Inverter -- panel management

[sailingharry]

So, I am finally upgrading our 1998 Freedom 10 inverter with a fancy new Victron 3KW. And I have a philosophical dilemma.


The boat was originally built with an odd 120V panel setup. You could select "shore power" and it would have all circuits powered. Or "inverter" and only outlets powered. Power went from the shore inlet to the main panel, then to the inverter/charger, and then back to the main panel.


On the new inverter, I'm going to be more conventional. Shore inlet to inverter to panel. And this inverter can split the incoming power, with one as shore/inverter and one as shore only.



Our AC is fairly simple. Our inverter loads are outlets. Our non-inverter loads adds the hot water heater (and potentially future air conditioners).


So, here's the question. Do I use the split feed, and run the inverter to the inverter bus, and the 110V to the non-inverter bus, as Victron intended? This would make it idiot proof. Or do I combine the bus into one, and have it come from only the inverter/shore feed from the inverter? This would have the risk of accidentally having the inverter powering the hot water and/or the air -- but it would have the benefit of intentionally doing so! (say, with excess solar available, or running air while motoring).


I'm inclined to think that I'd notice if the air was running when on inverter! And we almost never turn on the HW anyway.


**********
And while I'm doing this electrical work, I've come across another question. In the years since the boat was built, 4 charge sources have been added (solar, wind, watt&sea, and a "world" battery charger for use in Europe). All of these are on the battery bus on the battery side of the switch. This allows the batteries to be kept charged even with the switch off. But it also defeats the idea that the switch "kills everything." I could easily reconfigure to move them all to the other side of the switch (wires would all reach, and there is space to do this). I would keep the alternators on the battery side, to protect diodes.


Thoughts on both of these questions?


Harry

[skipmac]

I have an older Victron inverter/charger and if I recall correctly there is only one AC output to the panel. If there is a second I didn't use it.

On my Multiplus, if the inverter section is switched off so the Victron is in charger only mode then the AC from the shore power just passes through the Victron to the panel. If not connected to shore power switch the Victron to ON and the inverter feeds the output to the panel through the same set of wires.

If the new model is different I would check to see if the inverter output will also work as a shore power pass through and use that output to your panel. That would allow shore power or inverter to feed AC with just the one connection.

[sailingharry]

Skip,


The new Multiplus is pretty slick.


Shore power comes in. The unit can be set to "Off", "Charge only," or "Invert."


The 120 comes in and is split. One leg is simply a pass through, and intended for loads that will never see the inverter. This is rated at 50A. The other leg is the traditional, like yours, where it provides shore power on pass through, or switches to inverter when shore is absent. It is rated at 50A on shore, or 3KW on invert. It also can "boost" weaker power (for instance, on my boat where I only have a 30A shore connection). This really is idiot proof, and on a bigger/more complex boat, probably makes a lot of sense.



I am tempted to wire it like yours, where it all goes to one switch, either shore power or inverter, and the operator makes the power choices.

[smac999]

You defiantly want all the loads going through the inverter. Either using the split or inverting the whole boat. That way the boost and charger claw back will work Corectly. As the inverter reads all incoming amps.

The old way of having part of the boat from shore and then feeding some through the inverter. These functions do not work correctly. As the inverter never knows the full draw from shore.

I sound still recommend going from inlet to panel main breaker to inverter back to panel. Because the main breaker on the ac panel should shut off the whole boat. Including the inverter charger.

[sailingharry]

Smac,

Your idea makes a lot of sense and would make the job easy for me (and require neither purchase nor installation of additional cabling!)

I already have a wire from the shore inlet to the main breaker, and a wire going from the panel down to the inverter, and a wire coming back, and a breaker titled inverter.

I could eliminate the split bus and make the main breaker do nothing the trip the power to the inverter. Then the wire that goes from the panel to the inverter would be the only thing served by that main breaker.

Finally the wire that comes to the inverter to the panel through another "main breaker" would feed all the loads.

How often does the easiest solution also make the most sense?

I would have to combine the split bus and somehow eliminate the interlock on the shore/inverter breakers (probably some sort of screw that holds that on). And then basically be done!

[Stu Jackson]

This discussion keeps referring to incoming shorepower and inverter. I understand the use of these words to mean "powered by either the I or SP."


Might it not be helpful to also include the action of the ATS in this discussion?

[rslifkin]

I sub-paneled mine for simplicity. Here's a picture of the panel (with labeling). In my case, I've got 2x 50A / 125V legs coming in. The inverter transfer switch input comes off the L1 panel main breaker. Anything labeled L1 is directly fed from the L1 main (panel mains are up higher in the panel and not visible in the picture). L1/Inverter circuits are fed through the inverter. L2 is independent and doesn't touch the inverter at all.

The way mine is laid out, anything that I'd never want to run from the inverter can't be powered from it, but everything I might want to run from it is on the L1/Inverter sub-panel. This way, I don't have to think about turning stuff like the water heater and start battery charger off, as they only get power from shore / generator but are cut off when we unplug or shut the gen down and the inverter kicks on making it all automatic.

[skipmac]

Originally Posted by sailingharry

Skip,


The new Multiplus is pretty slick.


Shore power comes in. The unit can be set to "Off", "Charge only," or "Invert."


The 120 comes in and is split. One leg is simply a pass through, and intended for loads that will never see the inverter. This is rated at 50A. The other leg is the traditional, like yours, where it provides shore power on pass through, or switches to inverter when shore is absent. It is rated at 50A on shore, or 3KW on invert. It also can "boost" weaker power (for instance, on my boat where I only have a 30A shore connection). This really is idiot proof, and on a bigger/more complex boat, probably makes a lot of sense.



I am tempted to wire it like yours, where it all goes to one switch, either shore power or inverter, and the operator makes the power choices.

It seems like they just added an extra pass through only output to the previous setup. That actually can be a good thing as it will prevent you from accidentally running a big AC load off the inverter and draining the batteries. Almost happened to me once.

An idea. Run both outputs from the Victron to a selector switch before the AC panel. With the selector you can choose pass through only or full function output to the panel AC input. Then you can run all the loads either way.

[skipmac]

Originally Posted by smac999

I sound still recommend going from inlet to panel main breaker to inverter back to panel. Because the main breaker on the ac panel should shut off the whole boat. Including the inverter charger.

Agree this is a good function. You can accomplish this with the Victron inverter remote panel. The switch on the remote has ON/OFF/Charger only. Switch to OFF kills all output from the inverter AC and DC, so no AC from inverter or shore power feeds to the boats AC panel.

[skipmac]

Originally Posted by Stu Jackson

This discussion keeps referring to incoming shorepower and inverter. I understand the use of these words to mean "powered by either the I or SP."


Might it not be helpful to also include the action of the ATS in this discussion?

ATS meaning Automatic Transfer Switch?

If so, this can be a problem if you lose shore power and the Victron is in ON mode. It will then take up the AC loads automatically and if you aren't aware, will drain your batteries. Can't recall but there may be some way to set an alarm if this happens.

[sailingharry]

Some more clarity on the Victron. It does have an ATS, and if set to "Invert" it will happily ATS all day long. I try and turn our inverter on and off as needed, but I'm not overly good at that. But I'm much better at not having anything that uses 120V on when not needed. A friend had the marina trip the breaker in a major storm (flooding) when he wasn't in town, and it flattened his batteries.


The second line of the Victron doesn't have an ATS -- it is basically a pass-through (but it is monitored by the load share system as mentioned.


Curious thought. Not an issue for me, as I'm adding a ELCI breaker at the inlet that will protect against overloads, but in theory, you could draw full shore power from each leg -- or double shore power from the input line.