48v Multiplus-II: UL 1741 ?

[solar_trees]

I just noticed that Current Connected lists a new version of the 48v Multiplus-II 3000VA Inverter as UL 1741 Certified. Is this a mistake or did the 48v Multiplus-II finally get certified? I didn't see any updates about it on Victron's website.

 

[sunshine_eggo]

@HighTechLab ?

 

[ChrisG]

Interesting. Was just thinking about getting a Quattro 5k for a new project and posted in another thread about it. This may change my direction.

 

[zanydroid]

Bumping this thread as I’ve just now found out about this and want to see if you all have found any additional information

 

[ChrisG]

@HighTechLab Are these truly UL1741 Certified? I can't find anything on Victron's site about it.

 

[HighTechLab]

For some reason tags weren't working until just a few days ago..
EDIT: Here is the certificate of conformity to UL1741 standards: https://www.victronenergy.com/uploa...-and-CSA-C22.2-MultiPlus-II-48V-3kVA-120V.pdf

I'm awaiting the final test report and certificate to mark from Victron, but they are on the price list as UL 1741 certified and bear the mark from the testing lab:



In my opinion, until they have the authorization to mark paperwork published, there will be some trouble getting a system permitted...but they told me it's coming soon

 

[ChrisG]

Thank you for the very prompt response @HighTechLab and yes that was my email asking the same question to CurrentConnected sales. Try to figure out which way to go here on a purchase.

 

[zanydroid]

Awesome, thanks for confirming @HighTechLab

Is there a place where I can read up on which parts of UL1741 were tested?

And I assume this is UL1741 and not UL1741SA? What are the implications of UL1741 only? For one I believe it will cause issues with interconnecting with California POCO, but I'm also curious as to what else it would limit, EG AC coupling as the grid forming, and as the grid interacting inverter. My understanding is that Victron supports grid forming, & frequency shifting/sinking power as appropriate when AC coupled.

 

[RCinFLA]

I trust Victron engineering more than any other hybrid inverter.

UL1741 would have no impact on their present AC coupling capability other than adding the allowance for grid export.

From my brief reading of Cal rule 21, the tough part Victron may not address is the power factor correction aspects. Cal rule 21 requires your GT inverter to help improve your house loads power factor. This requires remote current sensors on grid mains input lines to measure total incoming current to voltage phase relationship. Victron does have remote CT capability.

To improve load power factor, any power push by GT inverter has to shift the peak current phase profile of the GT inverter, off the normal in-phase with AC voltage on GT inverters, to help correct your house load power factor seen by grid. This power factor correction assist can also reduce your GT inverter maximum output power capability.

The primary power factor offender for residential use is air conditioning with their single phase induction motor compressors.

A simpler method would be to put a bank of AC run capacitors, with relays, to kick in various amount of capacitance to compensate power factor. This is how Poco power factor corrects on their transmission lines. Not much to do with GT inverters. My guess is some manufacturer will create a stand-alone add on box to do this to make a non-Cal rule 21 compliant GT inverter effectively compliant.

All new smart meters can measure and report power factor, so it is just a matter of time before Poco's start charging extra for residential poor power factor loads.

 

[zanydroid]

Appreciate the writeup.

Is this power factor correction only required for string & storage inverters? I believe my microinverters (Hoymiles HM series) are compliant with 1741SA and i am sure Enphase is too. There are optional CTs for both but it’s not standard to have them.

I think either Rule21 or SA also requires some additional response functions besides frequency shift.

 

[HighTechLab]

Speculation: I think they will cover this when you set the applicable grid-codes in the inverter programming software. The thing is though, they currently don't have a "USA" grid code, for example UL1741SA or UL1741+IEE1547

 

[fafrd]

For some reason tags weren't working until just a few days ago..

I'm awaiting the final test report and certificate to mark from Victron, but they are on the price list as UL 1741 certified and bear the mark from the testing lab:
View attachment 136145
View attachment 136147

In my opinion, until they have the authorization to mark paperwork published, there will be some trouble getting a system permitted...but they told me it's coming soon

Interesting development and I absolutely agree we need to await publication of the paperwork, but in the meantime I have a few quick questions:

1/ does this mean that the 48VDC 120VAC Multiplus II has been tested and is being certified in a way that the 24VDC 120VAC Multiplus II and the 24VDC 120x2VAC Multiplus II have not?

2/ Assuming the answer is ‘yes’, do you know whether Victron has any plans to certify the 24V Multiplus II models for UL1741?

3/ Whether it will be UL1741 certified or not, do you know whether Victron has any plans to introduce a 48VDC 120x2VAC Multiplus II into the US market and if so, when?

 

[fafrd]

I trust Victron engineering more than any other hybrid inverter.

UL1741 would have no impact on their present AC coupling capability other than adding the allowance for grid export.

From my brief reading of Cal rule 21, the tough part Victron may not address is the power factor correction aspects. Cal rule 21 requires your GT inverter to help improve your house loads power factor. This requires remote current sensors on grid mains input lines to measure total incoming current to voltage phase relationship.

Just want to clarify that this requirement applies to ESS only. My Microinverters are Cal Rule 21 compliant but do not have any remote current sensors on grid mains input lines…

Victron does have remote CT capability.

Not sure why you say that. The 120VAC Multiplus II model has an input for a remote CT sensor and comes bundled with one…

To improve load power factor, any power push by GT inverter has to shift the peak current phase profile of the GT inverter, off the normal in-phase with AC voltage on GT inverters, to help correct your house load power factor seen by grid. This power factor correction assist can also reduce your GT inverter maximum output power capability.

Again, interested in how this applies to Microinverters without any CT sensors or other ways to measure mains input I/V phase relationship…

The primary power factor offender for residential use is air conditioning with their single phase induction motor compressors.

Would the same be true for refrigerators and freezers?

A simpler method would be to put a bank of AC run capacitors, with relays, to kick in various amount of capacitance to compensate power factor. This is how Poco power factor corrects on their transmission lines. Not much to do with GT inverters. My guess is some manufacturer will create a stand-alone add on box to do this to make a non-Cal rule 21 compliant GT inverter effectively compliant.

Would such a box require CT sensors on the grid mains and if so, could it be a standalone solution for achieving CA21 compliance or would it need to communicate with the GT inverter?

All new smart meters can measure and report power factor, so it is just a matter of time before Poco's start charging extra for residential poor power factor loads.

At least in California, I believe that would require prior approval by the CPUC and probably at least a 1-year advance warning.

I’m interested to understand whether a stand-alone box with CT sensors on the grid mains (or RS485 communication with an Energy Meter on the Grid Mains) could solve this issue without needing to communicate with the inverters…

 

[HighTechLab]

Interesting development and I absolutely agree we need to await publication of the paperwork, but in the meantime I have a few quick questions:

1/ does this mean that the 48VDC 120VAC Multiplus II has been tested and is being certified in a way that the 24VDC 120VAC Multiplus II and the 24VDC 120x2VAC Multiplus II have not?

2/ Assuming the answer is ‘yes’, do you know whether Victron has any plans to certify the 24V Multiplus II models for UL1741?

3/ Whether it will be UL1741 certified or not, do you know whether Victron has any plans to introduce a 48VDC 120x2VAC Multiplus II into the US market and if so, when?

1. yes.
2. It has not been confirmed or denied...but my sales rep has indicated this is not the direction they are going.
3. Also has not been confirmed or denied, but in my opinion, probably not

I don't work for victron, merely sell it...so don't take my word as fact but rather to the best of my understanding.

 

[fafrd]

1. yes.
2. It has not been confirmed or denied...but my sales rep has indicated this is not the direction they are going.
3. Also has not been confirmed or denied, but in my opinion, probably not

I don't work for victron, merely sell it...so don't take my word as fact but rather to the best of my understanding.

Thanks for the prompt reply.

So it sounds like if you want a Victron Multiplus inverter certified for CA21 and ESS, 48V and 120Vx1 is the only option.

I see ‘larger cabinet’ mentioned on your website - can you summarize the primary differences between the 48VDC 120VAC UL21-certified Multiplus II and the 24VDC 120VAC non-UL21-certified Multiplus II (of provide a pointer of that is already listed elsewhere)?

Aside from the difference in battery voltage and the fact that at 24VDC, you have to option for dual-pole-to-single-pole backup power with a single 120x2VAC Multiplus II model, I’m interested to know what other differences the new CA21-certified 48V model incorporates…

 

[zanydroid]

in my opinion, probably not

Appreciate the detailed reply. Do you have any info on whether UL9540 is being pursued for any systems with Victron inverters?

 

[fafrd]

1. yes.
2. It has not been confirmed or denied...but my sales rep has indicated this is not the direction they are going.
3. Also has not been confirmed or denied, but in my opinion, probably not

I don't work for victron, merely sell it...so don't take my word as fact but rather to the best of my understanding.

By the way, one more quick question:

By ‘not going that direction’ did your sales rep mean that Victron’s strategy for any Multiplus products certified for UL1741 and ESS will be to limit them to 48CDC supply and never introduce UL1741-certified products supplied by 24VDC batteries?

 

[HighTechLab]

By the way, one more quick question:

By ‘not going that direction’ did your sales rep mean that Victron’s strategy for any Multiplus products certified for UL1741 and ESS will be to limit them to 48CDC supply and never introduce UL1741-certified products supplied by 24VDC batteries?

I am going to stop responding in regards to the Victron roadmap because I don't want to speak out of line or have words put into my mouth.

can you summarize the primary differences

Let's compare more similar products - the UL version of this inverter and the non-ul version.
The UL version of this inverter has a bigger wiring compartment and different ventilation holes, and the UL markings. I can't distinguish a single other change.

The differences between a 24v 2x120v and a 48v 1x120v are just as you probably already know - different battery voltage and different output terminals/connections

Do you have any info on whether UL9540 is being pursued for any systems with Victron inverters?

Not that I can publicly release.

 

[fafrd]

I am going to stop responding in regards to the Victron roadmap because I don't want to speak out of line or have words put into my mouth.

Fair enough. I asked Victron directly and will report back on what they say.

Let's compare more similar products - the UL version of this inverter and the non-ul version.
The UL version of this inverter has a bigger wiring compartment and different ventilation holes, and the UL markings. I can't distinguish a single other change.

Just to be certain we are comparing the same models, the new UL-listed Multiplus II PMP482305102 has dimensions of:

21.8 x 10.8 x 8.6

And the non-UL-listed Multiplus II PMP482405100 has identical dimensions. So are you stating that the UL-listed model has a larger onternal internal wiring compartment despite the fact that the outside dimensions are identical? Or are you perhaps comparing to the older non-Multiplus II model (the Multiplus PMP482200100)?

The differences between a 24v 2x120v and a 48v 1x120v are just as you probably already know - different battery voltage and different output terminals/connections


Not that I can publicly release.

Understood.

 

[HighTechLab]

And the non-UL-listed Multiplus II PMP482405100 has identical dimensions. So are you stating that the UL-listed model has a larger onternal internal wiring compartment despite the fact that the outside dimensions are identical? Or are you perhaps comparing to the older non-Multiplus II model (the Multiplus PMP482200100)?

No, those dimensions for the UL model are wrong. It's bigger.

EDIT: