Inverter for AC Power at Sea

[LostDog88]

Greetings:

I am attempting to design my own Solar system for not only keeping the battery bank charged, but hopefully to produce enough wind/solar to use devices through an inverter while on hook or at sea.

I have a pretty decent grasp on electricity and understand I will need to "math" out the AMPS System Voltage, etc, etc. Those questions will come later.

What I want to do is plug the inverter into the shore power plug and turn off the battery charger as there would be no need for it. Charging would come through the charge controller for wind/solar.

So.....first question. It reasonable to think I can plug at best a 20 AMP plug from the inverter to the shore power to "heat up" the AC plugs in the house? Or is there a better solution than what I am thinking?

Other that only having at best 20 AMP on a small gauge wire to a 30 AMP plug.........what am I missing? Or is this just a bad idea?

[Sailmonkey]

Your post makes me think your over complicating a simple thing.

You can plug a 50 watt inverter into the shore connector if you want, it’ll still send power to the outlets, but only 50 watts.

No problem.

Or spend some money and get an inverter with an automatic transfer switch and wire it to the outlets so that it’ll power them when shore power is gone.

[LostDog88]

Originally Posted by Sailmonkey

Or spend some money and get an inverter with an automatic transfer switch and wire it to the outlets so that it’ll power them when shore power is gone.

I probably am overthinking this.

Mostly because I may understand electricity but I don't understand the mechanics of boat wiring.

Please tell me more of this inverter with auto switching and maybe the basics on how it is wired.

I could go google. Which I will, but I want to know more than what is on a white paper.

I am designing a system so most likely I will need a new inverter anyway............

So, while I wait to hear more, off to the "Google's."

[LostDog88]

BTW. Thanks. This seems the same thing that is in my RV.

Easy Peasy. 'Preciate the help!

[Sailmonkey]

It’s a simple thing, the inverter is inline between the power supply and the outlets. When there is shore power it is preferred, and is passed through. When there is no shore power the inverter pulls from the batteries and supplies the outlets.

Most of the inverters with the pass through (that I can pull off the top of my head) also act as battery chargers.

[LostDog88]

Originally Posted by Sailmonkey

It’s a simple thing, the inverter is inline between the power supply and the outlets. When there is shore power it is preferred, and is passed through. When there is no shore power the inverter pulls from the batteries and supplies the outlets.

Most of the inverters with the pass through (that I can pull off the top of my head) also act as battery chargers.

Yes. Thank you. A Quick google and I found lots of options.

Now for the final design phase is to determine my AH usage and battery bank configuration.

Thanks for the help folks.

[endlesspursuit]

Purchase a blue seas switch for shore / off /gen or in your case inverter. Wire the inverter to the gen side and shore to the shore side. Then wire switch to point that your shore power connects to now. Very simple and now you have manual control. I just did this on my boat with a non pass thru inverter and it works perfectly and very simple. Plus there is no way to back feed shore power to your inverter by mistake.

[Dave22q]

Why not let your inverter connect to your batteries? On shore power the batteries will continue to be charged. Unless your inverter pulls more than your charger can feed there should be no problem. The same applies at sea or on the hook, you simply need to know how many hours of A/C can be used given what you are getting from wind/solar/etc.

[Maclir]

Why not have everything 12Volt? why do you need AC?

[LostDog88]

Originally Posted by Maclir

Why not have everything 12Volt? why do you need AC?

Laptop. Cell Phone Charger. Ice Maker. Just a few of the reasons to keep the wife a happy soul on board.

If I can do it, why not?

[Maclir]

Laptop and cell phone can use 12 Volt charger. Who needs ice?

[EarlWer]

Originally Posted by Maclir

Laptop and cell phone can use 12 Volt charger. Who needs ice?

Laptops use a variety of voltages. Most are not 12V

Cell phones use 5V, which is standard for USB.

Granted, 12V DC to 115V AC (inverter) back to 5V or Laptop voltage is inefficient, but how do you supply power to all those misc. items that use 115V?

[LostDog88]

Originally Posted by Maclir

Laptop and cell phone can use 12 Volt charger. Who needs ice?

You are correct. How about "because I want it that way?"

I can use everything on DC if I wanted to. But since I am planning on putting in solar/wind and an inverter capable of using AC, why not use it.

As for who needs ice. I need ice. I want ice. I require ice.

LOL.

Therefore the original question is valid and is not needing to be redesigned.

I want AC on my boat to power AC devices. And I want it done correctly. Therefore the original question stands.

The auto transfer or manual transfer switch seems to be the best idea and the simplest. Probably the route I will go.



:-)

[rfinklegal]

If you want to connect an inverter into your hardwired AC system (as opposed to just using the receptacle(s) on the inverter, to not void the warranty you will need one which allows the hard wiring. My research showed that all of those have automatic transfer switches. If you want to use a laptop, you will need to get a pure sine wave inverter (more expensive than modified sine wave). Then you need to calculate to wattage size of inverter (1000, 2000 or 3000 watts etc.). If you want to power a microwave, you should get at least a 1500-2000 watt (continuous) inverter.

I wired mine between the batteries and the AC panel, with a separate charger. I had an inverter/charger on our prior boat. Those have the shore power running through them. The problem was the unit died when it was hot, so we went to a marina to plug in and run the air conditioning... When the unit died there, we had no AC at all, and thus no air conditioning. That is why we got a charger and separate inverter - air conditioning not reliant on either.

[wingssail]

Originally Posted by Maclir

Why not have everything 12Volt? why do you need AC?

We thought this 35 years ago, and started to equip our boat that way, but it became difficult to find appliances which ran off of 12 volts, and what was the point?

So we wired our boat with AC outlets, three of them, and installed an inverter.

From that point forward we take AC for granted. We use whatever we want on the boat, 12volt or 110AC. On shore power the inverter passes it through to the outlets AND charges the batteries. When shore power is removed the Inverter uses 12volts from the batteries and supplies the AC. Any other charging sources feed directly to the batteries.

It is all automatic and works perfectly.