Do you really need an inverter?

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islandtimecruiser said:
Just the other day we were on the hook and when I switched from generator to inverter I forgot to turn off the battery charger and water heater.
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For Flywright & Moonstruck:
It would appear that I am not the only one wired like that. (I'm looking in to changing it, though.)
 
My refrigerator is AC only so an inverter is a must. I bought a xantrex 1800 many boat years ago and built my house bank with 6V golf cart batteries. I hated hauling 8D's in and out of the engine room, out the door, on the deck and finally over the rail and down to the finger that floats beside my boat. Besides I get more usable amps from 2 6v than 1 8D. Also, the 8D's dont last long at all and the 6V's I have are now 10 years old. I would have had 3 8D's in 10 years.

Most generators have a modified sine wave, my inverter doesn't. It's a true sine wave and there is no damage to electric motors or electronic appliances like a modified wave can harm and it's quiet.

I anchor out and moor and in the moorings we can always hear the generators running and smell the exhaust. I really like the inverter for all the advantages I said.

I paid 75.00 ea for 6 batteries and about a grand for the inverter. I can't agree with your numbers.
 
islandtimecruiser said:
Just the other day we were on the hook and when I switched from generator to inverter I forgot to turn off the battery charger ad water heater. It tripped the breaker in the inverter. I have to be more careful next time.
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The previous owner of ours wired our AC system pretty cleverly. Our Shore Power runs through our inverter and is auto-switching. Our generator runs through the inverter and is auto-switching. Both Shore Power and Generator run through the Shore Power Selector before the inverter. The Inverter is hardwired to the breakers to only the fridge, and two outlets. Everything else is fed from the Shore Power Selector (Genny or Shore).

It seemed complicated at first, but if I lose power, I can have auto fall-back to an inverter. As I leave the dock, I shift to Ships Power and the inverter takes up the load. When I get onto a moorage, I started the genset and the inverter drops out.

It provides completely uninterrupted AC in any situation and we're never worrying about switches or breakers.
 
Ideally, an inverter should be fed from the panel via its own set of circuit breakers, then a sub panel follows with the inverter-driven circuits on it. Eliminates the confusion noted above. Being wired this way, auto pass throughs any external source be it generator or shore power. You can install an inverter by pass switch in case you have to pull it for service though in my case I could rewire the panel pretty quickly to accomplish the same thing.

My Magnum will accept both legs of a 50 amp circuit and pass two out if you like. So I have two sub panels which frankly wasn't necessary but "nice to have" After all a 4000w inverter is just a little over 30 amps allowing for the efficiency factor.
 
caltexflanc said:
Ideally, an inverter should be fed from the panel via its own set of circuit breakers, then a sub panel follows with the inverter-driven circuits on it. Eliminates the confusion noted above.
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I dunno. I find it quite handy. Everything has breakers. Even the wife understands how to shift power and it's impossible to get stuff on the inverter circuit that would overload it.

I would need a larger inverter to hold the entire boat up on AC in your example.
 
a normaly day

08.00 in the morning after breakfast we turn off the nightgen and going to the beach. Approx 11.30 we start the 15 KW gen and we can cooking and make agua and wash with the washmachine. After siesta we turn off for 4 hours the gen and we relax on the fly or on the beach.
18.30 we start the 15 KW gen for cook .
Approx 2100 hour we change the gen and start the 8KW nightgen and turn off the other morning.
And so we need aprox 8 hours/ day the inverter for freezer, fridg and other consum.
Underway we go without gen and the inverter is working with the inverter-Batterie-group from 3 X 8 D.
_________________________
Norbert
 
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islandtimecruiser said:
................... Just the other day we were on the hook and when I switched from generator to inverter I forgot to turn off the battery charger ad water heater. It tripped the breaker in the inverter. I have to be more careful next time.
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You might consider some rewiring so the inverter only powers the AC receptacles. With a proper transfer switch, everything can be automatic.
 
caltexflanc said:
Ideally, an inverter should be fed from the panel via its own set of circuit breakers, .............
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Because of the large DC current and the potential voltage drop, the inverter is usually fed directly from the battery bank or a battery selector switch. Of course, it should have properly placed circuit protection (a fuse or circuit breaker)
 
Panel Switch for Shore Power, Gen, Inverter

To easily run items off the inverter. I just replaced my 3 postion selector switch with a 4 postion switch from Newmar. You can select from Shore Power, Gen set, Inverter or Off. Before selecting inverter on the switch I turn off the breakers for the Batt. Charger, Water Heater and A/C units. $88.99 from Boatersland.com Works great!! :thumb:
Newmar SS 3.0 Transfer Switch*-*Newmar*SSSWITCH30 - AC Circuit Panels - Electrical Parts - Electrical - Boatersland Marine
 
SomeSailor said:
I dunno. I find it quite handy. Everything has breakers. Even the wife understands how to shift power and it's impossible to get stuff on the inverter circuit that would overload it.

I would need a larger inverter to hold the entire boat up on AC in your example.
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You misunderstood my post completely. Sorry for the confusion. By "sub panel", that is a CB panel fed by the inverter for those circuits that it is allowed to power. Not anywhere near all the circuits on the boat whatsoever. In fact, the inverter is a component on one of three different AC panels on the boat. The items on those panels do not interact with the inverter in anyway, nor do other components on the panel the inverter is wired to only those on the inverters sub-panel. Power transfer is completely seamless and automatic to the circuits served by the inverter regardless of source and requires no user intervention at all. Maybe when I get home I will snap a pic and 'splain better.
 
supertramp said:
08.00 in the morning after breakfast we turn off the nightgen and going to the beach. Approx 11.30 we start the 15 KW gen and we can cooking and make agua and wash with the washmachine. After siesta we turn off for 4 hours the gen and we relax on the fly or on the beach.
18.30 we start the 15 KW gen for cook .
Approx 2100 hour we change the gen and start the 8KW nightgen and turn off the other morning.
And so we need aprox 8 hours/ day the inverter for freezer, fridg and other consum.
Underway we go without gen and the inverter is working with the inverter-Batterie-group from 3 X 8 D.
_________________________
Norbert
Click to expand...

You are living the good life Norbert.
 
Why would I need all of that? The circuits are fed the same regardless of how the AC comes in. Each is protected on a labeled breaker and the output of the inverter is also protected by an independent breaker. The same goes for the genset. If I had a subpanel for the inverter using your logic I would need another for the genset.

I think that's overly cautious considering how well the system I have now is working.
 
SomeSailor said:
Why would I need all of that? The circuits are fed the same regardless of how the AC comes in. Each is protected on a labeled breaker and the output of the inverter is also protected by an independent breaker. The same goes for the genset. If I had a subpanel for the inverter using your logic I would need another for the genset.

I think that's overly cautious considering how well the system I have now is working.
Click to expand...

I am obviously confusing you because you are completely misunderstanding how the system is laid out. So once again, apologies. It may also be due somewhat to the greater size of my boat and the attendant greater number of electrical circuits. I'll be back home in a few days, maybe a picture or two will make it easy to explain. Again, please keep in mind in my case there are only about a half dozen circuits out of many that are being powered by the inverter. Are you powering every AC circuit on your boat with the inverter?

Edit: in the meantime, here is Magnum's installation and owners manual, which has some relevant diagrams. I have an MS4024, just FYI.

http://www.magnumenergy.com/Literature/Manuals/Inverters/64-0007 Rev D (MS Series)_Web.pdf
 
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No. I am not feeding all circuits with the inverter. It feeds the fridge and three wall outlets. Everything else is cold. If i start the genset (feeding THROUGH the inverter) those are fed by the genset... and the others go hot as well.

It's all irrelevant on shore power as everything is switched over by the transfer switch. I really see no need for another panel. Every AC load is protected and isolated by breakers in every possible configuration.
 
Headed out, but before i go, so where are the breakers for the fridge and three wall outlets and how are they connected to the inverter?
 
On the main AC panel where they've always been. It doesn't care where the AC comes from.

The fridge and AC outlets are fed from and through the inverter. Everything else is fed around the inverter and are only supplied with AC when the genset is on.
 
swampu said:
--To the subject, do you really need a large house bank with inverter and so on......
Thanks Paul
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Simple answer - yes. It simplifies onboard life and adds to the comfort of PNW cruising when away from the dock for weeks on end. While you're at it add a reliable genset too.

Norbert does it right. If you really want to save money sell the boat. Nuf said
 
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SomeSailor said:
On the main AC panel where they've always been. It doesn't care where the AC comes from.

The fridge and AC outlets are fed from and through the inverter. Everything else is fed around the inverter and are only supplied with AC when the genset is on.
Click to expand...

My boat is wired like this. Ac panel has six switches. Only two are connected to the inverter. When no shore power or generator ONLY those two switches can be powered. Period. Doesn't matter what switches are "on," only two are wired to the inverter.
 
Sounds like many panels I have seen...I guess without seeing it.

The main panel bus has been split...which make part of it a sub panel (in other words)that's connected up when the transer switch is on.
 
sunchaser said:
Simple answer - yes. It simplifies onboard life and adds to the comfort of PNW cruising when away from the dock for weeks on end. While you're at it add a reliable genset too.

Norbert does it right. If you really want to save money sell the boat. Nuf said
Click to expand...
Maybe I should have added more environmental details in my question.
1. Boat will be used primarily in the summer on the coast of South Mississippi, it gets very hot here. So the a/c will most likely run a good portion of the time.
2. Boat will be used about 60% of the time as a "mother ship" to support little boat fishing Trout, Snapper, triple tail or whatever we are going to catch and will be running a #400 ice machine to keep food, beer and said fish cold.
3. I have two 12.5kw gensets, although they haven't proven themselves reliable they do run and make water and power. Only time will tell if they are reliable.
4. The inverter, in my case, would only run games, tv, coffee maker or any other devices while the genset is off.

My question would be do you really need an inverter system at the expense of delaying the use of the boat that would function by just using generated power.
Your right about selling the boat to save money.....
 
I wouldn't leave home without a good inverter system. we anchor out 99% of the time and run the generator only about 1-2 hours a day. We really like the quiet. I currently run 1 large home refrigerator, wine cooler, tv system, micro wave , coffee maker, misc 110 lighting, and 2 navigation computer systems. I installed 2- 2KW outbacks wired in series to give me 4 KW. I also installed their control panel at the helm so I can monitor and control the system. I also went with a 24 volt system to give me more storage and have 12 6 volt golf cart batteries which are separate from my house batteries. I can run the boat for about 24 hours with out starting the gen set.
When installed correctly and wired right they work great.
 
psneeld said:
Sounds like many panels I have seen...I guess without seeing it.

The main panel bus has been split...which make part of it a sub panel (in other words)that's connected up when the transer switch is on.
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That is how my inverter is wired. The main panel neutral bus bar is split. The inverter neutrals tie back through the inverter to the safety ground. The bottom right 4 breakers are the inverter breakers. There is an automatic transfer switch that lets shore or generator power flow through.
 
It's only split on the Ship side. On Shore power everything feeds direct from the Main AC breakers.

It's a cleaver and very simple solution. Only confusion was when you buy a boat wired like this from an estate and don't get a chance to ask the previous owner to walk you through it. :)
 
SomeSailor said:
It's only split on the Ship side. On Shore power everything feeds direct from the Main AC breakers.

It's a cleaver and very simple solution. Only confusion was when you buy a boat wired like this from an estate and don't get a chance to ask the previous owner to walk you through it. :)
Click to expand...

I'd have to see a diagram for this one....I guess I'm not seeing where there is lockout to prevent multiple sources of power then.

Of course a picture is a thousand words and my attention span isn't what it used to be....:D
 
swampu said:
Maybe I should have added more environmental details in my question.
1. Boat will be used primarily in the summer on the coast of South Mississippi, it gets very hot here. So the a/c will most likely run a good portion of the time.
2. Boat will be used about 60% of the time as a "mother ship" to support little boat fishing Trout, Snapper, triple tail or whatever we are going to catch and will be running a #400 ice machine to keep food, beer and said fish cold.
3. I have two 12.5kw gensets, although they haven't proven themselves reliable they do run and make water and power. Only time will tell if they are reliable.
4. The inverter, in my case, would only run games, tv, coffee maker or any other devices while the genset is off.

My question would be do you really need an inverter system at the expense of delaying the use of the boat that would function by just using generated power.
Your right about selling the boat to save money.....
Click to expand...

Most larger boats just accept the fact that inverters would be extremely localized exceptions and just run a genset 24x7 when away from the dock. Nothing wrong with it other than the cost of generating unit overhaul on a more frequent basis...then again...most rec craft underutilize their gensets badly enough it kills them in the long. (not usually cruisers...just part timers).
 
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FlyWright said:
Do you mean in parallel to give you 4KW? Or are they 12V output and wired in series to give you 2KW at 24V?
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It worries me to see someone say they installed an electrical component but not be clear about how they actually installed it.

"are they 12V output and wired in series to give you 2KW at 24V?"

I've never tried that and have no reason to, but I suspect that wouldn't work unless there was a way to keep them in phase with each other.
 
psneeld said:
I'd have to see a diagram for this one....I guess I'm not seeing where there is lockout to prevent multiple sources of power then.

Of course a picture is a thousand words and my attention span isn't what it used to be....:D
Click to expand...

Hope this makes sense (if not I'll blame it on the 15 minutes I insisted I'd spend no more on drawing) :)

AC%20System%20Diagram.jpg
 
SomeSailor said:
Hope this makes sense (if not I'll blame it on the 15 minutes I insisted I'd spend no more on drawing) :)
Click to expand...

nice setup...short and sweet....:thumb:

as I said a pic is worth a thousand words...especially after happy hour..:D
 
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