UL 1741-SB

[electrofelon]

Go ahead and tell me I've had my head in the sand or have been living under a rock, thats fine - I have only been doing a couple PV systems per year for the last 6 years. So I go to submit the paperwork for this summer's two systems and I find out that both utilities are requiring inverters certified to UL 1741-SB. OK no big deal I think, just half an hour of digging up the appropriate document showing compliance. Well we usually use SMA SB inverters and it turns out they are not compliant. That is annoying, in addition to just plain crazy on SMA's part to not get that certification. What are they thinking? So now I have to select a new inverter for these projects. There are not a lot of choices. Might have to be Solis/Ginlong. I hate to support the Chinese.

 

[jaggedben]

SMA must have a compliant inverter. Or maybe they are scrambling on it? California statewide implementation of UL1741-SB was delayed from April until September (or August? Need to double check). So I'd think most anyone in the US market is going to have a compliant product soon if not already.

 

[jaggedben]

Hopefully they get compliance on the inverters your using, rather than having to replace. Might need to add some kind if comms interface.

 

[electrofelon]

IT appears we are on it now here in NY. Its a PIA to even find the certificate showing this for many inverters. I have a spreadsheet from the NYS DPS listing 1741-SB inverters, but some of them dont show it on the manufacturer spec sheet or web site. More bureaucratic nonsense making me spend hours more at the computer and increasing costs and hassle for everyone. Yeah this throws a total wrench in the works. I liked the SMA inverters and we pretty much standardized all our systems to them which is nice for obvious reasons. We even have 4 in inventory which will now go in the garbage (not literally of course).

Enphase is on it, but we dont find micros cost effective for our ground mounts. Solar edge really annoys me, probably not for the most logical of reasons I admit but I just cant stand them so they are out. Fronius and SMA dropped the ball, so its pretty much Communist re-education camp China options like Ginlong and GoodWe. V annoyed. Should have been a rock star, I could be in the middle of a week long party and cocaine bender right now instead of dealing with this crap.

 

[ggunn]

This is the first I have heard of UL 1741-SB. How does it differ from the old UL 1741 that we know and love?

 

[electrofelon]

This is the first I have heard of UL 1741-SB. How does it differ from the old UL 1741 that we know and love?

Ok well that's good to hear I am apparently not totally clueless . You can Google it, it's a bunch of vague technobabble.

 

[jaggedben]

Well, UL1741-SB is a followup to UL1741-SA.

 

[electrofelon]

So here is an excerpt from The joint utilities newsletter (which I guess is some dumb joint utilities of New York State organization):

"As UL1741- SB certified and IEEE 1547-2018 compliant inverters start
to become available in 2023, the Joint Utilities are working to ensure that they have the
right tools and capabilities in place......"

National grid and NYSEG/RGE required the supplement B certification on system starting January 1st 2023. Clearly these people are smarter than me and I am just too dumb to comprehend the timing here. So angry

 

[pv_n00b]

A good description of -SA and -SB is here https://solarbuildermag.com/inverte...verview-ieee-1547-2018-and-ul-1741-explained/

 

[analog8484]

This is the first I have heard of UL 1741-SB. How does it differ from the old UL 1741 that we know and love?

The biggest difference is the requirement for out-of-band comms (SunSpec) based PV power control even during ride-through events. More control for PoCo's.

 

[310 BLAZE IT]

at RE+ Mid Atlantic all the inverter mfrs are SB compliant. SMA has a UL cert for their new Tripower X that is pending release I am told... hopefully soon so I can apply for interconnection!

There is close to 0 technical literature floating around which is very unfortunate. I found the article above about 4 months ago and was hoping there was more literature available but unfortunately, it seems the industry is treating it like a black box standard. Not helpful when an engineer must design to IEEE 1547-2018 which may include things other than just UL 1741 SB inverters.

 

[electrofelon]

So an update on my end: We ended up going with solis inverters for this summers three systems, and actually they just came in a few days ago. That's kinda the only option at this point for string inverters besides solar edge. There is another communist one called "good-we", but that's it.