Balancing output of two inverters

I have two Quattro 120/5000 wired and programmed as split phase 180/autodetect on my boat. This has been working ok but I have been having some problems while cooking of overloading L1 even with the genny on. From what I read it looked like if I installed a auto transformer it would balance the lines of the inverters. I installed the auto transformer as shown on the website. While inverting it seems to balance the loads perfectly. While connected to shore power or genny the output is now even more unbalanced then before, even negative amps on one off the lines.

Any insight will be greatly appreciated

Burl

How does your shore feed work?

3-phase 120° or 2-phase 180° ?

2 phase

Assuming you are talking North America split-phase power here.

When connected to shore power, the neutral of the auto transformer and the neutral of the utility grid transformer are effectively in parallel. The auto transformer is attempting to balance everything on that circuit! Generator should work fine though, that’s not making sense.

The autotransformer should not be used when on shore power.
But it will likely not be convenient to disconnect it.

I’ve chosen to switch my neutral, but that can be dangerous because an inadvertent floating neutral will destroy your 120v devices.

Rick thanks for the response, Would switching to a single 230v quattro and the autotransformer make it possible to balance my load on the inverter breaker?

Personally, I don’t think it is a good idea to use European 230V + autotransformers in North America. Electrically, you have to worry about the European Neutral being wired to live north american L2 power. So ground relays will be a a direct 120V short to ground if activated. Yes, it can be made to work safely, and Victron shows it as a possibility in the wiring diagrams. And it avoids having the North American Neutral shore power connected at all, so you wont have your existing problem.

Or, you could do the following. This is a hack, and would be considered non-standard by code.
Leave the autotransformer wired in as it is, but put a 30A breaker on the neutral where it comes out of the autotransformer. When you want balancing, engage the breaker.
Yes, it is a manual thing, but you never disconnect the shore power neutral, so there is no danger of a floating neutral destoying your devices.

Disclaimer: I’m not a boat or RV guy. I have a DIY home setup.