sunshine_eggo
Happy Breffast!
You can use it in an NEC compliant installation, i.e., 1) completely off grid or as 2) grid backup or 3) off grid with grid backup.
48v Multiplus-II: UL 1741 ?
- Thread starter solar_trees
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You can use it in an NEC compliant installation, i.e., 1) completely off grid or as 2) grid backup or 3) off grid with grid backup.
sunshine_eggo
Happy Breffast!
FWIW, grid tie listing is usually (always?) "UL1741 SA"
sunshine_eggo
Happy Breffast!
Yep, but they don't always respond quickly enough. A large load shutting off can cause momentary feedback before the inverter can adjust.
Uncertain as to whether this would fall under the UL1741 - doubt it.
Assuming you mean AC coupling/frequency shifting, yes. Not sure if this falls under 1741 or 1741SA. I think you could get away with an AC coupled system in a grid down situation.
cs1234
Solar Wizard
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- May 9, 2022
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- 2,302
Can any CT controlled "zero exporting" inverter go fast enough to never momentarily throw some into the grid? It would be nice if it were configurable as to how much it always pulls from the grid in the software, but I imagine that's up to the actual CT and it's particular electrical characteristics.
Yes, I meant AC couple microinverters on it's AC output side. Can it vary their output, or just on/off?
If it can do both of those above things, that makes the UL1741 MultiPlus one of the least expensive UL certified devices capable of doing those things. Strange for Victron to be one of the least expensive options.
So based on what @HighTechLab posted on the cert for the MP II-48v/120, it should pass for inspection for critical load backup and/or grid-tie which is awesome. From a critical load backup perspective, two in split-phase can pass through 240v@50a and supply 80% of 240v@25a under inverter power. Good amount of LF power that is 1741-SA UL certified
zanydroid
Solar Wizard
Very doubtful. Best you can do is have the CTs directly connected, but then there will still be some latency. If you use remote CTs the encode/decode onto the bus will add a ton of latency just by itself.
The base level sampling rate on a smart meter can be quite high -- kilohertz or higher (though note this is rolled up into accumulators etc so the data isn't actually transmitted to POCO at this granularity). And you could always have a rather large load turn off instantaneously, which would likely be able to create a decent size spike of export for that sample point, regardless of how the CT export is implemented. I believe the best the CT export implementation can do is export less over some following period of time to cancel this out on average.
Maybe this will give you some ideas on what you can do with Victron. It has Grid power setpoint where you can give it a goal, I believe you can give it a goal of drawing X W from the grid. There are a few posts on Victron forums about advance configuration of ESS to do fancy things.
ESS mode 2 and 3 [Victron Energy]
www.victronenergy.com
As for the price point. Well, it IS only 2400W / 3000VA size of a unit.
zanydroid
Solar Wizard
Generator that feeds into a Modified Sine Wave stage before outputting power.
Modified Sine Wave (not Pure Sine Wave / PSW).
MSW’s are considered ‘dirty’ 60Hz AC power but most budget generators use this type because they are cheaper.
I’m trying to understand whether the Multiplus II can charge a battery from a ‘dirty’ MSW power source…
The cert says UL1741 Ed.2, to me that means SA (Second Amendment)??? Just making it up but maybe.
Edit. Just found this: https://www.stellavolta.com/blog/what-is-ul-1741-sa/
zanydroid
Solar Wizard
That feels overly optimistic. I found this snippet with a quick Google
By September 28, 2021, UL published UL 1741 Third Edition with substantial updates to Supplement SB that clarified these testing issues. Compliance to IEEE 1547-2018 is now verified by certification to UL 1741 Third Edition using Supplement SB and IEEE 1547.1-2020.
Which suggests to me that the edition refers to the document, and each Supplement is an extra set of chapters in the standard that can be added to the certification.
If you want to waste your weekend you can always read UL1741 for free on UL's website. It's only 258 pages
Another way to see if SA is supported is by looking through the Victron documentation and see if the required grid support functions are configurable. If they are, then that is positive evidence that SA is possible. If not, then you still don't really know. Maybe the documentation is incomplete.
Agree it was more than overly optimistic. Anyway for my use case I can’t sell to grid anyway in my area so will use it for critical load grid backup.
When I looked at the Victron forum I don’t think there is an ESS profile for US. In order to enable certain functions it seems like you need to select “other” for the US. Unsure what “other” actually does.
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zanydroid
Solar Wizard
I'll note that even if we believe that Ed2 <-> SA, this is still not ok to install in California because California will require SB this year (well specifically the IEEE standard embedded in SB, but SB is the a straightforward way to certify to it), probably early April. Ed2 <-> SA implies Ed3 <-> SB
EDIT: IEEE 1547.1-2020
EDIT: IEEE 1547.1-2020
zanydroid
Solar Wizard
Enphases IQ8 cert is very very unambiguous compared to the cert for the MP-II. It specifically says it should be cool for California and Hawaii. On top of explicitly saying SB is covered.
sunshine_eggo
Happy Breffast!
I have a $400 Predator 3850 with sloppy 58-62Hz output. Is it MSW?
My Quattro handles it great. There are additional options, which make it further tolerant of dirty power, but I'm not using them.
Worth a read:
MultiPlus Generator FAQ [Victron Energy]
www.victronenergy.com
solar_trees
New Member
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The UL Certificate for the 48v Multiplus II is on the Victron website now.
agarg
New Member
Pardon my ignorance, but isn't 1741 just short for 1741 SA. For it to be 1741 SB, it needs to specifically stated?
agarg
New Member
I could handle 192 pages easy but 258 is very steep!
Solar Guppy
Red Cobra Guppy
It does need to be specifically stated. UL1741 goes back decades and has many revisions. The NEC 2020 calls out specific revisions, such as the now UL1741-SB requirement
This has a short explanation
zanydroid
Solar Wizard
Wasn't aware that NEC would call out SB, is that in an advisory note? Wondering what the context is for safety.
SA and SB certifications/test suites were designed so that a certificate for SB satisfies the lower levels, and likewise for SA. So it's weird that Victron did not just go for SB and get 1741 covered ?
