Stormy R. avatar image
Stormy R. asked

Does the Victron Autotransformer balance and step up simultaneously?

Or is it one or the other?

This product is for balancing, step down, or step up.

But does it only do one at a time. Obviously it is not going to step up and step down simultaneously.

I mean if it is going to be used to step up 120v to 120/240v split phase will it also balance those legs?

Consider a 30amp 120v shore connection. Am I going to be stuck with 15amp on either leg. Or will the auto transformer also do what it does when it is in balancing mode while stepping up allowing 30 120v shore power to become 120/240v where 30amps could be pulled on either leg (so long as the combined simultaneous load of either leg does not exceed 30amp)?

Link to autotransformer:

Application: to determine if a system build will require more than one autotransformer. It's is my desire to design a flexible system for my RV so that I may power a 50amp service distribution box, with either 50amp shore power, 50amp service from my generator, my battery bank or 30amp 120v single phase from shore power. I am already intending to use an Autotransformer to balance the legs when using the batteries, the generator, or the 50amp shore power. The theory was that when needing to access 30amp shore power, I could connect my dual Multiplus 2 set up in parallel rather than split phase, feed in the 30amp 120v shore power, and feed the 120v output of the inverters into the same autotransformer I was using for balancing, have it instead step 120v up to 120/240v, send that along to my distribution box, and problem solved. At long last. Maximum flexibility. But if the auto transformer won't balance and step up this is not going to serve me too well. Being limited to 15amps on either leg won't do much good.

I do know the wiring to the auto transformer is different when you are stepping up 120v to 120/240v than when you are balancing a split phase input.

And that the wiring is different when running Multiplus 2 units in parallel than it is when running them in split phase.

The idea is hopefully to use a series of switches to switch between the two wiring configurations rather than having to spring for a second auto transformer.

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2 Answers
mvas avatar image
mvas answered ·

Yes, there are example Wiring Diagrams that will allow either a 120V 30A connection or a 240v 50A connection your AT, Quattro and Main Panel, as needed. No need to re-invent the wheel.

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snoobler avatar image
snoobler answered ·

Worth noting that the maximum current the AT can handle on N is 28A.

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