Inverter install question

Good day
I am going to install an inverter and want to have the inverter power all my outlets in my ac panel. (Yes i am aware of the concern of high draw items). My question is how to you wire in the power to the inverter with the use of a "shore power - generator" switch? My inveter will have the ability to turn on the inverter power if ac is lost if i program it that way. I dont want it to back feed the shore power cord.

The unit i am going to install will be the Xantrax 2012. ( i am aware some of you dont like this brand but that is not my question. I am looking for the best thoughts on how to wire this item in and still use my main ac panel that has a c.b. for battery charger

Thanks

OK

AC power to the inverter from a spare breaker in your AC panel, large enough for the inverters rating.

DC to the inverter from the batteries through a fuse and a on/off switch

Remove the strap, buss bar, or whatever means your panel uses to supply power to the breaker(s) you want the inverter to power.

( BEST WAY)AC power from the inverter to a buss bar mounted behind your panel, then individual wires to the breakers you want to power.

(ACCEPTABLE WAY) AC power from the inverter to one of the breakers you want to power, then daisy chain the breakers together.

Mark each of the breakers you use in some way. A small colored tye wrap in the breaker handle works for me.

If you want to protect against a inverter failure, take the output of the inverter and run it to a a/b switch, with the load side being the common, the breaker that feeds the inverter being one leg, and the output of the inverter being the other.

another way to think about

You can upgrade to a 3 way rotary switch (expensive)

AC Rotary Switch Panel 30 Ampere 3 positions + OFF, 2 Pole - Blue Sea Systems

or add a 2 CB slide lock sub panel that would accept your shore power and inverter...then that would feed where your shore power is now on your shore/gen rotary.

Traditional Metal Panel - 120V AC 30A Toggle Source Selector - Blue Sea Systems

What does the wiring diagram in the book say?

Larry M said:

What does the wiring diagram in the book say?

Click to expand...

And why leave your inverter on when you are off the boat for an extended period?

our inverter/charger is wired as indicated in my post above.

It is left on 24X7X365 and powers all of the outlets in the boat, the ac only ice maker, the networking /satcom cabinet, among other things.

You can design your electrical system so that it needs your intervention, turning on, and off things, or you can design it so that everything works automatically.

I prefer the latter.

BTW, You can even set it up so that the generator starts automatically when the battery gets to a certain percent of charge, then turn back off. I have the gear to do that, I just haven't had the time to get it installed. Next summer.

There are three ways your shore power / inverter arrangement can be set up.

Shore Power Everything

Shore power can go to a selector switch so that when you select shore power it goes directly to all your AC appliances. In this case to use the inverter you select the inverter and it turns off the shore power.

Shore Power Only to Big Draws

Shore Power Shore power can be split at the distribution panel to power just the AC, water heater and the inverter. In this case the inverter handles the small loads and the shore power handles the heavy loads. When not connected to shore power the inverter does not power the heavy loads.

Shore Power Only to Inverter

Shore power goes only to the inverter/charger which passes through shore power to the AC appliances on board. This works only to the extent of the maximum pass through permitted by the inverter. This limitation of the inverter could be 20 amps or 30 amps whereas the boat may have a greater shore power inlet.

Your desire to have all AC circuits run through the inverter raises a question as to whether you have air-conditioning and / or an electric hot water heater. The issue here is that you have a 2,000 watt inverter and it may be pressed to handle these items. If the inverter is not capable of powering these items you would be unable to use them even if connected to shore power. Thus the preferred method would be to exclude this big draw items from the inverter so that when shore power is available you could use the big draw items on the shore power directly and the rest of the appliances are powered by the inverter pass through of the shore power.


Marty

My inverter can put out 2000 Watts. W=A*V, so 2000=16.7A*120V. In other words, the most 120VAC my inverter can put out is around 16 Amps.

The AC circuit breakers are each 15A, so it basically can power one circuit.

But we all know you're not drawing the full 15A all the time on any one circuit.

So the PO wired three breakers (port outlets, stbd outlets, and fridge) to a 20A, DPDT switch. One way feeds from the inverter, the other feeds from the same (shorepower) AC bus the rest of the breakers feed from.

Leave the switch in "AC" and the inverter is out of the loop. Flip it to "Inverter" and the inverter powers those three circuits. It passes along shorepower if it's available, and switches to inverter power when it's not. I basically leave it on "Inverter" all the time.

Obviously, I'd trip the breaker on the inverter if I ever plugged in more than it could handle. Likewise, I'd fry the 20A switch if I drew anywhere near the maximum the three breakers could handle. Then again, the whole panel is fed by a 30A shorepower cord, so those three circuits would have to demand 2/3 of my total capacity before there was a problem.

I run the microwave, fridge, vacuum cleaner, lights, etc and never have a problem, shore power or not. I do plan to update the switch and wires to it so they're a little more robust, just to be safe. I also plan to add a few outlets on their own circuits so I can plug in things like space heaters if needed, without going through those three inverter circuits.

Good advice here. One reminder ..... 8 out of 10 inverters I see do not have a grounding conductor on the chassis ground lug. Considering most inverters I see were installed by "pro's" I find this surprising .... or maybe not

Bay Pelican said:

There are three ways your shore power / inverter arrangement can be set up.

Your desire to have all AC circuits run through the inverter raises a question as to whether you have air-conditioning and / or an electric hot water heater. The issue here is that you have a 2,000 watt inverter and it may be pressed to handle these items. If the inverter is not capable of powering these items you would be unable to use them even if connected to shore power. Thus the preferred method would be to exclude this big draw items from the inverter so that when shore power is available you could use the big draw items on the shore power directly and the rest of the appliances are powered by the inverter pass through of the shore power.


Marty

Click to expand...

If my memory serves correctly, most of the inverter installation manuals I've read indicate that this is how to install the inverter. IE break the shore power to AC panel line and insert the inverter/charger in series.

The theory is that the transfer switch portion of the inverter is rated for 30 amps, the same as a shore power connection.

The problem with this installation methodology is that while it works, it ignors the realities of large loads and how they affect battery life.

It also ignores the reality that most inverters are not rated for the full 30 amps of shore power, while in invert mode.

This "power it all" method does work though, and it is the easiest method to get the inverter installed, although it requires effort and knowledge at load managment, even more so than just running off of shore power.

A better method is the one I think you described, and I described above where the inverter is only powering the loads the owner actually wants to power. This method involves more work during installation to split the AC panel into "inverter loads" and "non inverter loads", but virtually eliminates the owners need to manage loads if done correctly.

I'm thinking of replacing my wimpy DPDT toggle switch with one of these:


Obviously instead of "Generator" it will say "Inverter". The load will be just those three circuits I want to feed from the inverter. The "shorepower" input will be from the same bus as the rest of the circuit breakers.

CaptTom said:

I'm thinking of replacing my wimpy DPDT toggle switch with one of these:

Obviously instead of "Generator" it will say "Inverter". The load will be just those three circuits I want to feed from the inverter. The "shorepower" input will be from the same bus as the rest of the circuit breakers.

Click to expand...

That will work great.

...or is space is an issue, this BlueSea 6337 (or similar)...

boatpoker said:

Good advice here. One reminder ..... 8 out of 10 inverters I see do not have a grounding conductor on the chassis ground lug. Considering most inverters I see were installed by "pro's" I find this surprising .... or maybe not

Click to expand...

After reading this I checked my inverter and, surprise, no ground wire. I assume I should run this wire to the electrical panel where the other green wires go. Correct?

Ron

Check before you connect this lug to the panel. Perhaps it should be connected directly to the engine block.

windmist said:

After reading this I checked my inverter and, surprise, no ground wire. I assume I should run this wire to the electrical panel where the other green wires go. Correct?

Ron

Click to expand...

Check your manual carefully. Sometimes the inverter ground goes to the DC ground. My inverter grounds with a 2 gauge wire that way. All inverters probably don't work the same way. If you wire it up wrong you can back feed it and ruin the inverter. My inverter powered circuits do not have the neutral connect to the common bus. The neutral goes back to the inverter and the ground from the inverter to the DC ground. Sounds weird, but it works.

I say again, read your manual carefully. Don't fry yourself or the inverter.

>I assume I should run this wire to the electrical panel where the other green wires go. Correct?<

Click to expand...

No too dangerous from a corrosion danger.And then there is electrocution ,,,,

The neutrals and ground must be switched so the active SOURCE is the only point of grounding.

Read Da Book is a great idea.

FF said:

The neutrals and ground must be switched so the active SOURCE is the only point of grounding.

Click to expand...

FF

Could you expand / explain this. Clearly I am not an electrician but I have never heard of switching the chassis ground.

Marty

At the power Source the neutral and ground are joined.

Coming into your home , or into the boat yard is the Source .

A noisemaker is done the same way as is an inverter, it is a Source.

The problem comes when something like an inverter is installed , but not switched .

The dock neutral and dock ground will be joined in your vessel at the inverter ..

Then any current found on the neutral will be installed in the water.

Measure the voltage difference between the ground and neutral at your power pole, to see why the zincs depart.

On a 240V supply the neutral ,when only providing 120V, (most 120V power poles) will be very loaded , a reverse polarity could cause electrocution.

Just a FYI on neutral to ground bonding...

Most inverter/chargers will bond the neutral to ground in inverter mode, and open the neutral to ground bond when running in charger mode.

So, when shore power is present the inverter/charger is in charge mode, ther ground bond is not there.

When shore power is removed the inverter/charger goes into inverter mode and bonds the neutral and ground.

This is a standard feature of inverter/chargers.

I'm loathe to jump in here as I don't know much about inverters. but I did want to share how ours is set up in case it helps to consider another alternative. A friend gave us a Xantrex inverter. Not wanting a free inverter to cost us an arm and a leg, we went through several months of researching how to install it and ultimately chose to spend an arm and a leg to have it professionally installed. After much discussion with the installer, we chose to have the inverter wired to only two of the six switches on our AC panel, the port and starboard outlets. It does NOT power the hot water heater, the battery charger (there is a separate charger for the starting batteries, the house batteries are charged by the inverter) the refrigerator (gets DC power if no shore power) or the range. If we need any of those other things while away from shore power, we have a generator.

The invertor has a control panel where we can turn off and on the charging and inverting functions and select "power share" to tell the unit how much of the incoming power it can use for charging. That is handy to limit how much power the xantrex is using so the generator does not overload and trip if we are also using other power sucking items.

So if we are leaving the slip and about to turn off shore power, we make sure the inverter is "on". this does not mean it is inverting, just that it is ready to invert if shore power is removed. Then when we do turn off the shore power, the inverter automatically takes over. If we have shore power on and we do not want the inverter to take over if the power goes out for some reason, we just make sure the inverter is "off". The inverter powers the two switches for outlets regardless of what the selector switch is set to (generator, off, shore power). now say the switch is on generator and the inverter is "on". If the generator is on and providing power, the inverter does NOT provide power, the charger will come on and charge as long as power is coming in. Instantaneously when we turn off the generator, the inverter takes back over and powers those two switches. If we left any other switches on when we powered down, they would lose power. they are not connected to the inverter.

I hope that makes some modicum of sense. I cannot explain how the wiring was done since we did not do it.

I have to tell you though, they did make one mistake and it was a pretty big one. We went out for a multi day trip shortly after we had this done and were having power issues on the 12 volt side. we were running the generator to charge the house batteries but after a couple of days our lights were dimming--the battery monitor looked like we should be ok and the batteries seemed to be charging up fine when we ran the generator. When we went to leave we could barely start the motors, we had to turn on the generator and turn on the separate charger for the starting batteries for a bit. The pros had wired the house panel to the starting batteries and only the inverter was wired to the house batteries!! oopsies.

There is a LOT of misinformation going on in this thread. A lot of armchair electricians giving advice they don't actually understand. To the original poster, if you don't REALLY understand how an inverter / charger works, and should be integrated into your ac power system, I strongly suggest you hire a marine electrician that does. I'm not trying to be a smartass, just trying to protect you and your boat.
By the way, I am an ABYC certified marine electrician, and have installed dozens of inverters of many brands. I do know what I'm talking about.

Pineapple Girl gave a very good explanation of how a good inverter system works, and should be used. I always recommend turning the inverter off when you leave the boat so in case of power failure, the inverter doesn't run batteries down and cause you to lose bilge pump function.
A few quick points as I don't have a lot of time right now.
The GROUNDING conductor (the green shore power wires going to and from the inverter) should NEVER be switched. The neutral to ground connection is broken inside the inverter when on shore power.
I would never wire an inverter between the shore power inlet and dist panel. First, you have to have it on it's own breaker for safety. Second, you may think you will always remember to manage the heavy loads, like water heater, stove, air cond, etc but you won't. It needs to be wired like others have suggested, fed by it's own breaker and it's output connected only to the loads you intend to use it with.
As for that chassis ground: The inverter will have a spot for a large chassis ground connection. ABYC says that the chassis ground needs to go to the main dc negative buss, and needs to be no more than one size smaller than the positive battery cable feeding the inverter. I ALWAYS install that cable. It's purpose is to protect the ac grounding conductor in case of an internal short in the inverter between the ac and dc circuits.

Brent Hodges said:

By the way, I am an ABYC certified marine electrician, and have installed dozens of inverters of many brands.

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Silly install issues aside, what is your ranking of charger/inverter brands.

With some expertise online, can I ask something. I`d like to have an inverter, just to run a TV at night, without running the genset, nothing else. LED TV says it draws 65 watts. I can buy a stand alone pure sine wave inverter putting out up to 300 or 600watts, they use alligator clips going to the battery. Is that an ok way to go, or must I wire it in properly. I have a charger I`m ok with. Thoughts?

BruceK said:

With some expertise online, can I ask something. I`d like to have an inverter, just to run a TV at night, without running the genset, nothing else. LED TV says it draws 65 watts. I can buy a stand alone pure sine wave inverter putting out up to 300 or 600watts, they use alligator clips going to the battery. Is that an ok way to go, or must I wire it in properly. I have a charger I`m ok with. Thoughts?

Click to expand...

Why not just buy a 12V TV? This is what we have on Siesta, in fact all of the loads on board are run from the 12V house battery.

We also have a 300W inverter, only for use when we are away from the marina and essentially this is only used to charge devices such as iPads, laptops and my electric razor.... Inverters are frankly too inefficient, but they do have their uses.

Mike

I should have added that I try to only run the inverter when we are underway, so that I don't use valuable battery power.

Mike

p.s. This weekend I am replacing the house battery bank and also installing a Victron battery monitor. The main reason is that our load profile has just changed due to installing an Eberspacher diesel heater a couple of weeks ago that uses 12V DC to run its' fan. The heater is great but not too good on the current house battery.

The heater is great but not too good on the current house battery.

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The old ones started with a glow plug and huge resistors , talk about BIG AMPS!!!

In reality the new heater is not too bad as it draws less than 3A when running at the maximum level. Also at that level it is only using around 0.28 liters per hour of diesel. These two combined and I am now getting around 2.2kW of heat.

My real issue is the batteries which have a 10 year life are 10 years old, so time to change!

Mike

I would like to have my inverter be more integrated with my house AC system, but looking at my panel, I don't see a way to separate the loads easily without a complete dismantling of the breakers (there are steel "bars" between the two AC 30A legs that span the entire bank of breakers) and I will be damned, with all due respect Brent, if I want to pay a marine electrician $100+/hr. to redo the whole bit. Besides, learning how to do it myself is 99% of the fun and I am okay with the risk ;-) Anyway, it takes very little effort and time to thrown out an extension cord/power strip to plug in only what I need to run on the inverter at any one time. It sure keeps me from ever overloading it or killing the batteries.