALL devices connected to the electricity of a structure MUST be listed to UL by a NRTL (National Reliability Testing Laboritory) which is in the NRTL program operated by the U.S. OSHA (Occupational Safety Hazards Agency)

There is no differentiation between grid tie and off grid. The requirement is for all electricity used in any building which falls under the building code to have all components be listed for the specific applications.

It is not relevant that some other testing agency tests some hardware to be “compliant with the U.L.“ The wording is
“Listed to UL (relevant standard) by an NRTL”

Fred’s garage might be able to test to UL standards but if they are not accepted by U.S. OSHA’s NRTL program it does not mean squat.......

Go look at some major players in the market......for instance my Midnight Classic 150 is “Listed to UL 1741 by ETL”
The Outback Radian Inverter is “Listed to UL 1741 SA by ETL” grid tie/hybird off grid)
The MagnaSine MS4024AE inverter/charger is “Listed to UL 1741 by ETL” (off grid)

ETL (Electrical Testing Laboratories) is an accepted NRTL as listed by OSHA

There are many others such as European T.U.V. is a US OSHA NRTL and as such can and does test and list european gear to U.L.

Do make sure that the testing agency is a US OSHA NRTL for any system used here in the USA and most other countries do have their own standards as to the testing requirements for devices. Canada for instance does have a very similar program for testing verifications, as does Great Britain and Germany

I have seen numerous instances in my local jurisdictions where building inspectors have “Red Tagged“ homes where there are non UL listed components in the electrical systems. (Requiring the power company to remove power from said building, AND remove “occupancy permit”)

Here in California all building inspectors must verify that all solar components are listed with the California Public Utilities Commission. If your inverter, charger, or solar panels are not on the state approved devices list you will not get a “OK TO CONNECT” issued to the local utility issued by the local inspector

I have a pile of offshore gear that I have been paid to remove from buildings to satisfy the local code enforcement department to clear the red tag and permit building occupancy, including the “Fution” AKA Best Sun Powerwall which I was paid to remove from a home in Scotts Valley California (my intervention on this case prevented it from going to the insurance companies and the building department).

Read , trust, but absolutely verify before you throw monies down that rabbit hole.....

Additionally most all insurance policies do require full NEC code complianc

 

[SolarPrep]

Oops. hit the wrong key.

TechnoDave: I've been trying to make that same point, but you did a great job. I would add that the 2020 NEC added clarification to this section of the code regarding NRTL's. There are lists of currently approved ones, and ones that have lost their approvals also listed on the OSHA site.

There is (and was prior) language regarding local decisions and the role of the AHJ (authority having jurisdiction) but the newly adopted code makes it much easier for them to just point to that statement, and demand proof that the product meets approvals. In our area, you have to submit the entire plan before you begin, and they check it before granting any permit. Then they check to make sure everything is installed according to the plan.

I'm really tired of contacting companies that claim they are "Listed", and people who also make these claims with no proof to back up those claims. Often, it turns out to be some "self certification" stamp of approval. Yeah.....

The only thing in your statement that I MIGHT take exception to is the last sentence. Insurance companies have no means by which to determine "full compliance". There are many things that are grandfathered, there are jurisdictions that don't enforce the latest codes, and there is language that allows localities to make exceptions. I'm not saying that they cannot make a determination that you were not compliant, but rather that you might need to go to battle with them if something happened.

In general, it is prudent to make sure things are actually approved, and take out permits. Get the stuff inspected.