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Geoffrey Schwark avatar image
Geoffrey Schwark asked

Split phase with two 120v Quattros and 5500 onan genset 30 amp each leg in an Rv configuration

I have two quattros I am going to setup as primary and Secondary/slave. I believe my 5500 watt onan is split phase 180 degrees out for 120/240.

Do I need a transfer switch if the genset is connected to ac-1 input on both quattros?

I would like to wire the quattros with each leg from genset to each Quattro along with each leg from shore power to each Quattro.

just want to make sure the transfer switches in the quattros can handle the transfer between shore and genset without an external transfer switch…

thx for any input

split phase
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Geoffrey Schwark avatar image Geoffrey Schwark commented ·

Btw these are 5kw 120v quattros…

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Kevin Windrem answered ·

Yes, the Quatro transfer switch will work, in fact, that's how it is designed.

Connect which ever source you want to have priority to AC 1 In. When AC 1 is present, it will override AC 2 In.

In most RV situations, shore power goes to AC 1 In and generator goes to AC 2 In so that if shore power is present, it will take the load and the generator will stop. Connect the generator to AC 1 In in situations where you have "weak" shore/grid power.

One note: RVs in the US may often need to rely on single phase 30 amp shore power. This is NOT compatible with split-phase configuration of two Multis/Quatros even if you select floating phase. For some reason, the system rejects the power of the two legs are in phase.

The workaround for this is to reprogram the Quatros and reconfigure the wiring for parallel operation when using 30 amp 120 volt shore power then reverse everything for 50 amp 120/240. All wiring needs to comply with the "equal length" requirement. The outputs must also be paralleled!


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Geoffrey Schwark avatar image Geoffrey Schwark commented ·

Kevin,

thank you for the quick response. You brought up some good points…

I thought the quattros had enough electronics to sense one hot leg down from shore power and would compensate and have the batteries or genset take the other leg up when in split phase..

if I configure for parallel, then I’ll only have one leg anyway @ 50 amp from both quattros. Correct me if I’m wrong. It seems there must be a way or some device to allow 1 leg @30amp to keep the quattros in split phase…. Possibly a victron transfer switch.

thx again for any input…..

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arstegmeier avatar image arstegmeier commented ·
Would it be possible to elaborate or show a schematic on the workaround you mentioned at the end? Can’t get my system to charge and this is how I’m set up.
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Geoffrey Schwark avatar image
Geoffrey Schwark answered ·

Kevin, if I have two let’s say 30 amp legs from an rv pedestal. Will these legs need to be in split phase to my quattros in order for the ac inputs to sense voltage on each leg Properly?

if so, then I believe I can solve the single leg issue with a splitter cable connected to two separate 30 amp plugs/sources and if needed an electronic phase transformer for the two legs if not in split phase from the pedestal.

I just want to wire the quattros once and not worry about reconfiguring the wiring and split/parrallel configuration on the quattros..

thx for any input to clarify…

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Kevin Windrem avatar image Kevin Windrem commented ·

It's not recommended to connect to two different shore power connections because the neutrals would get tied together somewhere in your system. If the shore power is from GFCI, you'll trip them. It's also against electrical codes.

You could insure that all neutrals from the two sources remain separate, then you'd be OK.

If the two receptacles are in phase rather than 180 out, the Quatros may reject the shore power.

An autotransformer to make 120/240 split phase from 120 single phase is a possibility.

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