How do I handle 2 shore power inputs and a genset?

[blfinche]

I'm looking to add an inverter charger to my boat. I have a Victron Multiplus Compact 12 | 2000 | 80 - 50. The boat has 2 shore power connections and one is labeled for the air conditioner. The boat also has a generator. The shore power inputs are both 110V 30 amp connections. The generator is also 110V.

The AC panel has 2 switches. You can see them labeled SHORE and GEN and AIR COND and GEN. Ideally I would like to wire my shore power and my genset to the AC input on the Multiplus via a AC transfer switch. That way when I'm on shore power, genset, or batteries the Multiplus would give me AC when needed. This would be easy with only one shore power line, but with 2 I don't know what to do.



Any suggestions on wiring the 2 110v shore power to the Multiplus?

Is there a way to parallel the 2 shore power inputs?

Should I just wire the shore power and genset into the transfer switch and operate the AIR COND by manually flipping the switch and turning on the genset? I don't plan on using the air conditioner unless the genset is running, since it would probably drain my battery too quickly.

Thanks,

Bobby

[Jammer]

You can't wire the second AC input to the multiplus because it only has one input.

If I recall correctly some of Victorn's larger inverter do have two inputs and two internal transfer switches to deal with this situation.

You can't parallel the shore power inputs for a variety of reasons.

You can wire the air conditioner as you describe, or wire it (in general terms) wtih a transfer switch to select either the inverter output or the 2nd shore power. That would allow you the choices of operating the AC from either the inverter, the generator (via the inverter) or the 1st shore power outlet (also via the inverter). You would need suitable overcurrent protection for all components.

[s/v Jedi]

You have to choose an input for the Multiplus, see attached diagram where the three inputs are connected to a rotary selector switch.

If you need more power than one shore power connection can give, then I recommend to do what I did: convert one connection to a bigger one.

The first one at the top is a 120V 30A 3.6kW inlet with isolation transformer and the second one is a 120/240V 50A 12kW (which is massive) inlet with surge suppressor (Florida) and galvanic isolator.

And the third is the genset.

[rslifkin]

With a single Multiplus and 2 shore power legs, I'd plan to run one of the legs through the inverter and run the other directly to the panel. Then you have 1 side of the panel for inverter loads and the other for things you'd never want to run on the inverter (presumably the air conditioning).

[s/v Jedi]

Originally Posted by rslifkin

With a single Multiplus and 2 shore power legs, I'd plan to run one of the legs through the inverter and run the other directly to the panel. Then you have 1 side of the panel for inverter loads and the other for things you'd never want to run on the inverter (presumably the air conditioning).

So how to run air conditioning off inverter or even off the genset?

[rslifkin]

Originally Posted by s/v Jedi

So how to run air conditioning off inverter or even off the genset?

My suggestion presumes that you have at least some loads (such as A/C) that you don't ever want to run from the inverter. But looking at the panel in question, it appears that both panel legs can be transferred to generator power. So when both are transferred to generator power, 1 leg would go through the inverter, the other feeds directly from the generator.

[smac999]

The multi will go on shore power 1. After the shore / gen transfer switch on the panel. You said you want to add transfer switch. But it’s right in the picture…. You already have 2 transfer switches.

Shore 2 / gen stays separate as is. Feeding air con. You can not combine 2 shore plugs.

Shore 1, shore 2, inverter output neutrals must all stay separate.

Best done by someone who knows how to do it..,

[smac999]

Originally Posted by s/v Jedi

So how to run air conditioning off inverter or even off the genset?

Air con won’t run off inverter. It will run off gen when air con transfer is on gen.

If he wants both shore inlets inverted . He needs 2 inverters.

[s/v Jedi]

Originally Posted by smac999

Air con won’t run off inverter. It will run off gen when air con transfer is on gen.

If he wants both shore inlets inverted . He needs 2 inverters.

I see. We run A/C off the inverter but that only makes sense for boats with big solar arrays.

I would still prefer a larger shore power inlet. Even when shore only provides 3.6kW and your peak loads are above that, the Multiplus does PowerAssist so it will work fine with a good house battery

[rslifkin]

Originally Posted by s/v Jedi

I see. We run A/C off the inverter but that only makes sense for boats with big solar arrays.

I would still prefer a larger shore power inlet. Even when shore only provides 3.6kW and your peak loads are above that, the Multiplus does PowerAssist so it will work fine with a good house battery

Yeah, the game changes a bit when you get to bigger boats where your ability to fit more battery and solar grows faster than your power demands. On smaller boats, you'll often have a few loads that just aren't practical to run on inverter power, so splitting things up is no big deal.