48V 50amp hybrid RV system

[ab_oilpatch68]

Good Morning, looking at putting a 48V system in my RV. I have seen videos that deal with 30amp RV's. Ours is 50amp, what things do we have to take into account for this. Would like to just plug the existing 50amp rv cable into the inverter and run the system that way.

 

[justinm001]

Sounds like you want the Victron MP 2x120 inverter. Does 50a on both legs

 

[12VoltInstalls]

Ours is 50amp, what things do we have to take into account for this.

So that is 50A 240V I assume.

Would like to just plug the existing 50amp rv cable into the inverter and run the system that way.

…so you need at minimum a split phase AIO or other component devices.

I’d pick the AIO.

But which one? Do you have 240V items like a/c or hot water heater? 6000W is roughly 50A, but that’s single phase with usual units.
You have which cord?
I am assuming the far right?

 

[justinm001]

So that is 50A 240V I assume.

…so you need at minimum a split phase AIO or other component devices.

I’d pick the AIO.

But which one? Do you have 240V items like a/c or hot water heater? 6000W is roughly 50A, but that’s single phase with usual units.
You have which cord?View attachment 196415
I am assuming the far right?

Is there an AIO that supports 240v and 120v? I'm assuming OP isn't always going to have 240v as every campground doesn't have 240v 50a. This is where the mp2x120 shines. He can plug into a normal 15a outlet and set the input limit then the MP will power assist to give him 15a plus how ever many watts his inverters rated for. The MP 2x120 will give 240v while on 240v shore but on 120v it'll give 120v on each leg still so everything works except 240v appliances which is rare on an RV.

 

[12VoltInstalls]

Is there an AIO that supports 240v and 120v

Good points. I wasn’t thinking of that.
And I don’t know as it hasn’t crossed my mind before.

 

[Guentha]

I too am building a 50amp RV setup but there seems to be a miscommunication here. RVs are 120 only. there is never a 240 appliance. when hooked to a 240 source each leg is separated and balanced in the breaker box. when a dogbone adapter is used on a 15-30 amp circuit with 1 hot leg it is split and sent to both the legs in the RV. hence...always 120.

I use the 120x2 and it's a great unit but underpowered for most 50 amp coaches it will do a lot but it doesn't even have the power to hold a 13 amp AC running for long without overheating. (and yes they have soft starts.

I am actually here looking for advice on my fix for the 120x2. the biggest problem is the 12v-only option. it works great and very little modification to just drop it in but 12v is really hard when using big battery banks. i have a 17KW bank and it's great but when constantly pulling 200 amps for bigger things it becomes a problem to charge back up. the 80 amp integrated charger will take 15 hours just to charge it back up if nothing else is running. That is a lot of generator time if I am not on shore power

my current solution is to use a 48v inverter solar charger on a huge array and a decent battery bank to feed to 120x2. I will start a new post but I think this will solve all my issues.

 

[justinm001]

I too am building a 50amp RV setup but there seems to be a miscommunication here. RVs are 120 only. there is never a 240 appliance. when hooked to a 240 source each leg is separated and balanced in the breaker box. when a dogbone adapter is used on a 15-30 amp circuit with 1 hot leg it is split and sent to both the legs in the RV. hence...always 120.

I use the 120x2 and it's a great unit but underpowered for most 50 amp coaches it will do a lot but it doesn't even have the power to hold a 13 amp AC running for long without overheating. (and yes they have soft starts.

I am actually here looking for advice on my fix for the 120x2. the biggest problem is the 12v-only option. it works great and very little modification to just drop it in but 12v is really hard when using big battery banks. i have a 17KW bank and it's great but when constantly pulling 200 amps for bigger things it becomes a problem to charge back up. the 80 amp integrated charger will take 15 hours just to charge it back up if nothing else is running. That is a lot of generator time if I am not on shore power

my current solution is to use a 48v inverter solar charger on a huge array and a decent battery bank to feed to 120x2. I will start a new post but I think this will solve all my issues.

Most high end coaches have 240v appliances, residential dryers and electric cooktop. Lots of people are retrofitting 240v mini splits into RVs now too.

They make a 48v 2x120. Or you can just get 2 inverters and program to split phase then you get the same features as a 2x120 but more everything. I have 2 Quattro 48v 5000kw and they're like 70a charger each so 140a at 50v is like 7kw. I only have 10kwh on that bank and recommend charge is 70a on each 5kwh battery so it's perfect. Can kick the genny on and get like 1% charge per minute.

 

[12VoltInstalls]

I too am building a 50amp RV setup but there seems to be a miscommunication here. RVs are 120 only. there is never a 240 appliance.

I understand what you are saying.
The 120x2 is not typical nomenclature as that is usually referred to as 240V split phase: two 120V phases. So while you are not wrong, in a practical sense its jargon is 240V.
I have worked on RV’s that have 240V AC a/c units, though only a few. I can’t remember but have some recollection of seeing a 240VAC electric hot water heater at some point.

when hooked to a 240 source each leg is separated and balanced in the breaker box. when a dogbone adapter is used on a 15-30 amp circuit with 1 hot leg it is split and sent to both the legs in the RV. hence...always 120

The “dogbone” is definitely not split phase as you know.
Just stating the parameters out loud.
For example: my “6250W” inverter generator has an RV-out; it is standard 240VAC across the two hots. This will feed a typical split phase panel.

 

[riecraig]

Could also run a eg4 chargeverter, as they can accept 120v or 240 split phase and charge your 48v bank.

 

[Guentha]

Most high end coaches have 240v appliances, residential dryers and electric cooktop. Lots of people are retrofitting 240v mini splits into RVs now too.

They make a 48v 2x120. Or you can just get 2 inverters and program to split phase then you get the same features as a 2x120 but more everything. I have 2 Quattro 48v 5000kw and they're like 70a charger each so 140a at 50v is like 7kw. I only have 10kwh on that bank and recommend charge is 70a on each 5kwh battery so it's perfect. Can kick the genny on and get like 1% charge per minute.

can you point me to the 48v model of the Victron 120x2? I have the 12v and it's literally perfect other than maxing out at 3000 watts and being 12v. the feature I use the most is the amp limiting and I haven't found this feature anywhere else. I pull up to a friend's house. he gives me a standard 15amp power cord and I tell the victron that is all it has. then it pulls 15amps from there and makes up the rest with the inverter. I can run 2 ac's if I want on a 15amp circuit. basically using the batteries and inverter as a capacitor. As soon as the load drops below 15 amps the batteries get charged back up. If I could get this is 48v with 6000 watts my life would be perfect.

 

[justinm001]

can you point me to the 48v model of the Victron 120x2? I have the 12v and it's literally perfect other than maxing out at 3000 watts and being 12v. the feature I use the most is the amp limiting and I haven't found this feature anywhere else. I pull up to a friend's house. he gives me a standard 15amp power cord and I tell the victron that is all it has. then it pulls 15amps from there and makes up the rest with the inverter. I can run 2 ac's if I want on a 15amp circuit. basically using the batteries and inverter as a capacitor. As soon as the load drops below 15 amps the batteries get charged back up. If I could get this is 48v with 6000 watts my life would be perfect.

You're right there isn't 48v only 12 and 24. But you can just get 2 inverters that aren't the 2x then program as split phase but disable switch as group. I do this with Quattro 5000s 48v and it's perfect. Can run all my 6 acs from 15a if needed or 50a 240v shore or 80a/20kw genset.

Amp limiting with power assist is the best.

 

[Kcmusa]

I also wish Victron would made a higher power 120x2. I have one and would purchase a 48v 6K or higher one.

 

[justinm001]

I also wish Victron would made a higher power 120x2. I have one and would purchase a 48v 6K or higher one.

Doesn't make sense to when you can just get 2 inverters. The 2x120 is special because its small and can be because it's only 3000w. You can't get dual 1500w inverters because not large enough on each leg.

I'm not following on why someone would want a 6k 2x120 instead of 2 3k 120 setup in split phase.

 

[OffGridInTheCity]

Could also run a eg4 chargeverter, as they can accept 120v or 240 split phase and charge your 48v bank.

And perhaps to clarify this thought a bit, the 240v/120v AIO would not have to plug in as it would run 100% off the battery and the Chargeverter(s) or other chargers would charge the battery to support the max load.

You could have multiple plugs - traditional one for the AIO when you have 240v and don't want to fool with it, but then a separate plug for a parallel Chargeverter. This is what I'm doing for my camper so I can run the AIO 3000w at 100% without battery charging diversion and use the generator to put 2500w into the battery directly at the same time.

 

[sunshine_eggo]

I too am building a 50amp RV setup but there seems to be a miscommunication here. RVs are 120 only.

This is a meaningless distinction. When you can plug into a 120/240V split phase source or a 120V source, the details matter. When plugged into your 50A shore power, you will measure 240V between the two legs in the panel.

The potential for two different power sources is a MAJOR consideration when designing a boondocking system that may be plugged into two different kinds of power.

I am actually here looking for advice on my fix for the 120x2. the biggest problem is the 12v-only option.

Also available in 24V

https://www.victronenergy.com/upload/documents/Datasheet-MultiPlus-II-3kVA-2x120V-EN-.pdf

Dual victrons configured for split phase can readily plug into 120/240V split phase and need only a custom 30-50A adapter to only pass L1 to L1 to successfully connect to 120V shore.

 

[justinm001]

This is a meaningless distinction. When you can plug into a 120/240V split phase source or a 120V source, the details matter. When plugged into your 50A shore power, you will measure 240V between the two legs in the panel.

The potential for two different power sources is a MAJOR consideration when designing a boondocking system that may be plugged into two different kinds of power.



Also available in 24V

https://www.victronenergy.com/upload/documents/Datasheet-MultiPlus-II-3kVA-2x120V-EN-.pdf

View attachment 197819

Dual victrons configured for split phase can readily plug into 120/240V split phase and need only a custom 30-50A adapter to only pass L1 to L1 to successfully connect to 120V shore.

Also dual Victrons will allow you to connect to 120v shore and output 240v split phase, allowing us to run all mini-splits, ranges, and dryers.

Idk of any other inverter that would allow this and all seamless for endusers.

The only thing I'm not sure of is how it works with those odd parks that run 2 legs of 3 phase 208 but I'm assuming it'll handle that fine

 

[sunshine_eggo]

Also dual Victrons will allow you to connect to 120v shore and output 240v split phase, allowing us to run all mini-splits, ranges, and dryers.

Yeah. I should have included that.

Idk of any other inverter that would allow this and all seamless for endusers.

almost seamless. You don't want to use a standard 30-50A adapter as you don't want to supply the sam 120V single phase to both inverters.

The only thing I'm not sure of is how it works with those odd parks that run 2 legs of 3 phase 208 but I'm assuming it'll handle that fine

Since those are not 180° out of phase, it would likely treat it as 120V only on one inverter.

 

[Kcmusa]

Doesn't make sense to when you can just get 2 inverters. The 2x120 is special because its small and can be because it's only 3000w. You can't get dual 1500w inverters because not large enough on each leg.

I'm not following on why someone would want a 6k 2x120 instead of 2 3k 120 setup in split phase.

Because I have read running 2 inverters can be a problem if plugged into different sources. RV split 240, 50/ amp and RV 120/30 amp.
The 120x2 makes life easy.

 

[justinm001]

Because I have read running 2 inverters can be a problem if plugged into different sources. RV split 240, 50/ amp and RV 120/30 amp.
The 120x2 makes life easy.

No it's not a problem. If you have dual Victron inverters setup in split phase there's an option to switch as group. Turn that off and if on 120v 1 inverter gets power so uses shore to pass thru and charge battery while 2nd inverter is inverting to make the 240v. If on 240v it just works like normal.

That switch as group is a 1 time thing when programming, so you don't need to make any changes if 240 or 120. Only issue is if using a 50a 240v to 30a 120v dogbone you need one that only provides power to 1 leg. The only thing you need to change is input amperage from 50 to 30 or 15 or whatever but that's the same with the 2x120.

I do this all the time with my RV. I can go as low as 120v 13a but I believe that's because I have Quattro 5000w which has bigger chargers and can't accept so low input.

The 2x120 isn't easier and actually is harder because when inverting you now are pulling both legs on neutral instead of just the unbalanced load. It works at 3000w because if using 50a on shore and only 3000w inverting you're OK but if 6000w you're now pulling 50a through the neutral and 25a through each hot. If 2 inverters you'd be pulling 25a on each hot and 0 on neutral... Or just the unbalanced load. I have 10kw total inverter so it can become a major issue

 

[Kcmusa]

No it's not a problem. If you have dual Victron inverters setup in split phase there's an option to switch as group. Turn that off and if on 120v 1 inverter gets power so uses shore to pass thru and charge battery while 2nd inverter is inverting to make the 240v. If on 240v it just works like normal.

That switch as group is a 1 time thing when programming, so you don't need to make any changes if 240 or 120. Only issue is if using a 50a 240v to 30a 120v dogbone you need one that only provides power to 1 leg. The only thing you need to change is input amperage from 50 to 30 or 15 or whatever but that's the same with the 2x120.

I do this all the time with my RV. I can go as low as 120v 13a but I believe that's because I have Quattro 5000w which has bigger chargers and can't accept so low input.

The 2x120 isn't easier and actually is harder because when inverting you now are pulling both legs on neutral instead of just the unbalanced load. It works at 3000w because if using 50a on shore and only 3000w inverting you're OK but if 6000w you're now pulling 50a through the neutral and 25a through each hot. If 2 inverters you'd be pulling 25a on each hot and 0 on neutral... Or just the unbalanced load. I have 10kw total inverter so it can become a major issue

So what happens when you forget or someone else plugs into a different source.
I don’t need the worry, yes the 120x2 is easy, nothing to change or worry about.
Glad what you have works for you.mine works, just would like a bit more inverted power.