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tim-henderson avatar image
tim-henderson asked

MP2 12v 120x2 power issue

I'm thinking I may not be understanding my system properly. I have a MP2 3k 2x 120v system on a 50amp RV. When trying to run two ACs it fails when trying on generator. I have two generators running that are parallel for 4k max, I put the MP2 to 30amp as it's plugged in to a 30amp kit.

I'll kick on one AC and it draws 1800w, the second AC starts up and should draw the same. Both have soft start. When the second comes on you can here the MP2 struggle and it shuts down. It says L1 I overload. Regardless of which AC I start first it still shuts down and says L1 overload.

Shouldn't the MP2 be able to handle? Any insight for this rookie?

Multiplus-IIstarting generator
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4 Answers
Michelle Konzack avatar image
Michelle Konzack answered ·

You can not run two seperate Generators (non syncronized) on the AC in of two Inverters. I assume, you use split phase right?

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tim-henderson avatar image tim-henderson commented ·
Thanks for the reply. For clarity, I have two Predator 2000w generators to a 30amp parallel kit. A 30amp plug going into my RV AC in.
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mvas avatar image mvas commented ·
30 amps is single phase. Only 1 inverter is being used. Some generators can be wired in parallel, by simply using the "Parallel Wiring" kit.
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tim-henderson avatar image tim-henderson mvas commented ·
I guess that is the part I am missing in understanding. I would think with both generators wired together as I have done, if I set the draw to say 25 amps limit on the MP2, it should be enough power to give to the system to run two ACs drawing a total of 3k watts.


Even if it is not enough to feed it directly shouldn't the MP2 power assist with what is needed from my 300ah battery system?
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derrick thomas avatar image
derrick thomas answered ·

Do you have power assist and dynamic enabled?

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tim-henderson avatar image tim-henderson commented ·
I have power assist enabled. When running one AC it is showing Assisting,
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mvas avatar image mvas tim-henderson commented ·

Why is it assisting with just one A/C unit running? Did you set a limit for the AC Input amps? Is the AC Input "weak"?

Are your batteries fully charged?

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derrick thomas avatar image derrick thomas tim-henderson commented ·
Is weak ac input selected? If so disable it. If power assist is being used with only one ac unit running then something else is going on. Is the fridge an ac? Water heater running on ac? What are the ac output watts reporting on the inverter with one ac running?
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tim-henderson avatar image tim-henderson derrick thomas commented ·
I think weak AC is enabled but not configurable from the remote console settings so I will have to get my laptop and confirm programming when I return home.

To answer the question nothing else drawing except few power outlets charging ipads, fridge is gas. About 1300w drawing when one AC is running.

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derrick thomas avatar image derrick thomas tim-henderson commented ·
Having weak ac input enabled very well could be the issue. Efficiency goes right out the window.
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mvas avatar image
mvas answered ·

Post images of your Power Assist configuration.

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Kevin Windrem avatar image
Kevin Windrem answered ·

Even with soft start on the air conditioners the startup power will be well above the running power. 1800 watts continuous seems a bit high for one air conditioner but if that's what you are measuring then you are right at your 30 amp AC input limit with just the two air conditioners running, not counting startup surge.

The Predator 2000 is 2000 watts STARTING power, 1600 watts continuous, so max of 3200 watts or 26 amps from the two. A bit iffy for starting the second air conditioner without inverter assist. There will be additional restrictions if you are running the generators with ECO mode turned on.

That said, the generators plus assist from the MPII should be enough. You may need to fine tune the input current limit and experiment with dynamic current limit and the assist boost factor.

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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

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