Quick electrical question, inv. to shore

dLj · 2025-05-12T16:25:50-0700

I'm sorry, I'm not understanding your question. Perhaps rephrase it? Is your inverter one of these small ones with like a 12v cigarette plug on one end?

dj

JoeWhite · 2025-05-12T16:35:05-0700

If your inverter has a built in relay, you can connect it's output into the house circuit breaker input. This will provide 110VAC to all the existing outlets. You must provide a switch to turn off the 110VAC charger. The coffe maker needs over 500 watts.
Or you can plug in a power strip to the inverter and use it that way.

JoeWhite · 2025-05-12T21:00:08-0700

You have plenty of watts, Fred. An inverter of that size usually has a relay that automatically disconnects the shore power and uses the house batteries to produce 110VAC. You can then connect the output of the inverter to the existing circuit breaker and use the existing electrical outlets.
If electricity is not your forte, you may consider asking for someone for help. But it is easily doable.
I would recommend running your engine while the coffee maker is on as your house batteries will deplete quickly.

Terry Cox · 2025-05-13T03:54:06-0700

Hi Fred. Our Freedom 25 Xantrex (2,500 watts) charger/inverter has an AC inout/output wired directly to all AC onboard outlets. That way shore power bypasses directly to these outlets, but switches to the inverter when not. I use the Link 1000 to manually select or turn on the inverter when I want AC while away from shore power. A marine electrician can help you set it up properly, if above your pay grade, like it is with me.

I'm assuming your house bank and starter battery are separate. How many amp hours does your house bank have? Some care here, because using the inverter to make coffee using your AC coffee maker can consume quite a few amp hours. It takes a lot of 12 VDC power to run a 120 VAC appliance. I always use our gas stove to make coffee/tea, etc. Much more efficient.

But then again, I'm now on a black cold coffee kick that I really enjoy. Never much cared for hot black coffee, but cold coffee, a different story. And it does not take any electricity, other than when grinding the beans. Just like making sun tea. Let it steep for a day in my coffee press, then chill in the fridge. Ice cold coffee/tea;: Yum!

dLj · 2025-05-13T05:23:25-0700

What inverter do you have? It's unusual for a 3Kv inverter to only have one outlet. I'm wondering if there are hard wire connections somewhere on the unit.

dj

colemj · 2025-05-13T05:30:28-0700

Which inverter do you have? I've never seen one that large that did not have wiring outputs in addition to the plug output.

If it does not have AC inputs, then it will not have a transfer switch. You would need to wire separate outlet circuits to it that are powered only by the inverter. These would need a breaker.

If it has AC inputs, then likely it has a transfer switch, and you can just connect it into your existing AC circuits.

Mark

Captain Larry-DH · 2025-05-13T07:11:42-0700

colemj said:
Which inverter do you have? I've never seen one that large that did not have wiring outputs in addition to the plug output.

If it does not have AC inputs, then it will not have a transfer switch. You would need to wire separate outlet circuits to it that are powered only by the inverter. These would need a breaker.

If it has AC inputs, then likely it has a transfer switch, and you can just connect it into your existing AC circuits.

Mark

This! If you don't have electrical knowledge, the only safe way to DIY is to plug in the shore power cord to the output of your inverter. That will send the AC output through the boat's shore power breakers and distribution wiring.
You probably need an adapter plug or cable to connect the inverter's output socket and shore power cord. The prongs are likely different.
Edit - if you post a picture of the shore power plug and inverter socket we could offer more specific advice.

Don S/V ILLusion · 2025-05-13T07:32:05-0700

Captain Larry-DH said:
… the only safe way to DIY is to plug in the shore power cord to the output of your inverter. That will send the AC output through the boat's shore power breakers and distribution wiring.
You probably need an adapter plug or cable to connect the inverter's output socket and shore power cord. The prongs are likely different.

PLEASE delete this recommendation. It is highly unsafe!

Using a cable with dual male connectors exposes the user to potentially lethal voltage.

Johann · 2025-05-13T08:09:34-0700

Don S/V ILLusion said:
PLEASE delete this recommendation. It is highly unsafe!

Using a cable with dual male connectors exposes the user to potentially lethal voltage.

He is saying plug the shore power cord (with a 30A to 15A adapter) into the inverter outlet. Similar to how you would plug into a portable generator. Nothing about a dual male cable. But if you were going to do that just running an extension cord would probably be better.

Heres the manual

https://xantrex.com/wp-content/uploads/2021/12/XPower_Inverter_3000_Install_Guide975-0556-01-01_Rev-A.pdf

looks like it does have a hardwired option.

Stu Jackson · 2025-05-13T08:49:30-0700

Johann said:
looks like it does have a hardwired option.

It does, but no automatic transfer switch. This will require Fred to install switches and develop an UNDERSTANDING of how boat electricity works, both AC and DC.

fred1diver said:
similar to house power to generator switch, but in a small package

Fred, you can't do this without manual switching and you MUST learn how to do so. You CANNOT have two sources of AC present at the same time.

dLj · 2025-05-13T09:08:48-0700

Stu Jackson said:
It does, but no automatic transfer switch. This will require Fred to install switches and develop an UNDERSTANDING of how boat electricity works, both AC and DC.

Fred, you can't do this without manual switching and you MUST learn how to do so. You CANNOT have two sources of AC present at the same time.

THIS!!!

A +1 is insufficient....

dj

Captain Larry-DH · 2025-05-13T10:34:07-0700

Don S/V ILLusion said:
PLEASE delete this recommendation. It is highly unsafe!

Using a cable with dual male connectors exposes the user to potentially lethal voltage.

That is NOT what I wrote. Read it again. My suggestion was not at all unsafe. Battery —> inverter —> shore power plug from boat is no more unsafe than plugging shore power plug into a dockside power pedestal or generator (with or without adapter for plug prong configuration if needed but NOT double-male “suicide“ adapter).

colemj · 2025-05-13T10:49:27-0700

Stu Jackson said:
It does, but no automatic transfer switch. This will require Fred to install switches and develop an UNDERSTANDING of how boat electricity works, both AC and DC.

Fred, you can't do this without manual switching and you MUST learn how to do so. You CANNOT have two sources of AC present at the same time.

He doesn't need any switches to do what he wants, and it is OK to have two sources of AC present at the same time - just not on the same outlet.

Since that inverter does not have AC input, he can install a separate outlet(s) where he wants them and wire them directly to the inverter, while the other outlets run off shore power.

Or he could do what Larry suggested, since his original post stated he didn't want to install outlets. This would give him whole-boat AC from the inverter.

Or like you suggest, he could install a manual switch that selects shore or inverter, but not both. This would also give him whole-boat AC.

Mark

Stu Jackson · 2025-05-13T16:20:53-0700

Mark,

My concern is that he may not be aware of the serious issues he faces simply because of the way he posed his questions. He appears to not be aware of Boat Electricity 101.

While you are correct in your comments, here are my concerns to your points:

1) Not on the same outlet..yes. He may not know that.

2) ...and said he didn't want to add outlets.

3) If he does, he NEEDS a transfer switch to ASSURE he doesn't have two sources of AC at the same time. He can't plug into shorepower when his inverter is on this way without a transfer switch.

4) Not "could" but MUST.

I am very concerned that he might not be aware of the safety and management issues.

colemj said:
1) He doesn't need any switches to do what he wants, and it is OK to have two sources of AC present at the same time - just not on the same outlet.

2) Since that inverter does not have AC input, he can install a separate outlet(s) where he wants them and wire them directly to the inverter, while the other outlets run off shore power.

3) Or he could do what Larry suggested, since his original post stated he didn't want to install outlets. This would give him whole-boat AC from the inverter.

4) Or like you suggest, he could install a manual switch that selects shore or inverter, but not both. This would also give him whole-boat AC.

Mark