Recommendations needed please. Inverter for RV.

[Sean Steele]

Hello everyone. I am revisiting the system plan for my Fifth wheel. I originally planned on using a Victron Multiplus, the one for 50A RVs. The main reason for wanting this was its ability to use incoming AC and battery power at the same time. so I could use my tiny inverter generator to run my rooftop air conditioner. Future plans for the air conditioner are to remove the roof top air and install a mini split. This eliminates the need for the boost from the inverter to run the unit, my generator can run the mini split on its own. Anyway. I will still be using Victron for everything else in the system for the communication capabilities. I would prefer to use a Victron inverter but the 12v options only go up to 1200va. I am looking for something between 3k and 5k watts. I want to stick with 12v for my battery power for simplicity so I don't have to include a DC-DC converter in my system. I have seen some of the new All-in-one units being compatible with the Vitron communication protocols. Are there any "regular" inverters out there that can communicate with Victron? By "regular", I mean that I don't need an inverter/charger.

I have a 50A automatic transfer switch that I bought many moons ago for a different RV. All of the battery stuff will be going in the front bay of my fifth wheel but the power cable connects at the rear and the breaker box is also in the rear. I removed the converter/charger when I swapped the camper from 30A to 50A. I plan to install the transfer switch where the converter used to be. I had a convoluted plan for relocating the "service entry" point to the left front area of the camper when I was going to use the Multiplus so that I wouldn't have to run the expensive 6-4 cable from one end of the camper to the other and back.

 

[Rocketman]

I assume you are in North America.
Use a Victron Multiplus 12/3000 2x120v.

This will work on both the 50a (which is like 240v) and 30a (120v) automatically.

It will run an RV air conditioner (if it has a Micro Air EZ start on it). Plus your Microwave (at separate times).

Here is the spec sheet:

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

I wish this was out when I changed out my inverter and got a Multiplus 12/3000

Good Luck

Edit: if you really needed more power and have the batteries and cables, I believe you could even parallel two of these units together.

 

[justinm001]

They make much larger victron inverters. I have a 5kw 12v quattro.

4/0 gauge wire can only handle 260amps so pushing a ton of power from 12v is very hard. You'll find that it's cheaper to go 48v when trying to put 3kw or more. Even my 48v inverter was like 2900 vs 3700 for 12v.

 

[sunshine_eggo]

They make much larger victron inverters. I have a 5kw 12v quattro.

4/0 gauge wire can only handle 260amps so pushing a ton of power from 12v is very hard.

This is not accurate without qualifications. That is true for 90°C rated insulation enclosed in a raceway at 30°C ambient. 4/0 "battery wire" can handle as much as 445A:

Battery Cable Flexible OFC Copper UL MTW/THW/SGT SAE J1127 - By the Foot

www.batterycablesusa.com

The amount of voltage drop may be excessive though.

Hello everyone. I am revisiting the system plan for my Fifth wheel. I originally planned on using a Victron Multiplus, the one for 50A RVs. The main reason for wanting this was its ability to use incoming AC and battery power at the same time.

Only if you're talking about PowerAssist.

If supplied by 120VAC (30A power), the inverter will charge and pass through shore to loads and short L1 to L2 to provide 120V to both legs of panel. The inverter can powerassist both legs.
If supplied by 120/240VAC (50A power), the inverter will charge and pass through to loads on L1, powerassist on L1 and pass through shore to L2.

so I could use my tiny inverter generator to run my rooftop air conditioner.

How tiny?

Again, only if you're talking about powerassist.

Future plans for the air conditioner are to remove the roof top air and install a mini split. This eliminates the need for the boost from the inverter to run the unit, my generator can run the mini split on its own.

like.

Anyway. I will still be using Victron for everything else in the system for the communication capabilities.

Hubba Hubba.

I would prefer to use a Victron inverter but the 12v options only go up to 1200va. I am looking for something between 3k and 5k watts.

HUH? The one you're talking about "for 50A RVs" is a 3kW unit:

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

I want to stick with 12v for my battery power for simplicity so I don't have to include a DC-DC converter in my system. I have seen some of the new All-in-one units being compatible with the Vitron communication protocols.

I haven't. Please link.

Are there any "regular" inverters out there that can communicate with Victron? By "regular", I mean that I don't need an inverter/charger.

No. Victron is compatible with Victron. The only exception I'm aware of is Fronius for grid tie inverters... but you still need a Victron inverter to interface with it.

 

[justinm001]

This is not accurate without qualifications. That is true for 90°C rated insulation enclosed in a raceway at 30°C ambient. 4/0 "battery wire" can handle as much as 445A:

Battery Cable Flexible OFC Copper UL MTW/THW/SGT SAE J1127 - By the Foot

www.batterycablesusa.com

The amount of voltage drop may be excessive though.



Only if you're talking about PowerAssist.

If supplied by 120VAC (30A power), the inverter will charge and pass through shore to loads and short L1 to L2 to provide 120V to both legs of panel. The inverter can powerassist both legs.
If supplied by 120/240VAC (50A power), the inverter will charge and pass through to loads on L1, powerassist on L1 and pass through shore to L2.



How tiny?

Again, only if you're talking about powerassist.



like.



Hubba Hubba.



HUH? The one you're talking about "for 50A RVs" is a 3kW unit:

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

I haven't. Please link.



No. Victron is compatible with Victron. The only exception I'm aware of is Fronius for grid tie inverters... but you still need a Victron inverter to interface with it.

The voltage drop on 260a is a bunch already. I'm running 4/0 on my 5k 12v inverter and if I pull too much it'll trigger the low voltage on the inverter. Not sure of the calculation of running 300amps+ on 12v regardless if the cabling can handle it

 

[MisterSandals]

I want to stick with 12v for my battery power for simplicity so I don't have to include a DC-DC converter in my system.

A 48 to 12V converter might be simpler, cheaper and more reliable than some of the hoops you are expecting to jump thru running 12V at hundreds of amps. It may sound scary and foreign but its a simple thing between a 48V battery and your existing 12V fuse/breaker box.

How many amps at 12V would you need to convert from 48V? Are the bulk of you big loads 120V AC?

 

[justinm001]

A 48 to 12V converter might be simpler, cheaper and more reliable than some of the hoops you are expecting to jump thru running 12V at hundreds of amps. It may sound scary and foreign but its a simple thing between a 48V battery and your existing 12V fuse/breaker box.

How many amps at 12V would you need to convert from 48V? Are the bulk of you big loads 120V AC?

Another thought is an ac to 12vdc converter as you can easily get 100amp ones. Might be a bit less efficient but it's cheaper than multiple DC dc-dc

 

[sunshine_eggo]

The voltage drop on 260a is a bunch already. I'm running 4/0 on my 5k 12v inverter and if I pull too much it'll trigger the low voltage on the inverter. Not sure of the calculation of running 300amps+ on 12v regardless if the cabling can handle it

Sounds like a connection issue, length issue or a configuration issue:

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

3 feet of 4/0 @ 12V, 466A only drops 0.14V

 

[justinm001]

Sounds like a connection issue, length issue or a configuration issue:

Voltage Drop Calculator

This free voltage drop calculator estimates the voltage drop of an electrical circuit based on the wire size, distance, and anticipated load current.

www.calculator.net

3 feet of 4/0 @ 12V, 466A only drops 0.14V

Thanks!

 

[Sean Steele]

@sunshine_eggo , That is a lot to unpack. For clarification, I referenced the Multiplus saying that it was my original thought. I have decided that I no longer need the power assist feature. I also do not want or need an inverter/charger because it would require moving the shore power connection to the front of the camper so that I don't have to run heavy 6-4 conductor cable from one end to the other. In short, I want the multiplus without the multi or the plus. I just need a 12v 3-5kW inverter. The Phoenix only goes to 1200VA. Also, Victron uses VA in their products. The 3000VA Multiplus in only a 2400 Watt inverter as per their documentation, "Cont. output power at 25°C (3) 3000 VA, Cont. output power at 25°C 2400 W, Cont. output power at 40°C 2200 W, Cont. output power at 65°C 1700 W". I just want something that is around 3600Watts continuous. Since the Multiplus was on my list, I already have the 4-0 wire and will have over 400AH worth of batteries before I install the new inverter.

My Inverter Generator is 2200 watts.

Hell, If the Phoenix 12/1200 were capable of being linked to provide 2400, I would consider them just to stay in brand.

As for the desire to stay with Victron for the communication thing. I just really like the user interface thing, the Cerbo. That screen with the infographics on it is really awesome. I have a long HDMI cable and a USB mouse set aside so I can check my system status on the 55" TV in the camper. lol



I am tempted to go 48v considering the "server rack" batteries that are all the rage now. However, my rig has a 12 hydraulic pump for the slide out that is power hungry. I would need a 30A dc-dc converter as well as a small 12v battery just for that.

I went looking for a link to the all-in one I was talking about and realized that I was getting it mixed up with an Epoch Battery I had recently seen a video for. it has Victron communication protocol. I have a bad habit of watching youtube videos for hours on end and sometimes getting different products mixed up.

 

[Sean Steele]

A 48 to 12V converter might be simpler, cheaper and more reliable than some of the hoops you are expecting to jump thru running 12V at hundreds of amps. It may sound scary and foreign but its a simple thing between a 48V battery and your existing 12V fuse/breaker box.

How many amps at 12V would you need to convert from 48V? Are the bulk of you big loads 120V AC?

The biggest load is the hydraulic pump for the slide. It can draw up to 30A at 12 in normal operation. It isn't scary at all. I know that if i decide to go the 48V route, it will add at least one component to my system. I would also put a small 12v battery in line with it to handle big inrush currents.

 

[sunshine_eggo]

12V 3000W inverter:

https://www.victronenergy.com/upload/documents/Datasheet-Inverter-3000VA-120V-EN.pdf

ALL inverters are rated in VA. Victron confuses everyone by being honest about it. Dig in to many "Watt" specifications, and you'll find honest specs are really VA. The short of it is:

You will be able to draw 3000W of resistive loads.
You will be able to draw 2400W of inductive loads assuming 0.8 power factor.

Victron inverters are also VERY tolerant of overload. Ah... I found my rant:

Is the Victron Multiplus 12/2000 worth the extra bucks?

I am at the point in my build that I need to pull the trigger on a Victron Multiplus 2000w inverter/charger. This will be in a E250 van conversion. All I need is power to run a small microwave and a coffee maker (not at the same time). My brain is on overload from all the brands, features...

diysolarforum.com

30% overload for 30 minutes provided it doesn't overheat due to inadequate ventilation, high ambient or high DC ripple (too much DC voltage drop).

That means 3900W for up to 30 minutes.

 

[Sean Steele]

12V 3000W inverter:

https://www.victronenergy.com/upload/documents/Datasheet-Inverter-3000VA-120V-EN.pdf

ALL inverters are rated in VA. Victron confuses everyone by being honest about it. Dig in to many "Watt" specifications, and you'll find honest specs are really VA. The short of it is:

You will be able to draw 3000W of resistive loads.
You will be able to draw 2400W of inductive loads assuming 0.8 power factor.

Victron inverters are also VERY tolerant of overload. Ah... I found my rant:

Is the Victron Multiplus 12/2000 worth the extra bucks?

I am at the point in my build that I need to pull the trigger on a Victron Multiplus 2000w inverter/charger. This will be in a E250 van conversion. All I need is power to run a small microwave and a coffee maker (not at the same time). My brain is on overload from all the brands, features...

diysolarforum.com

30% overload for 30 minutes provided it doesn't overheat due to inadequate ventilation, high ambient or high DC ripple (too much DC voltage drop).

That means 3900W for up to 30 minutes.

This wins the internet. How the hell did i not find this myself? I checked the victron page and three suppliers. I'll go on a hunt.

P.S. Thank you for the info on the VA thing. I did not know that. It makes sense.

Thanks again. I knew I could count on this forum for good info.

EDIT: Of course, now that I know what to look for, I find it on NAZ and even Amazon. AND it costs more than the Multiplus......

 

[Sean Steele]

Well, after all this, I may be back to the Multiplus. Its cheaper and has much more functionality. Even though I may not need the added functionality, paying less to get it just makes sense.

 

[sunshine_eggo]

Maybe an auxiliary umbilical that just attaches directly to the MPII???

 

[Sean Steele]

Adding a second shore power connection would require the same work as moving it. Breaker box is at the back and inverter is going in the front with the batteries.

Or were you suggesting something different? Are you saying add a secondary input just for the MPII, like a small 30A or 20A port and leave the normal shore power connection at the rear? Wouldnt this bypass the transfer switch and possibly allow the inverter to try to feed power to the breaker panel while plugged into shore power? I'm confused.

I considered connecting the MPII like a normal inverter and feeding it into an external transfer switch but I would still need to make the run of 6-4 cable from the inverter to the breaker panel at the back of the camper. This would eliminate the ability to use the added features that I am paying less for. lol

 

[sunshine_eggo]

It was an off-the-cuff remark. Not sure if it makes sense.

 

[HRTKD]

When I installed my Multiplus 12/3000 in my 30 amp trailer I did run new cable from the automatic transfer switch to the Multiplus. The distance went from maybe 2' to about 10' and I wanted to minimize the voltage drop. I did use 6 gauge AC cable. I don't remember if it was 6/3 or 6/4 since it was free from a friend. It's certainly not as easy to work with as 2/0 welding cable.

The Multiplus has been bulletproof.

You can limit the amps going into the Multiplus on the fly using either the Cerbo GX with Touchscreen or using Victron's wall mounted controller. With this you could run new cable from the shore power to the Multiplus and keep the amps within the rating of the new cable (if you didn't run 6/4). It's not how I would do it because sooner or later someone who doesn't know what they're doing will change the setting.