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Managing Shore Power, and avoiding nuisance breaker trips.

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    Managing Shore Power, and avoiding nuisance breaker trips.

    One of the biggest challenges of living on a boat is avoiding nuisance tripping of your shore power connection.

    You’ll just be happy, enjoying life and then you put a muffin in the microwave and your shore power trips. Or you want a cup of coffee, or you turn on a hair dryer, or you do almost anything and your shore power trips. Lets try to solve that problem.

    It’s going to sound redundant but the easiest way to avoid shore power nuisance tripping is to get a larger shore power connection. That is easier said than done, but it does not hurt to ask your harbormaster if you are in a long term slip. That’s what I did, and when the harbormaster declined because of the cost I offered to pay for the upgrade myself. That worked and it got me a 50 amp 120 volt connection plus my existing 30 amp connection. The cost was a few hundred dollars but well worth it because I was in the slip for the long term. Adding shore power capacity might be a good idea for someone with an agreeable harbormaster that is tied to a permanent slip, but it is not an option for everyone though.

    Another method is to use a little known feature of some high end inverter/chargers. If your inverter/charger has a setting for shore power size that will often do more than you might think. What the feature does is limit the amount of current into the inverter/charger by utilizing your house batteries as needed to assist in supplying the loads. For example if you set the inverter/charger to 5 amps shore power and then run your 1000 watt microwave the unit will draw some of the power needed from the ac input, and the rest from your batteries. When the microwave turns off the charger function will top off your house batteries, replacing the power used.

    This feature can come in extremely handy if you create a “inverter sub panel” on your boat and move most of your household loads to while leaving some large loads like your water heater on your main 30 amp shore power feed. That way you can use your household loads at will without overloading your shore power connection.
    If you have a larger boat you could theoretically have more than one inverter/charger feeding separate panels, both tied to one 30 amp shore power connection, allowing up to 7,000 watts of energy when you need it.

    Managing shore power connections is a constant challenge for a liveaboard. I hope this gives some insight as to the options available, and helps a fellow boater.
    Please share any ideas you have, and tricks you use to manage your shore power. Working together we can all learn from each other.

    KEVIN SANDERS
    4788 LISAS WAY - SEWARD ALASKA
    where are we right now​​​​​​???​

    https://share.findmespot.com/shared/...j23OquWOj2N3Xe

    #2
    While I don't use marinas, I've been told, most are adding 240v, 50 amp sockets.
    All my power runs thru my inverter (Magnum MS-PAE) and I think it's a great system. The inverters can be ganged to provide 16kw if you have enough battery power. The inverter powers the main AC power panel. If shore power fails, the inverter goes to battery, and if the batteries get low it starts one of the generators. All w/o a power interruption in the boat. Whenever the inverter isn't supplying AC power, it charges the batteries. I have enough batteries to run 2 days or more at anchor. I have 48v inverter banks. I have a private dock with 50 amp, 240v shore power and that's been enough. When I bought the boat it had an inverter panel and a too small 12v inverter. It was a pain. Now that inverter is an emergency backup. I went with 48v inverter banks because I can run smaller battery cables and I can have banks far from the inverter so the battery weight is somewhere it's needed.
    I can run anything on the boat with the Magnum inverter, but rarely have the water heater on. My diesel stove also heats the water heater. When a generator is running I turn on the water heater and usually make water. I try to have at least a 50% load on the generator so I don't glaze the cylinders.
    One of the biggest power problems for living aboard in cold climates is heating. Most yachts are short on wiring capacity for running several portable electric heaters. They often burn out plugin sockets and sometimes burn wiring if the breaker is too big. While I rarely heat with AC power, I changed all my 120v AC wiring to 10 gauge and the sockets for ones rated for 20 amps. So each circuit can handle 2 portable heaters. I've found electric heat is cheaper than diesel, but wood or wood pellets are cheaper than electricity. That's in an area that has power at .074/kwh. I got the pellet stove when diesel was $4 a gallon.

    Comment


      #3
      On my last boat I had a Trace SW2512 inverter charger. It was a complete power manager. I could program it to not take more than 25 amps. This left me a safety margin for continuous draw issues. It was a pure sine wave unit so everything ran correctly. If I needed more power it went to the batteries to get it. If batteries were low it started the gen. If the generator had over capacity it would send the excess power back to the shore, driving my meter backwards. It essentially turned my 30a shore cord into a temporary 50a setup. So in the morning house is 6a, hot water 11a, hairdryer 11a, microwave 11a, that’s 37a, 25 from shore and 12 from the battery but only while the microwave was on.

      sadly they don’t make it any more. I want one for my new boat. My new boat is 50v 125/250a and is well balanced so I never trip the shore breaker. However, I still want to upgrade my current setup. So what are you guys using that performs like this and what do you think of it?

      My boat splits the power needs. Heat, washer/dryer, AC heat pumps on one side and everything else is on the house side. Everything but the hot water on the house side runs through the inverter.

      i think we should start a new thread for addressing heaters.
      Azzurra
      Seattle, WA
      Ocean Alexander 54

      Comment


        #4
        Ok, you guys got me all reved up and I went off researching. I have discovered that Outback makes a power manager. Part number VFXR2812M, it does everything my old Trace unit could only it does it better. In other words, 2800watts instead of 2500 and battery charging at 125a instead of 100a. Price is $1900, less than I would have thought. I see old trace units selling for $1500.

        Now this unit may be over kill for most boaters. It however can add a lot of convince to the liveaboard life. The unit is capable of working in parallel with the grid or it can work in support of the grid(support means it kicks in when the grid power is lost). For those of you with or who want big solar panels, the VFXR series can manage solar along with a generator and grid to give you the most cost effective solution.

        there may be other manufacturers with similar products, I just haven’t discovered them yet.
        Azzurra
        Seattle, WA
        Ocean Alexander 54

        Comment


          #5
          Ok, I have now read the Magnum MS2812 operation/installation manual and I see that it equivalent to the Outback unit. What’s better, MS2812 is only $1500.
          Azzurra
          Seattle, WA
          Ocean Alexander 54

          Comment


            #6
            To throw another twist on things, the Xantrex SW series does exactly what I mentioned and more!

            For example you can put two of them together (with a single control panel) and get either extra amperage, or 240 volts, or full redundnace in case of failure.

            The 3,000 watt unit is rated at 4,000 watts for 5 seconds as a motor starting surge.

            Thats what I’ve had since 2011 a Xantrex SW12-3000 Big heavy beast. Something like 75 or 80 pounds. Love it!

            KEVIN SANDERS
            4788 LISAS WAY - SEWARD ALASKA
            where are we right now​​​​​​???​

            https://share.findmespot.com/shared/...j23OquWOj2N3Xe

            Comment


              #7
              Not trying to start an argument. Xantrex offers the SW3000. They only list 3 modes, inverter, charging, power share. Power Share is were it shares the AC input between the house and charging. So far I am unable to find a mode were it will take power from the batteries to supplement the AC input. Such as taking 30a from shore and 10a from batteries to provide 40a to the house.

              I know trace Trace was bought by Xantrex. I know they used to do this. They used to call it support mode. I cant find any documentation that they still do it. I could clearly be missing something, wouldn’t be the first time.

              For now I am only able to recomend the Magnum hybrid models MSH300 if some one is looking for this mode. Note, I have never used a Magnum inverter but it is the most common installation I see currently and supports everything Kevin pointed out in his first post.

              Kevin, if you see something I am missing please point it out.

              Azzurra
              Seattle, WA
              Ocean Alexander 54

              Comment


                #8
                Originally posted by Tiltrider1 View Post
                Not trying to start an argument. Xantrex offers the SW3000. They only list 3 modes, inverter, charging, power share. Power Share is were it shares the AC input between the house and charging. So far I am unable to find a mode were it will take power from the batteries to supplement the AC input. Such as taking 30a from shore and 10a from batteries to provide 40a to the house.

                I know trace Trace was bought by Xantrex. I know they used to do this. They used to call it support mode. I cant find any documentation that they still do it. I could clearly be missing something, wouldn’t be the first time.

                For now I am only able to recomend the Magnum hybrid models MSH300 if some one is looking for this mode. Note, I have never used a Magnum inverter but it is the most common installation I see currently and supports everything Kevin pointed out in his first post.

                Kevin, if you see something I am missing please point it out.
                The SW series will do exactly that. I have that model and if you set shore power to x amps it will supliment any loads with battery to keep the AC input amps below that number.

                Perhaps it’s not a listed feature but it works that way. I was too happy to figure it out. If memory serves correctly I thought or assumed it was for battery charging only until I tested it out. Set the unit for 5 amps and plugged in my heat gun and turned on the microwave. Batteries went to discharge and my Xantrex SOC meter went into alarm. AC input stayed at 5 amps. Again I was extremely happy to figure this out as it is a wonderful feature.

                The SW series is like the old Trace inverters. Big, heavy, reliable. Good units. Some of their low end, lightweight inverters are junk in my opinion, but the SW series is really good. I like the redundancy feature and am planning on adding a second unit as a backup.

                KEVIN SANDERS
                4788 LISAS WAY - SEWARD ALASKA
                where are we right now​​​​​​???​

                https://share.findmespot.com/shared/...j23OquWOj2N3Xe

                Comment


                  #9
                  Got it. They don’t really talk about it in their documentation. I even stopped at their both at the boat show, their rep was pretty ignorant about the capabilities of the unit. He referred to it as the freedom 3000 and spouted on about how it came from the Heart line. Heart Freedom line was a fine inverter charger in the early 90’s. It just never compared with the Trace line. I see the part number starts with SW. This was the Trace designation for their power manager line. So now I have discovered 3 units that truly power manage.
                  Azzurra
                  Seattle, WA
                  Ocean Alexander 54

                  Comment


                    #10
                    Originally posted by Tiltrider1 View Post
                    Got it. They don’t really talk about it in their documentation. I even stopped at their both at the boat show, their rep was pretty ignorant about the capabilities of the unit. He referred to it as the freedom 3000 and spouted on about how it came from the Heart line. Heart Freedom line was a fine inverter charger in the early 90’s. It just never compared with the Trace line. I see the part number starts with SW. This was the Trace designation for their power manager line. So now I have discovered 3 units that truly power manage.
                    Yes, I discovered it kinda by accident. Great feature, one that people I think overlook as a solution to the 30A shore power challenge.

                    KEVIN SANDERS
                    4788 LISAS WAY - SEWARD ALASKA
                    where are we right now​​​​​​???​

                    https://share.findmespot.com/shared/...j23OquWOj2N3Xe

                    Comment


                      #11
                      Check out ebay. Many of the units discussed here are much cheaper from dealers that use ebay.

                      Comment

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