220V from Marine Inverter

[mlwohls]

Might be a stupid question. Background in case it's helpful....

I'm in the middle of installing a sizable (for a boat at least) Solar + LFP system on my new boat (it'll probably end up around 5kW of solar and 25-30wKh of LFP). I'm going about it somewhat in stages so that we can "right size" the final system.

Stage 1 - 3.7kW of Solar (10x LG Neon R 370W panels) + Victron MPPTs + 14.5kWh or LFP (8 x OhmMu150ah/12V).
Stage ??? - Do I do inverters now or later (see below on the dilemma). Currently the boat has 2 x Magnum 2812 inverters (2800W from 12V bank)
Stage 2 (this summer, after 3-4 months in the Bahamas) - Add more solar + LFP, new AirCons (likely FrigoMar, only marine AC's with built-in inverters), possible CZone digital switching, etc

DILEMMA/QUESTION:
All of the AirCon systems that I'm looking at run on 220V/60hz. However, all of the inverters I'd like to use are only 110V/60hz (I'm trying to do the whole system with Victron so everything talks together and I can access info on mobile and chartplotter). Is there a feasible way to get 220V/60hz from a 110V/60hz inverter (or 2 inverters, I'm currently considering 2 x Victron Quattro 5000W inverters). The reason why this is somewhat a pressing question for STAGE 1 is I'd LIKE to switch over to 24V now, as that makes sizing the MPPTs and wiring, etc much more manageable.

Thanks for the help/feedback. (NOTE: Don't pull punches if I'm really off base, I can have thick skin when needed )

 

[FilterGuy]

@Justin Laureltec is a Victron Gedi. You might want to reach out to him to see if there is a way to stack the Victron to get 220.

 

[FilterGuy]

I see this in the Quatro data sheet.
"Parallel and three phase applications can be configured with VE.Bus Quick Configure and VE.Bus System Configuratorsoftware. "
That is not a complete answer but it is sure promising.

 

[mlwohls]

@FilterGuy Thanks for the heads up on @Justin Laureltec (I'd love to hear your thoughts!)

In regards to the parallel setup, it's my understanding that it simply increases the total output of 2 inverters but keeps the voltage the same (2 x 5,000W Quattros just gives you 10,000W but still at 110V, effectively just giving you more amperage to use). I think that capability is required to hook them in parallel as the 2 inverters need to synch their "sine waves" (or else you'd have a jumbled mess of overlapping/canceling sine waves).

 

[mlwohls]

I may have found the answer? I might have to stack an AutoTransformer (step up/down transformer) between the inverters and the AirCon units.

Autotransformer - Victron Energy

Use the Autotransformers for step up, step down and split phase output balancing purposes. Find a Victron Energy dealer near you.

www.victronenergy.com

The datasheet has a diagram for this exact situation (pasted below, hopefully the image comes through). I BELIEVE this would mean I can likely switch over to a 24V system TODAY starting with 1 Quattro 5000 and then add the 2nd Quattro (in parallel) and an AutoTransformer this summer when we switch out the AirCons (and maybe add a clothing dryer, which may be 220V electric, we'll see).

 

[Justin Laureltec]

@mlwohls , sure, this is easy and you can do it with any of the Victron MultiPlus or Quattro models - you need two, though, but you (in a few words) connect two to the same AC input source, chain them together with a VE.Bus cable (normal CAT6 RJ45), connect to them using a laptop and an MK3-USB Interface, and using VE.Bus Quick Configure you tell them to output split-phase 180° 120/240. This is called parallel-split mode, which is an important distinction from simple parallel-mode, which only increases output VA.
Alternatively, you can use a single MultiPlus or Quattro outputting normal 120 and install an Autotransformer on the output to split to 120/240 - either would work, but you end up with a higher capacity from using two Multis in parallel-split mode.

 

[mlwohls]

@Justin Laureltec Thanks! Great to hear I may not even need the AutoTransformer. I'll do more research to make sure I understand the "Parallel-Split" setup. My biggest concern for NOW was buying the first Quattro 5000 and then kicking myself down the line if it wouldn't work with the eventual AirCons, etc that we choose. Sounds like I don't have to worry as it'll be possible one way or another (of course as long as I stick with 60hz AirCons)

Thanks again!

 

[Justin Laureltec]

@mlwohls , no worries! Check out the parallel and three-phase VE.Bus systems manual; there are also links in that manual that lead to other useful documents that will help answer some of the common wiring and other installation questions as well.
You can also download the Quattro user manual from Victron and scroll wayyyyyy down to the Appendixes, which give some advice on connection methods for parallel-split connection (they generally show either parallel or three-phase installations, but the parallel-split configuration is just three-phase minus one).

 

[mlwohls]

@Justin Laureltec If I'm wearing you out, feel free to disregard! In researching the Parallel-Split setup (before I saw your latest reply with hints about where to look), I came across this blog post:

Generating a 120/240 Volt split phase power supply from an inverter

They outlined what I think you're saying, AND they also suggested another way to do it...
A) Buy a 230V/50hz Quattro and adjust it to 60hz in the config
B) Add an autotransformer behind that (and heck, the 100A autotransformer is only $150 more than the 32A autotransformer)
As I understand it, the reason why they were suggesting this is that you end up with much more flexibility between loads on the 120V legs (as with the other setup, there would be no chance to shift load dynamically between the two different 120V legs).

Sharing what I found in case (a) I'm missing something and (b) in case it is helpful for others later on.

Thanks!

Michael

 

[FilterGuy]

@mlwohls , sure, this is easy and you can do it with any of the Victron MultiPlus or Quattro models - you need two, though, but you (in a few words) connect two to the same AC input source, chain them together with a VE.Bus cable (normal CAT6 RJ45), connect to them using a laptop and an MK3-USB Interface, and using VE.Bus Quick Configure you tell them to output split-phase 180° 120/240. This is called parallel-split mode, which is an important distinction from simple parallel-mode, which only increases output VA.
Alternatively, you can use a single MultiPlus or Quattro outputting normal 120 and install an Autotransformer on the output to split to 120/240 - either would work, but you end up with a higher capacity from using two Multis in parallel-split mode.

Thanks @Justin Laureltec. I figured you would know.

 

[burnin_daylight]

Have you considered going to 48V inverters? I just ask because depending on how big your a/c units are, you could end up with a pretty high amp draw. I have 3 a/c units on my houseboat that run off 2 of the 48/5000 Victrons configured in split phase 120/240. It works amazingly well and keeps the amps low.

24V should work for you, but if you have lithium batteries, the BMS may not like the high amp draw. Just a thought

 

[FilterGuy]

I have 3 a/c units on my houseboat that run off 2 of the 48/5000 Victrons configured in split phase 120/240. It works amazingly well and keeps the amps low.

What do you do for your various 12V devices? Do you use a step down buck converter?

 

[burnin_daylight]

I have a 12V 100Ah lithium feeding the 12V panel, and have a Victron 48-12 converter keeping it charged. If for some reason the converter fails or the 48V battery goes offline, at least I have backup power for some small lights and waterpump

 

[mlwohls]

@burnin_daylight I haven't found the Victron 48-12 step down converter. Do they still make it? I know they have a 24/12 in either 32A or 100A, but I haven't found the 48/12?

 

[Justin Laureltec]

@burnin_daylight I haven't found the Victron 48-12 step down converter. Do they still make it? I know they have a 24/12 in either 32A or 100A, but I haven't found the 48/12?

You'll be looking at the Orion-Tr 48/12 Isolated DC-DC Converters... available in 9, 20, or 30A models.

 

[burnin_daylight]

Justin is correct. I used the 48/12-20 Isolated. Zero issues with it. I used the potentiometer to set voltage at 13.4V when connected.

48V really is the way to go for high draw appliances. Much easier to find a BMS to handle 80A draw @48V than 160A draw @24V.