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Anything wrong with feeding AC Output of Inverter directly into Shore Power Input?-gctid397749

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  • Guest
    Guest replied
    Sounds like it should work just as long as there is no charger in your inverter that will try to charge your batteries with it own power source. If it does it will at the least discharge your batteries pretty fast even if you are not watching TV.

    The reason the charger will kill the batteries is because it will not be 100% effecient so it will not be in an even loop so to speak.

    Be safe however you decide to do it.

    Leave a comment:


  • Guest
    Guest replied
    Our boat sits on a trailer 10 months of the year. No power, ever.

    When I first bought the inverter, it was for 1 reason only - so my wife could use the microwave oven. We do not spend nights on the hook. We use the boat only during the day.

    In it's simplicity - we have 2 batteries installed solely providing power to the inverter. That's it. And then we have the leads from the on board battery charger/alternator to charge those batteries.

    When I bring the boat home, I turn off ALL breakers (they are already all off, but I routinely do this again). I attach the shore power cable and plug it in. I then turn on the exterior AC breaker. I then go into the cabin - ensure I have AC at the main panel, and then flip on the AC Main breaker.

    Once I then ensure the AC meter is showing current, then I engage the battery charger.

    When we are ready to launch the boat, I do everything in reverse. I turn off all the individual breakers - I then turn off the AC Main. I then go outside on the transom and turn off the AC breaker. I then unplug the cord from the house.

    Now at this point - I NEVER touch the AC panel again - All AC breakers are off.

    When we want to use the microwave, we reach in under the cabinet, unplug the microwave from the "shore power" outlet, and plug it directly into the AC out of the inverter. Then we turn the inverter on.

    When we are done using the microwave, we turn the inverter off. Again, at no time do we ever go near the AC Main breaker panel, nor do I ever turn on the AC breaker in the transom locker. So even if someone accidentally bumped one of the cabin breakers "on" - there is no current coming into that panel.

    Now for that 1 time I might actually get around to spending enough time anchored away from shore power, I don't want to have an extension cord running inside the cabin (right in front of the steps) to go from the inverter to the galley to plug in the TV. IF I have a power cable already run from inside the boat through to the transom locker, then I would connect the cable to the shore power outlet. I would then go back into the cabin, ensure ALL breakers are off. Go back out to the transom, enable the AC breaker there. Then go back inside the cabin, ensure everything looks good on the panel, engage the AC Main breaker, and then engage only the Receptacle breaker.

    I understand there are "oops" moments - hell I just launched the boat yesterday and left the damn drain plug out - and then left the damn trim down when pulling out. But since we have been accustomed to not having any AC available to us for the last 3 years with this boat, I think for the most part for that 1 time we may want to watch TV while anchored - I think we'll be OK.

    Leave a comment:


  • Guest
    Guest replied
    I am not a Marine electrician by no means, but I have quite a bit of electrical experience with Gen sets and tranfer switches etc. I believe what you are wanting to do is simply plug your shore power cord into the inverter AC outlet.

    If so like some have mentioned you will need to make sure your battery charger(s) are turned off including any type of converter/charger built into your inverter if it has any. Also does your inverter have any type of a shore power sensor that would switch it or turn it off if it senses shore power?

    I think that what you want to do can be done safely. Depending how your system is done it may not be practical. Your system may have breakers that can be turned off so that only the wanted outlets are supplied power. Do you have any schematics or wiring diagrams of your system?

    Leave a comment:


  • Guest
    Guest replied
    I think there are always 2 ways to look at "do it yourself" projects.

    I for one don't want to ever take a short cut that eventually someone else can become the unsuspecting victim of my doing. I added a partition wall in my wife's old house - Yes, I could have run the electric myself - but I realized the fact that someday someone else was going to live in that house, and that's one liability I didn't want hanging over my head - we paid a certified electrician to do the work properly - or at least they take the liability off us.

    Now when it comes to modifications on the boat - everyone is going to have an opinion on how things can be done versus how things should be done. I really do appreciate everyone's feedback - that's of course the reason I post questions here - to educate myself - I don't know everything

    As my boat sits today, and with my personal life schedule - I don't have the ability/time to always do things the "correct" way - thngs like that take time. Absolutely putting in the switches, rerunning the wiring, etc etc is the right way to do it, and at some point in time, that is exactly what I will do - maybe over the winter when we are not able to take the boat out.

    But living in the Seattle area, where you only get 3 days of sunshine a year to take the boat out - do you really think that's the time to take on a project of that magnitude when running an extension cord can still SAFELY accomplish the same end goal?

    To me, it's never a question of not wanting to do it right - it's about juggling the time to do it. If I can SAFELY get through the summer with an extension cord running from the inverter directly into the shore power for the 1 night I may be on the boat using the TV - do you see where I'm coming from?

    I do appreciate the feedback for how things should be done the correct way - and when time allows, it certainly will be something I look into doing. Or then again, I may stick with my original thought - leave the TV disconnected so it can only be used while at dock. I haven't made that decision yet.

    Leave a comment:


  • 2850Bounty
    replied
    check737 wrote:
    ....... where as improper wiring in the AC panel could be quite dangerous.

    JMHO
    Goosh, I hope that no one took my comment as if to imply that "improper wiring" be done!

    .

    Leave a comment:


  • Guest
    Guest replied
    2850Bounty wrote:
    Question: What is it that's preventing you from installing a slide bar lock-out main breaker arrangement, and a bit of re-wiring?

    It would become Goof Proof!

    (where it says "Generator", would now say "Inverter")

    You know Rick not everyone is marine electrical qualified and it cost a lot of money $150 per hour up here to get things done.

    What is wrong to just use a TV or microwave connecting the inverter to the shorepower.

    It is safe and easy where as improper wiring in the AC panel could be quite dangerous.

    JMHO

    Leave a comment:


  • 2850Bounty
    replied
    Question: What is it that's preventing you from installing a slide bar lock-out main breaker arrangement, and a bit of re-wiring?

    It would become Goof Proof!

    (where it says "Generator", would now say "Inverter")


    Leave a comment:


  • Guest
    Guest replied
    Davidlyne wrote:
    If you are going to follow your precautions as listed, then it should be OK...IMO...

    Too many times we here after an incident when someone is hurt....Oh yeah, my mate does that all the time!!! That was the point I was making about what others do.
    I agree, good point.

    Leave a comment:


  • Davidlyne
    replied
    check737 wrote:
    No offence taken

    It is just to indicate it is an acceptable way to get AC into the panel just as connecting a portable generator is an acceptable connection.

    It does not mean a permanent connection with proper buss bar protection isn't the best way it only means it is not considered an unsafe way to connect an inverter.

    As with all procedures it is advisable to create a check list when connecting an inverter.

    IE. Trip all breakers that wont be used especially the battery charger/converter. Fridge should remain on DC.

    Do not use multiple appliances at the same time.

    No different than using a small generator.

    Some times we get too hung up on what is safe compared to what is expensive and not necessarily better.
    If you are going to follow your precautions as listed, then it should be OK...IMO...

    Too many times we here after an incident when someone is hurt....Oh yeah, my mate does that all the time!!! That was the point I was making about what others do.

    Leave a comment:


  • Guest
    Guest replied
    Davidlyne wrote:
    I don't want to offend anyone here, but when I read the comment, "it's done all the time" That really doesn't make it right!
    No offence taken

    It is just to indicate it is an acceptable way to get AC into the panel just as connecting a portable generator is an acceptable connection.

    It does not mean a permanent connection with proper buss bar protection isn't the best way it only means it is not considered an unsafe way to connect an inverter.

    As with all procedures it is advisable to create a check list when connecting an inverter.

    IE. Trip all breakers that wont be used especially the battery charger/converter. Fridge should remain on DC.

    Do not use multiple appliances at the same time.

    No different than using a small generator.

    Some times we get too hung up on what is safe compared to what is expensive and not necessarily better.

    Leave a comment:


  • Davidlyne
    replied
    I don't want to offend anyone here, but when I read the comment, "it's done all the time" That really doesn't make it right!

    Leave a comment:


  • 2850Bounty
    replied
    Do not turn the battery charger on you can't charge the batteries off the inverter.
    Good point, and all the more reason to set this up properly with either a Rotary Switch/Slide Bar L/O Main Breaker combination, or at minimum the Slide Bar L/O Main Breaker.

    I'm not quite sure if that part was understood earlier, but this would prevent unwanted circuits from being accidentally powered up during Inverter use.

    .

    Leave a comment:


  • Iproff
    replied
    check737 wrote:
    It is not a problem.

    It is done all the time.

    The inverter is self regulating and will trip if you draw too much power.
    I did exactly this on my 2755. Do not turn the battery charger on you can't charge the batteries off the inverter. You want to also be careful what you are running off the inverter nothing RED, that's nothing with a heating element.Does the new TV have a puck power cord it might be 12 vdc.

    Ken

    Leave a comment:


  • Guest
    Guest replied
    Robert K wrote:
    The inverter already exists inside the cabin, in the cabinet under the microwave. When we have shore power, the microwave is plugged into the existing AC receptacle. When we are without shore power, we plug the microwave directly into the AC outlet of the inverter.

    I recently purchased a TV for overnight slip use. Now I'm thinking what if we do want to use the TV when away from shore power. I don't want to run extension cords across the cabin.

    An immediate "lazy" approach I had (I really don't want to rip apart the boat, relocate the inverter, tap/splice into existing cabling, worry about isolators, relocating batteries, etc, etc.) And to address any questions that may come from this statement - the current installation of the inverter/dual batteries, etc was done professionally and properly - it has all the aforementioned proper requirements. I just don't want to redo all of it again to wire the inverter into the AC, since this will require relocating the inverter and everything else.

    Instead, what if I simply take a proper shore power cable and run it from the AC out of the inverter directly into the shore power connection?

    In my case, the shore power connection is inside the boat - exposure of any kind is not an issue - and I can easily feed a shore power cable from the inside of the boat to where the shore power connection exists today.

    The "advantage" I get here - I hope - is for the "simplicity" of running a single cable and 5 minutes of my time, I can now have AC power throughout the boat on all recepticles (just like I'm at the dock) by simply taking advantage of the existing AC breaker panel / shore power connections that are already on the boat.

    Is there something I'm not aware of that would make this a big "no- no"?

    And "no", I would NOT attempt to run the fridge on AC this way at all. Only the existing "receptacles" and "microwave" breakers from the AC Main panel would be turned on.
    It is not a problem.

    It is done all the time.

    The inverter is self regulating and will trip if you draw too much power.

    Leave a comment:


  • Guest
    Guest replied
    Rick,

    Thank you for all the valuable feedback - no offense is ever taken

    I'm sure one day I will take on the task of redoing the inverter such that it is cabled like you suggest - but it's good to know that "in a pinch" I could safely get away with running a cord until such time that I can do what you provided.

    Thanks again!

    Leave a comment:

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