New inverter installation, connection to boat's AC panel, shore power connection

[Nor]

I'm planning installation of a new Victron inverter and was thinking to run the whole AC panel from the inverter. And connecting the shore power directly to the AC input of the inverter, to be only used when needed, as the solar/batteries should be sufficient most of the time.

I'll connect the inverter to the AC panel input where the generator is currently connected. The generator will also connect only directly to the inverter.
I will (obviously) not run the generator when the shore power is connected. Still do I need a switch between the generator and the shore power, so that the generator doesn't see any power on it's output (when it's not running)?

Do I need a isolation transformer for the shore power? The Victron manual says that it's required on boats. The Leopard 40 manual shows there is a galvanic isolator on the shore power input, is that sufficient instead of a isolation transformer?

Finally, the inverter will be placed close to the batteries close to the galley. As I'll be using an induction cooker and oven I'm thinking to add a separate outlet directly from the inverter by the galley (independent of the boats AC panel), as the AC panel is on the other side of the boat. Alternatively I'll need to stretch a new cable from the AC panel back to the galley (next to the inverter).
Any downsides of doing it this way?

Thanks for any input (in this early stage of planing)!

[Tin Tin]

Do you mean an Inverter/Charger like the Victron Multiplus or similar?

[Nor]

Originally Posted by Tin Tin

Do you mean an Inverter/Charger like the Victron Multiplus or similar?

Yes, a Multi RS 48 6000 actually, but basically a inverter/charger like Multiplus.

[sailingharry]

When I installed a new multiplus, I reconfigured my boat to be much like your intention. A couple of thoughts.

I took advantage of the fact that I was running a new wire from the inlet to the inverter to install a leakage breaker. I forget the exact name, but basically a gfci. Right next to the inlet, required under current abyc standards and a good idea.

You must make absolutely certain that the white wire on the shore power run never connects to the white wire bus in the boat distribution system. If you do, you will trip the new Marina power systems when you plug in. What happens is the inverter when running connects the neutral and ground together. When you plug into shore power that connection trips the leakage breakers.

Having all power go through the inverter and then to the panel has some nice upsides. As originally wired, my hot water heater was not available to connect to the inverter. Not that I want to do that much, but it is possible now.

Your inverter probably has a feature that mine has that is really nice. I can tell the inverter the maximum shore power load that I want to take. It will then supplement that with inverter power if necessary. I have been in a lot of places where shore power is a conventional 110 household outlet. I have a 100 ft 12 gauge extension cord that I then use. I have told my inverter to never draw more than 15 amps from shore power. Even when I'm on a real shore power connection, it keeps the loads on the cable down.

And isolation transformer is inexpensive piece of gear. It does provide benefits. But at least here in the US, it is not a requirement.

[Nor]

Originally Posted by sailingharry

You must make absolutely certain that the white wire on the shore power run never connects to the white wire bus in the boat distribution system. If you do, you will trip the new Marina power systems when you plug in. What happens is the inverter when running connects the neutral and ground together. When you plug into shore power that connection trips the leakage breakers.

Thanks for your input!
The white wire in USA is earth? I have a 230V system.

[SailingHarmonie]

Originally Posted by Nor

I'm planning installation of a new Victron inverter and was thinking to run the whole AC panel from the inverter. And connecting the shore power directly to the AC input of the inverter, to be only used when needed, as the solar/batteries should be sufficient most of the time.

I'll connect the inverter to the AC panel input where the generator is currently connected. The generator will also connect only directly to the inverter.
I will (obviously) not run the generator when the shore power is connected. Still do I need a switch between the generator and the shore power, so that the generator doesn't see any power on it's output (when it's not running)?

Do I need a isolation transformer for the shore power? The Victron manual says that it's required on boats. The Leopard 40 manual shows there is a galvanic isolator on the shore power input, is that sufficient instead of a isolation transformer?

Finally, the inverter will be placed close to the batteries close to the galley. As I'll be using an induction cooker and oven I'm thinking to add a separate outlet directly from the inverter by the galley (independent of the boats AC panel), as the AC panel is on the other side of the boat. Alternatively I'll need to stretch a new cable from the AC panel back to the galley (next to the inverter).
Any downsides of doing it this way?

Thanks for any input (in this early stage of planing)!

A galvanic isolator is a cheap substitute for an isolation transformer. You don't NEED an isolation transformer, but it is a far better solution to the problem of ground currents corroding your boat.

I would consider any boat that had shore power and a generator connected together without a foolproof transfer switch (either manual or automatic) a serious fire risk. I know you would never intentionally run the generator when connected to shore power, but... trust me stuff happens.

You might consider one of Victron's Quatro inverter/chargers that incorporate a transfer switch. You connect shore power and generator to separate inputs, and you can program the priority for each.

If you run a separate outlet to the galley, direct from the inverter, you have to be sure that you have all the wire properly protected by breakers based on the wire size. Also, be sure that your connections are proper. Simply stacking AC ring connectors one atop the other in high amperage circuits is not the best policy. In the event of an electrical fire on a boat, it is REALLY helpful to have a SINGLE point you go to to shut down power to everything.

Warning #1: When I am inspecting a boat and I see that shortcuts were taken because the shortcut was easier to install than doing it the right way, that is a HUGE red flag. If it was done once, it was likely done on every project that owner touched. Trust me, I have seen some very ugly ones!

Warning #2: If you have hull insurance with a US company, you have to be really careful about modifications to such critical systems. If you do something stupid (like skip the transfer switch), and have a totally unrelated problem (your boat floods, for example) your insurance company may be within their rights to deny your claim because you did not keep the boat in seaworthy condition as you promised to.

Based on the questions you are asking, I would strongly suggest that you have a marine electrician review your design and installation. Either that, or spend a LOT of time doing more homework on the proper installation of AC power on a boat.

[Nor]

Originally Posted by SailingHarmonie

A galvanic isolator is a cheap substitute for an isolation transformer. You don't NEED an isolation transformer, but it is a far better solution to the problem of ground currents corroding your boat.

I would consider any boat that had shore power and a generator connected together without a foolproof transfer switch (either manual or automatic) a serious fire risk. I know you would never intentionally run the generator when connected to shore power, but... trust me stuff happens.

You might consider one of Victron's Quatro inverter/chargers that incorporate a transfer switch. You connect shore power and generator to separate inputs, and you can program the priority for each.

If you run a separate outlet to the galley, direct from the inverter, you have to be sure that you have all the wire properly protected by breakers based on the wire size. Also, be sure that your connections are proper. Simply stacking AC ring connectors one atop the other in high amperage circuits is not the best policy. In the event of an electrical fire on a boat, it is REALLY helpful to have a SINGLE point you go to to shut down power to everything.

Warning #1: When I am inspecting a boat and I see that shortcuts were taken because the shortcut was easier to install than doing it the right way, that is a HUGE red flag. If it was done once, it was likely done on every project that owner touched. Trust me, I have seen some very ugly ones!

Warning #2: If you have hull insurance with a US company, you have to be really careful about modifications to such critical systems. If you do something stupid (like skip the transfer switch), and have a totally unrelated problem (your boat floods, for example) your insurance company may be within their rights to deny your claim because you did not keep the boat in seaworthy condition as you promised to.

Based on the questions you are asking, I would strongly suggest that you have a marine electrician review your design and installation. Either that, or spend a LOT of time doing more homework on the proper installation of AC power on a boat.

Thanks! I'm still early in the planning and will also get help from a electrician. But as I'm in Asia I won't trust only a local electrician, hopefullyI can get someone experienced with marine designs.

For the outlets by the galley, if you could chose would you consider it better/more organised to have it coming from the AC panel on the other side of the boat?
Or add a small panel with a new master fuse coming from the inverter just by the galley, and then to a fuse going to outlets to the galley, and another fuse for the wires going to the AC panel?

[SailingHarmonie]

Originally Posted by Nor

Thanks for your input!
The white wire in USA is earth? I have a 230V system.

The white wire in a US system is the neutral.

What is described by Nor would be a very messed up way of wiring. So he is right do not do that!

If your shore power connects to the inverter/charger, that is where it ends! Hot, neutral and ground. Having the inverter AC output and shore power ALSO both connected to the same panel would be a recipe for disaster.

[Nor]

Originally Posted by SailingHarmonie

The white wire in a US system is the neutral.

What is described by Nor would be a very messed up way of wiring. So he is right do not do that!

If your shore power connects to the inverter/charger, that is where it ends! Hot, neutral and ground. Having the inverter AC output and shore power ALSO both connected to the same panel would be a recipe for disaster.

I'm not sure I follow what part would be messed up. I wanted to connect the shore power to the inverter/charger only.

But I think I need to connect the earth from shore power via the galvanic isolator, before connecting to the inverter/charger?

[sailingharry]

Originally Posted by sailingharry

And isolation transformer is inexpensive piece of gear. It does provide benefits. But at least here in the US, it is not a requirement.

I just reread this line. It should read

"An isolation transformer is an expensive piece of gear."

If it was inexpensive, the whole discussion would be moot! LOL

You asked about white. Yes, in the US, white is earth. I tend to use colors rather than descriptions/names so that those not quite as familiar follow the point.

[sailingharry]

Originally Posted by SailingHarmonie

If your shore power connects to the inverter/charger, that is where it ends! Hot, neutral and ground. Having the inverter AC output and shore power ALSO both connected to the same panel would be a recipe for disaster.

I actually have both shore power and inverter in one panel. While it was largely driven by where the wires were put in the original build, I like it.

Shore power comes to the breaker panel and into a two-pole 30 amp breaker. It is an isolated breaker. It leaves that breaker and goes to the inverter charger. The output of the inverter charger comes back to the breaker panel through what serves as a main breaker. Another 30 amp breaker.

I can right at the breaker panel turn on and off shore power. I can also see if the shore power feed is live, and also if polarity is correct. Using the other breaker, I can power up and power down the main 120v panel. To truly power things down, I would need to open both breakers. I find it a very logical and centralized way to manage the panel.

Up thread I mentioned the ground leakage breaker. It is a 32 amp breaker, so should never trip on overcurrent. It is buried in a inconvenient location, and I don't actually use it. (While inconvenient, I could get to it in under 30 seconds if I chose to.)

I don't have a generator, but I agree that having the ability to have both the generator and shore power connected to the same panel is extremely dangerous and prone to accidents. They make suitable transfer/selector switches for that purpose.

[Uncle G]

There's lots of useful stuff here and elsewhere on their site:

SmartGauge Electronics - Isolation Transformers or Galvanic Isolator? 1/2

Written for UK 0-240V system, but much is also applicable to US boats.

[EmeraldCoastSailor]

One thing I learned when upgrading my travel trailer with Victron inverter/charger, solar, lithium, etc. was that the Victron unit has terrific pass through capability (with excellent control features that I don't need on my boat) but the unit has to be turned on. This didn't suite me for my boat as I don't use my inverter all the time. I like it cut off when not in use.

In both cases, I wired my AC-in to the inverter and then connect AC-out to AC panel that powers everything, leveraging pass through. In the trailer, the Victron is always on and the AC-in actually comes from a transfer switch that selects shore power or generator. Use case didn't seem logical for me to use Victron transfer capability but that might help you. Definitely connect to AC panel to power everything IMHO.

[Nor]

Should I connect the shore power after the "earth leakage" fuse in the schematic to a switch that can switch between shorepower and generator? Then going into inverter/charger's AC input.

[Madehn]

I have a high amperage rotary switch that allows me to select inverter 1 inverter2 shore or generator for AC power. True I cannot combine two sources but I really don’t want or need to. It is simple and means I don’t have a single point of failure for my AC power. ( I can turn both chargers on for 280 amps of charging if I want to. Simple and robust.