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bibbjs asked

Two AC Systems with Two Multi Plus

So we have a sailboat with two separate 110VAC systems. They have separate plugs for shore power. One has a Multi-Plus 2000VA inverter feeding much of the system. We are installing a Multi-Plus 3000VA inverter on the second system. My question is that since BOTH systems can be fed from the onboard generator, if we leave the selector switches for both systems on the generator selection, is it possible to backfeed one system from the other? Can they get in a phase add situation and cause high voltage? Are there any other failure modes I am not thinking of?


MultiPlus Quattro Inverter Charger
2 |3000
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wkirby answered ·

The MultiPlus' will synchronise to the generator. Their backfeed relays will close and the generator power will feed through to the output of each MultiPlus. The output will be directly connected to the input and the MultiPlus will charge the battery. Both MultiPlus' will be in phase when the generator is running. They may drift out of phase from one another when the generator is not running and they are running from battery.
In standard configuration, the MultiPlus will not backfeed to the generator. When the generator is not running, the backfeed relay will open and it will not be possible for the inverter to backfeed.

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bibbjs avatar image bibbjs commented ·

I guess my concern is that one inverter would see the other inverter on the generator input line (generator off, but switched that way) and it could start a feedback loop. As you say, when the generator is on, then both inverters phase synch to the generator. When it is off, they will still see each other I think...

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