Victron Autotransfomer with Multiplus II 2x120

[RDTC]

Is anyone using a Victron Autotransformer to split the phase on an Onan 5500 generator.

I have a Pinnacle. 50 Amp shore power, 5500 Onan generator, with a Victron Multplus II 2x120.

The generator has 2 load wires on the same phase. When using the OEM transfer switch configuration to feed the Multiplus on generator. Only 1 leg of generator power comes through. Cutting the usable generator output by 50%.

I see some people bonding the 2 generator load lines together and feeding 1 side of the transfer switch. Letting the Multiplus auto disconnect L2 input and auto connect L1 & L2 output. I would rather not do this.

My thought is to use the Victron Autotransformer 100A to split the generator phase. Looking for anyone else that has done this.

[kirkelli]

is your generator putting out 220 or two 110 feeds. You have to remember, your coach 50 Amp panels is not a true 220 panel but two 110 panels. The 220 comes in to the panel feeding 110 on two sides of the panel. The MultiPlus should e wired so that your 50 Amp feed is wired to the MultiPlus then back to your 50 Amp Panel. The Generator would feed the transfer switch before the Multiplus. The Victron site will have some white papers detailing connection procedures..
i.e.

https://www.victronenergy.com/live/multiplus_faq

https://www.victronenergy.com/media/...interface.html

[Kevin Cooper]

What are you trying to achieve? If you are trying to get Equilivent power to a shore power connection, that is not possible. A little math. Shore power is 50a 120/240 volts. So 50 x 240= 12,000 watts at full output. Your generator is 5,500 watts. There is no way to get 12,000 watts out of the generator. No equipment can increase the watt capacity of a generator.
If I’m totally off base, please explain what you are wanting for an outcome.
Respectfully, Kevin
After thought, if you connect a Victron and solely using the generator, you actuall have less power available for the RV appliances. The Victron uses power, therefore, it is lost capacity, not increased.

[kirkelli]

Originally Posted by Kevin Cooper

What are you trying to achieve? If you are trying to get Equilivent power to a shore power connection, that is not possible. A little math. Shore power is 50a 120/240 volts. So 50 x 240= 12,000 watts at full output. Your generator is 5,500 watts. There is no way to get 12,000 watts out of the generator. No equipment can increase the watt capacity of a generator.
If I’m totally off base, please explain what you are wanting for an outcome.
Respectfully, Kevin
After thought, if you connect a Victron and solely using the generator, you actuall have less power available for the RV appliances. The Victron uses power, therefore, it is lost capacity, not increased.

actually, with the Multiplus you do get 'Power assist' and you can draw more wattage than the generator provides. But it's all dependent on your battery pack and wattage of the inverter(s)

[Kevin Cooper]

You are adding equipment that increases power available to the coach. It does not increase power coming from the generator. I still do not understand the desire to increase available power. If you have a 20kw generator, how many kw is it producing when it up and running? I used to ask similar question in electrical classes. Can anyone answer the question?

[craigav]

My comments are inline in blue.

Originally Posted by RDTC

Is anyone using a Victron Autotransformer to split the phase on an Onan 5500 generator.

You are not going to find anyone who has done exactly what you are describing as the result would not provide any power output.

I have a Pinnacle. 50 Amp shore power, 5500 Onan generator, with a Victron Multplus II 2x120.

The generator has 2 load wires on the same phase. When using the OEM transfer switch configuration to feed the Multiplus on generator. Only 1 leg of generator power comes through. Cutting the usable generator output by 50%.

I am not sure why Onan created a setup with 2 load wires on the same phase however I would suspect that each load wire is protected at half the potential of the generator (50% as you stated)

I see some people bonding the 2 generator load lines together and feeding 1 side of the transfer switch. Letting the Multiplus auto disconnect L2 input and auto connect L1 & L2 output. I would rather not do this.

I would rather not do this as well (unless Onan approves of combining both lines for this purpose). I would check with Onan first in order to determine if they allow for combining both output lines or advise against doing so and if they do state combining both lines is acceptable, then I likely would combine them (which would negate the need for the autoformer).

My thought is to use the Victron Autotransformer 100A to split the generator phase. Looking for anyone else that has done this.

An Autoformer (really any transformer) cannot take a single leg (or two lines in phase with each other) as input on both input connections and then have any power output. In other words if the two legs were opposed with each other at 180 degrees (which would be 240v) then you could use an autoformer for this purpose.

I suspect your goal would be to use both outputs (uncombined) and have one line going to the one input side of the autoformer and the other other line going to the other input side of the autoformer in order to realize the full potential of the generator however, because both output lines of the generator are actually in phase with each other, then that means there would be no voltage potential across the legs (if you connect a voltage meter lead to line 1 and the other lead to line 2 you would (if they are in phase with each other) measure zero volts). While it is possible for an autoformer (or buck transformer) to take 120v and double it to 240v and then even split the phase on that, you would still be limited in the scenario you described if you use only one output line (instead of combining both lines). The only way to get double the wattage output of any single line would be to combine both line1&2 (or use each line independently of each other as likely Onan intended) although as you stated you would prefer not to do so and even if you did prefer to do so, I would highly recommend checking with Onan first as doing so could possibly damage the generator under certain conditions.

Not too mention, if you did decide to combine line 1&2 then using an autoformer would no longer provide the benefits you are trying to accomplish.

~CA

[Kevin Cooper]

An Onan 5500 watt generator is 120 volts only. So, it’s maximum capacity is 45.83 amperes. Since this is a continuous rating the normal overcurrent protection is 45.8 x 1.25= 57.25. Or 60 amp breaker. The load is divided into two breakers. There are two options when buying the generator (2) 30a breakers or (1) 30a and (1) 20a.
So, if your generator has (2) 30a breakers, it is capable of delivering its maximum capacity. It is not only delivering half of its capacity.

[craigav]

Originally Posted by Kevin Cooper

An Onan 5500 watt generator is 120 volts only. So, it’s maximum capacity is 45.83 amperes. Since this is a continuous rating the normal overcurrent protection is 45.8 x 1.25= 57.25. Or 60 amp breaker. The load is divided into two breakers. There are two options when buying the generator (2) 30a breakers or (1) 30a and (1) 20a.
So, if your generator has (2) 30a breakers, it is capable of delivering its maximum capacity. It is not only delivering half of its capacity.

Except it would deliver only ~50% of its rated capacity if you only used one line as the OP is asking about doing and this would be due to only having a single 30a breaker for each output line. I haven't read any specifics for the Onan 5500 other than having read comments over the years where I seem to remember some owners stating that Onan states not to connect (combine) the two output lines (which could be incorrect and for reasons I have never looked into). ~CA

[Vicr]

You guys are spending a lot of time and energy responding to someone who hasn't told us what he is trying to achieve. As someone who spent 38 years designing, building and managing electrical construction projects I would always ask "what do you want to achieve"?

[craigav]

Originally Posted by Vicr

You guys are spending a lot of time and energy responding to someone who hasn't told us what he is trying to achieve. As someone who spent 38 years designing, building and managing electrical construction projects I would always ask "what do you want to achieve"?

I did have to read the OP's comment more than once. However after doing so, I am confident that I know exactly what the OP is trying to achieve. (Which simply stated is to obtain 100% output of the Onan 5500 without combining both lines (and in particular with the setup he currently has) and asking if a possible solution for accomplishing this would be by adding a Victron Autoformer to his current setup, and the answer for that would be "no".)

I completely agree though that it is very important to understand prior to starting any project (or even prior to giving advice on how to accomplish such a project related goal) by asking "what do you want to achieve". ~CA

[Kevin Cooper]

I guess I misunderstood the question! If he is asking about the Victron needing one input because of 120 volts only, that is not necessary.
The Victron has input L1, L2, N. And it automatically senses that it is 120 volts only or 120/240 volts. The 50amp automatic transfer also transfers both L1 and L2 regardless of the voltage. So, there should be no need to combine the two lines from the generator. This comment is based on wiring diagrams found for both devices.
I’m very sorry for not understanding the question.

[Vicr]

Originally Posted by craigav

I completely agree though that it is very important to understand prior to starting any project (or even prior to giving advice on how to accomplish such a project related goal) by asking "what do you want to achieve". ~CA

I did sit in more than one pre-construction meeting and when the customer/client asked for something rather outlandish I did reply with "We can do anything, it just takes money".

[craigav]

Originally Posted by Kevin Cooper

I guess I misunderstood the question! If he is asking about the Victron needing one input because of 120 volts only, that is not necessary.
The Victron has input L1, L2, N. And it automatically senses that it is 120 volts only or 120/240 volts. The 50amp automatic transfer also transfers both L1 and L2 regardless of the voltage. So, there should be no need to combine the two lines from the generator. This comment is based on wiring diagrams found for both devices.
I’m very sorry for not understanding the question.

You are on the right track but not quite there yet. It is important to note (although not clearly stated) that it is the Multiplus II that senses the power coming in, from the generator, on L1 is of the same phase as on L2 and then drops L2 (because it isn't split-phase 240v coming in) which then leaves only L1 coming into the Multiplus II which is protected by a single 30a breaker therefore limiting the generators output capacity to the amount of power that the one breaker would support. ~CA

[Kevin Cooper]

A 5500 comes with two breakers that both go through the ATS incoming as L1, L2,N. Shore comes in L1, L2,N. Output is L1, L2,N. Output goes to multiplus and wires L1 to L1 and L2 to L2 N to N. The Victron unit automatically senses and accepts either 120/240 volts from shore or 120/120 from the generator. At least that is what the Victron wiring schematic shows. The output of the 50 amp ATS is (2) line and neutral no mater what the input voltage. 240 volts is not used in RV’s, even though it is there.
So, you would not need or want to combine the two lines coming from the generator.

[craigav]

Originally Posted by Kevin Cooper

A 5500 comes with two breakers that both go through the ATS incoming as L1, L2,N. Shore comes in L1, L2,N. Output is L1, L2,N. Output goes to multiplus and wires L1 to L1 and L2 to L2 N to N. The Victron unit automatically senses and accepts either 120/240 volts from shore or 120/120 from the generator. At least that is what the Victron wiring schematic shows. The output of the 50 amp ATS is (2) line and neutral no mater what the input voltage. 240 volts is not used in RV’s, even though it is there.
So, you would not need or want to combine the two lines coming from the generator.

Perhaps a picture would help (the right side of the image is the MultiPlus II). Forget for a moment about the transfer switch as it really doesn't come into play. When the Multiplus II senses 120vac input notice how the transfer relays (I highlighted in red) are configured. In this configuration only L1 of the generator will provide power to the MultiPlus II. L1 at the generator is protected by a single 30a breaker. In this configuration, the MultiPlusII will never receive more than ~30a of current from the generator as exceeding 30a will trip the breaker.

Check out on the first page of the PDF in the link below and notice the difference with the transfer relay configuration when the MultiPlusII does sense 240vac split phase (which it doesn't sense with the Onan 5500). https://www.victronenergy.com/upload...2x120V-EN-.pdf

[Kevin Cooper]

Craig, You are right again. I missed the open relay. I found another piece of info that says you must use two Victron to get 120-0-120.
So, all in, still leave the gen and transfer alone, and connect each line off of the ATS to L1 along with neutral. Does that sound right?

[craigav]

Originally Posted by Kevin Cooper

Craig, You are right again. I missed the open relay. I found another piece of info that says you must use two Victron to get 120-0-120.
So, all in, still leave the gen and transfer alone, and connect each line off of the ATS to L1 along with neutral. Does that sound right?

LOL, it is all good (I enjoy these topics but I also understand that they are deeper than what many RVr's care to discuss, but some do care).

In any case, the MultiPlus II provides for 2x 120v line outputs off of a single 120 input (so you can power both sides of the breaker panel), and this is where we circle back to the OP's question and inline with your comment "connect each line off of the ATS to L1" which is where the previous "combine" comments come into play. (Keep in mind that connecting L1&L2 right off of the ATS's output isn't going to work out well when plugging into a properly wired 50a RV receptacle as any combining from the generator would need to occur before the ATS)

I haven't researched this, but I believe Onan specifies not to combine the two outputs (again, I don't know if that is true or what their reasoning would be and I would suggest to verify this with Onan prior to combining them). In any case, if Onan states that the L1 and L2 can be combined then what you stated is what I would do as well and what I would recommend doing (and is what I was saying earlier about combining the two line outputs). All this relates back to the beginning as to why the OP was asking (in my words now) "Without combining the two lines, can I use an Autoformer to achieve the same\similar results?" and the answer is "no" because the autoformer's two inputs can't be from the same 120v phase (which is what the onan 5500 two line outputs are). ~CA

[RDTC]

Great discussion everyone. I did start the post towards the end of my situation. Let me start from the beginning.

Went camping last month. Very hot weather. An hour before the campground. Stopped, started the generator, with the plan to turn on 1 or 2 AC units. Turned on 1 AC and the generator 30amp breaker tripped. Was very frustrated. This was the first time I had tried this. Thought the generator would have no problem. I have a Cerbo/Touch. Took a picture of it during the event. Picture attached.

Picture taken with no AC running. Generator load on L1 is 2695 Watts. Load on L2 is 0 Watts. Was initially surprised at the load on L1. Did not understand why L2 was 0. But, after more thought on the load. The Multiplus charger is drawing 1440, refrigerator is drawing 890, and that leaves 405 of miscellaneous other loads.

After reseting the generator breaker. I retried turning on the AC and watching the Cerbo/L1 load. It briefly hit 4400 watts and tripped the breaker again.

I switched the refrigerator to LP and lowered the Multiplus charge current max to 80 amps. Retried the AC. L1 was 2700 watts. The wife was very frustrated. The planned 10 min stop. Which was 60 min from the campground. Took about 90 min. But, we got the AC running. The unit was cool when we arrived at the campground.

I was not aware of this situation. With my generator & Multiplus combo. No L2 output. Others might be unaware as well. Can be worked around. But, I want to be able to use the full generator output. Would like to be able to run all 3 AC units if desired.

[RDTC]

After lots of reading. I believe the Victron Autotransformer will resolve the situation.

Found a YouTube video from Battle Born. They ran one leg from the generator through an Autotransformer.

https://www.youtube.com/watch?v=wIi8_J2Zb_Q

With Battle Born solution. You can use the full generator power. But, you can not exceed either leg on the generator.

By bonding both generator legs together. I contacted Onan, said this is okay on my generator model. The autotranformer will split the phase. And, allow up to full generator power on either autotransformer output leg individually. Not to exceed the 100 amp autotransformer rating. This will allow using all of the generator power.

This is the theory. Would like input from someone that has done it.

[craigav]

As long as Onan doesn't have any specific reason not to combine the two lines, then combining them is what would work best for obtaining the full output of the generator into the multiplusII. Is your transfer switch before or after the Multiplus? The reason I ask is its location would make a difference in where to combine the generators L1 and L2.

Something to emphasize here (for those who don't already know this) NEVER EVER combine both legs of a standard 50A RV outlet, inlet, or a standard 50RV power cord or most every generator you ever see that has 2 Line (L1&L2) outputs. What is being discussed in this thread is very specific to the Onan 5500's output and the MultiplusII inputs and is a special case configuration that would not apply otherwise. ~CA