Inverter with shore power - Question ???

tpenfield

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Greetings,

My new-2-me boat, a 2016 Cruisers Yacht 338 Mid-cabin Bowrider has shore power and an inverter system. I am not sure how is all is supposed to work. I have an AC outlet in the cabin and another AC outlet in the head compartment.

It seems like the AC outlets want to run off the inverter system and not shore power. I also have 2 refrigerators on the boat that could run off of AC or DC. Of course running everything from the inverter system is power limiting and seemingly inefficient, if you have shore power available. The Owner's Manual is a bit vague on the inverter system, and I have not investigated too much.

I am just wondering what is the typical setup for a boat? Does all the the AC power have to come from the inverter? Or . . . should I be looking for some sort of a switch that allows AC directly from shore power? (when I'm connected to shore power)

Most of the AC stuff, I would want to use only when I am connected to shore power, and only use the inverter in a pinch.

I plan on installing a microwave oven in the cabin, and I'd like to get this inverter/shore power stuff figured out beforehand.

TIA for any guidance on these systems.
 

alldodge

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"IF" designed properly, everything should run off shore power and only run off the inverter when switched. Most Friges are 12VDC and 120AC and don't use an inverter
 

tpenfield

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"IF" designed properly, everything should run off shore power and only run off the inverter when switched. Most Friges are 12VDC and 120AC and don't use an inverter

Yes, that is also what I was thinking . . . just need to find a switch that does that :unsure:
 

alldodge

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Do the fridges have a AC and DC breakers?
Have seen some installed that only run on DC but still have a breaker
Oh and I have an additional shore power breaker next to the shore power connection
 

tpenfield

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Here are the panels (from the Owner's Manual, since I'm not near the boat right now). .
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IMG_2437 2.JPG
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IMG_2440 2.JPG
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It looks like both refrig's will run off 12 VDC, The Cockpit frig will run off shore p[ower and the cabin frig will run off the inverter.

It also looks like the 120VAC outlets (head & interior) and the microwave only run off the inverter. That seems like a lot of potential load on the inverter, depending on what you have turned on.

CY Tech Support sent me a diagram of the AC wiring, which shows the layout a bit different than the switch panel. So, I'll have to spend some more time with it and see if I can figure it out.
 

alldodge

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Wonder if they have it setup that way so it can be built cheaper :unsure: or may be an inverter/charger combo maybe

Does it have a galvanic isolator installed?

This is one I have which shows a combo unit which should do a pass thru when inverter isn't needed
 

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tpenfield

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Yes, once I have a chance to go through things more extensively, I may put on my 'electrical engineer's hat' and do some re-engineering of the system to better utilize shore power when it is available.

It sort of looks like an arbitrary split of the 2 systems.
 

Grub54891

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Did you try running the fridge and stuff with the breakers off at the inverter?
 

bruceb58

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Many inverters have a built in transfer switch. It makes the shore power the priority so that it basically bypasses the inverter function when shore power is live.

If your inverter does not have an internal transfer switch, there would likely be an external transfer switch. Follow the shore power cable and see where it goes to.
 

tpenfield

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Ted, have you called Cruisers customer service?
Yes, we are good friends now. 😛

As I look into the charging system . . . which is the Xantrex Freedom SW 2012 model (2000 watt/12 volt) . . . it may provide the type of functionality I'm looking for. There is a 'System Control Panel' , which is part of an 'Xanbus' system, which I'll have to figure out. There are a few more bits and pieces that I'll have to figure out, but it may do what I am expecting . . . i.e. use shore power when available.

It seems like every step of the way as I learn about the boat, I am downloading another manual to read through. My head is starting to hurt 🤪 :rolleyes:
 

Bob Sander

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I think the use of the inverter is an attempt to keep the shore power amperage in check.
If you get the hot water heater and both fridges, the mic... etc, all running on shore power, that's a lot of amps.
A battery charger on the other hand for intermittent charging is not a big amp eater. With the inverter setup, you can deliver a lot of amps for shorter periods and then charge the batteries off hours, all without running a cord the size of welding cables for shore power.

I think if you change that out you may run into under amperage problems at peak times.
 
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bruceb58

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Yes, we are good friends now. 😛

As I look into the charging system . . . which is the Xantrex Freedom SW 2012 model (2000 watt/12 volt) . . . it may provide the type of functionality I'm looking for. There is a 'System Control Panel' , which is part of an 'Xanbus' system, which I'll have to figure out. There are a few more bits and pieces that I'll have to figure out, but it may do what I am expecting . . . i.e. use shore power when available.

It seems like every step of the way as I learn about the boat, I am downloading another manual to read through. My head is starting to hurt 🤪 :rolleyes:
That has the builtin transfer switch I mentioned before.
 

tpenfield

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I'll have some more time to work with the electrical system this weekend . . . hoping to get it figured out. It does look like the system senses shore power and handles the source of AC accordingly.
 

tpenfield

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Quick update . . .

It appears that the inverter figures out what it needs to do and balances shore power with inverter power. I believe it also can charge the house batteries from shore power, as needed.

I am wanting to add solar power to the electrical system of the boat, since the boat will be sitting on a mooring during the summer, and it would be nice to maintain the batteries while the boat is not in use.

My plan is to buy a 100 watt 12v solar kit. mount the panel on the top of the radar arch and run the wiring down to the solar 'controller' (probably mounted somewhere easily accessible - maybe the cabin). Then use power diodes to isolate the power feed to each of the 3 (three) battery banks.

There are 3 battery banks, as mentioned, 2 batteries for the Port engine, 2 for the Starboard engine, and 3 batteries for the House power. So, there would be about 14 watts (max) of power to each battery (or about 1 amp).

While running, the engines charge the batteries (of course). The house batteries get re-charging from the Port engine, as per the schematic that is displayed in the engine compartment.

I am wondering if 100 watts is enough to maintain the batteries? It would seem so to me, since trickle chargers are much less current (just a few milliamps).

I have done a little bit of searching and not found too much in terms of examples, guidance, or "how-to's".

Thoughts/experiences welcome.

TIA.
 
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Grub54891

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Not sure if solar will keep up. I've seen a few at the marina, and if we have to move them sometimes the batts are low/dead. One has a wind charger propeller thing. It always is ok. Wind around here is fairly constant; cloud cover slows solar down a bit.
 

Scott Danforth

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Ted, have you looked at the flexible solar panels?

I have seen boat covers with them where the panels are over the windshield
 

tpenfield

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Ted, have you looked at the flexible solar panels?

I have seen boat covers with them where the panels are over the windshield
Yes, I've been quite flexible in my search for solar panels. 😁 My preference is to get a flexible type (I think they are called 'semi-flexible') as that will fit the slight curvature of the arch top.

I had a flex panel on my Catalina 22 sailboat to keep its battery charged way back when and it worked fine.

I've also considered solar charging during winter layup. Right now, I have the boat plugged in to AC power from the garage.
 

Bob Sander

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Quick update . . .

It appears that the inverter figures out what it needs to do and balances shore power with inverter power. I believe it also can charge the house batteries from shore power, as needed.

I am wanting to add solar power to the electrical system of the boat, since the boat will be sitting on a mooring during the summer, and it would be nice to maintain the batteries while the boat is not in use.

My plan is to buy a 100 watt 12v solar kit. mount the panel on the top of the radar arch and run the wiring down to the solar 'controller' (probably mounted somewhere easily accessible - maybe the cabin). Then use power diodes to isolate the power feed to each of the 3 (three) battery banks.

There are 3 battery banks, as mentioned, 2 batteries for the Port engine, 2 for the Starboard engine, and 3 batteries for the House power. So, there would be about 14 watts (max) of power to each battery (or about 1 amp).

While running, the engines charge the batteries (of course). The house batteries get re-charging from the Port engine, as per the schematic that is displayed in the engine compartment.

I am wondering if 100 watts is enough to maintain the batteries? It would seem so to me, since trickle chargers are much less current (just a few milliamps).

I have done a little bit of searching and not found too much in terms of examples, guidance, or "how-to's".

Thoughts/experiences welcome.

TIA.
100 watts isn't much and would be okay if you are only using it to charge, but one assumes you will have at least an auto bilge pump that will suck power when no one is around?

Do you not have a 24/7 shore power supply available?
 

tpenfield

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Solar1-PNG.PNG

Here is my handy work with a schematic - keep in mind that this is for maintaining the batteries only (think trickle charge) as the boat sits at the mooring.

It would need to maintain the 2 Mercathode systems and the radio keep-alive, and maybe 1 or 2 other things - God only knows what.

Assuming not at full power throughout the day, If I get an average of 50 watts for 12 hours per day = 600 watt hours (0.6 kwh)

Assuming 13.5 volts to charge the batteries = 44 amp-hours each day.
 
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