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Victron Quattro + Autotransformer for split phase (which option is best?)

ssean

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Aug 1, 2020
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Greetings,

I'd like to use a Quattro Inverter + 100A Autotransformer to supply split phase power to my home. I'm located in Puerto Rico.

My local installer recommended the following setup:

-10kVA 120V Quattro Inverter (QUA483100100 )

-100A Autotransformer (ITR000100101)

AT-3-split-phase-120V-to-120-240V-with-Quattro-120V


----

After looking at the schematics, this appear to be a better option. Am I missing something?

-15kVA 230V Quattro Inverter (QUA483150000 )

-100A Autotransformer (ITR000100101)

AT-1-split-phase-240V-to-120-240V-with-Quattro-240V


Thanks in advance,
Sean
 
The 230V units appear to give you more bang for your buck.

10kVA 120V - QUA483100100 - $3904.05

10kVA 230V - QUA481030010 - $3709.40
15kVA 230V - QUA483150000 - $4872.20
 
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10kVA 120V = 3904.05/10000= $0.39/kVA
10kVA 230V = $0.37/kVA
15kVA 230V = $0.32/kVA

The 15kVA unit supplies 50% more power and is 13.5% cheaper per kVA, so it wins the "bang for your buck" decisively.

The installer is likely recommending the bigger unit because he doesn't want you pissed off when you don't have enough power. :)

If the choice is between the 230/120V 10kVA units, then the 230V appears to be the slightly better value.

Also note that sometimes Victron's documentation doesn't match their features. The datasheet for the 230VAC unit shows only 50Hz operations, not 60Hz required for typical 120V/240V split phase power systems, so they may not actually be an option.
 
Thanks for the quick reply.

The installer is recommending the smaller unit - 10kVA 120V. I think that's because he has that model in-stock, and the 230V would have to be special ordered.

Looking at the Victron's documentation, it shows the following:

AC inputs (2x) Input voltage range: 187-265 VAC Input frequency: 45 – 65 Hz Power factor: 1

The following website states:

"All Victron VE Bus Inverters, Multi Plus Inverter Chargers and Quattros are available in 230 volt 50 Hz and with a simple software tweak can be converted over to 240 Volt 60 Hz."

 
Sorry. I misread the original post.

The wide input range is to account for crappy grid/generator input.

I would confirm that with Victron before committing to it, but if so, I'd go with the 15kVA option.
 
The 15k unit is for European electricity, 230V 50Hz. Don't over complicate the system, get one designed to be used in PR.

What are your loads that you need 10kW or more? Most of our PR customers are quite happy with a Schneider XW6048 or SW4048, or an Outback Radian GS4048 or 8048. All of these offer 120/240 60Hz without a transformer.
 
What are your loads that you need 10kW or more? Most of our PR customers are quite happy with a Schneider XW6048 or SW4048, or an Outback Radian GS4048 or 8048. All of these offer 120/240 60Hz without a transformer.

I have a multi-unit property. The main house and two apartments.
 
Why can you not just get an inverter that is wired for 120/240V split phase?
I understand if you already have 120v onsite, but if you are contemplating using a 230v auto transformer, you likely do not have the inverter yet.
 
It’s common practice to use the 230v European models and configure them for 240v 60hz and put and AT on the output for split phase and/or balancing the 120v loads. Victron supports this configuration. The only reason I’m not doing this is because the minimum input from shore power to use power assist is too high for my application so I’m going with dual quattros.
Funny enough my single 8k inverter with ATs on both sides is the same price as 2 5ks in split phase. The ATs are $660 each.
 
Is this an offgrid application, where the inverter is your only source of AC power?
In that case, having two inverters provides redundancy. If ones goes down, the other still provides power for important loads.
(in the event split phase comes only with two inverters stacked in series, have away to deal with that - whether with a transformer, or making sure everybody's refrigerator is on the same phase.)

Mine is grid-backup so I generally don't depend on it. The inverters are wired 2S2P so I can reconfigure by menu to leave out a failed unit, just need to ensure current draw is within the reduced limit. I also have interlocked breakers as bypass switch so I can put the house straight on grid.
 
I realize this is a month old but due to the popularity of this forum I thought I would provide some clarity and comments. Victron does support using a 230V 50HZ inverter re-configured for 240V 60HZ operation combined with an auto-transformer. The Multiplus II is a good cost-effective unit for this type of installation.

The downside of Victron is that currently you will not have UL 1741 certification unless you are using the MultiPlus 12V 120V 3kVA and 24V 120V 3kVA models. That may or may not have an effect depending on your area/application.

The larger question when choosing Victron/SMA over Schnieder/Outback/Magnum might be battery compatibility. A person will find many of the high-end lithium battery manufacturers require an inverter with compatible data communication or the BMS will simply shut down the battery bank if no communication is established.

When it comes to battery integration, Victron/Studer/SMA provides CAN bus data communications ports for integration for lithium battery management systems. This allows the BMS to control the charging parameters in realtime for more precise control over cycling the batteries and preserving their lifespan as they age, making adjustments as needed. Inverters without data integration with the BMS are essentially shooting in the dark. As the cells age, the BMS needs to be able to instruct the charger to reduce the current as the first cell reaches the target voltage to prevent overshooting the charging target voltage (per cell) while the rest of the cells finish charging/balance. With Victron, the beauty of the system is that via the BMS-Can input on the Color Control or Venus GX controllers, the BMS can control all MPPT's and PV inverters (via PF) in the system allowing for seamless AC-Coupled, DC-Coupled, and mixed AC/DC-Coupled operations (typically the very best for medium to large off-grid systems).

With regards to a cost-effective auto-transformer, do some sourcing of the SolarEdge SEAUTO-TX-5000. I recommend looking at places such as RES Supply. You'll find it's cheaper but it's also smaller. 5KW continuous max so bear that in mind.
 
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Just make sure (if applicable) if you use another AT that you can set up a proper neutral bond connect/disconnect (like you can with the Victron setup... you disable the inverter bond relay and trigger the relay in the AT instead).
This was going to be my original design for the RV.
 
Just make sure (if applicable) if you use another AT that you can set up a proper neutral bond connect/disconnect (like you can with the Victron setup... you disable the inverter bond relay and trigger the relay in the AT instead).
This was going to be my original design for the RV.

Good point. Victron has some great layouts but make sure to look closely at the schematics regarding neutral-ground bonding. It can get tricky. Just remember that the neutral from the inverter becomes L2 and you derive a new neutral from the transformer center tap. Disable that relay and do NOT bond the inverter neutral to ground. If you're in a situation where you will need to connect/disconnect the new neutral to/from ground under various conditions with a non-Victron AT, you'll need to use an external relay for that and wire it accordingly to the inverter external ground relay connection. For stationary installations (off-grid particularly) this is not an issue generally but it can be for motive or boating applications.

Here is one of Victron's layouts. It was also linked to in the op. This can also apply to using other 230V 50HZ inverters that are switched to 240V 60HZ. Again just watch the neutral bonding and make sure the manufacturer hasn't permanently bonded inside the inverter.

Don't forget your RCCB/ELCB.

 
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For me the disappointment is that Victron doesn’t make a 48v Multiplus ?
 
For me the disappointment is that Victron doesn’t make a 48v Multiplus ?
I bought a Victron Charge Controller for my neighbor's system. It's my first experience with Victron and I browsed and researched some of their other products while doing it.

Their software is just amazingly well put together.. of all things, that's what impressed me most. Victron has the best software on the market, hands down.

But I'm not crazy about their use of the high frequency architecture in their larger inverter systems. The only saving point is that we don't hear about failures so they must be doing something right.

The only other significant thing I noticed was that they seem to be concentrating on the European 50hz market. Most of their products that catch the eye are all 230v 50hz.. pretty useless in the USA.
 
I bought a Victron Charge Controller for my neighbor's system. It's my first experience with Victron and I browsed and researched some of their other products while doing it.

Their software is just amazingly well put together.. of all things, that's what impressed me most. Victron has the best software on the market, hands down.

Agreed. And the fact that it's open source and modifiable with an active community developing stuff like NodeRed ... yeah. Winner.

But I'm not crazy about their use of the high frequency architecture in their larger inverter systems. The only saving point is that we don't hear about failures so they must be doing something right.

What's the downside of high frequency architectures? I've seen claims of not being able to handle power surges but that's clearly not true of the Victron's...

The only other significant thing I noticed was that they seem to be concentrating on the European 50hz market. Most of their products that catch the eye are all 230v 50hz.. pretty useless in the USA.

All of those should be adjustable to 240/60 with the caveat that 120v loads would require an AT; although it seems most 240v appliances need the neutral anyway for some 120v internals.
 
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