Inverter install question

Many installations remove the steel bars and use jumper wires so that the breakers which are to be powered only by shore power and those powered by the inverter can be selected by routing the jumper wires. I can't recommend that a non-electrician do this, but it is relatively easy.

A do suggest that a boat owner know how this works as the boat owner should always be double checking the work of a hired worker.

Marty

Inverter brands

For a brand ranking, I was one of the last hold outs on Xantrex, as I has mostly good luck with the last Freedom series inverters and I loved the Link 2000 controller. When they came out with the newest SW series, I started seeing infant failures and recalls. I finally moved away from them.
I've used Victron, and think they make a great unit, but their tech support sucks. This reason alone keeps me from recommending them.
Outback seems to make a good unit, but I'm not a fan of their controllers.
The brand I recommend, (and have on my own boat) is Magnum. Great units, nice controllers, and great tech support. You can actually talk to someone that knows what they are talking about, and speaks clear English! They also have the BMK (Battery Monitor Kit) that adds complete battery management info to the controller. The only issue I'm aware of with these units is that the 2000 watt series doesn't seem to play well with some of the all in one washer / dryers like Splendede. However, the 2800 watt, which I have, works just fine with them. (I also have the washer / dryer). Still don't like the controller as much as the old Link 2000, bit it's as close as it gets.
Full disclosure, I work for a service company that are dealers for all of the above and more.

Brent Hodges said:

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.

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Brent, my inverter chassis ground is connected directly to the engine block and not the ground bus bar. Is this incorrect or just another way of connecting to the boat's grounding system?

Marty

Tom.B said:

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.

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Bay Pelican said:

Many installations remove the steel bars and use jumper wires so that the breakers which are to be powered only by shore power and those powered by the inverter can be selected by routing the jumper wires. I can't recommend that a non-electrician do this, but it is relatively easy.

A do suggest that a boat owner know how this works as the boat owner should always be double checking the work of a hired worker.

Marty

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As Marty indicated above, the buss bars can be removed, cut, and re-installed.

Jumper wires can be installed to connect the buss bars around the breakers that will then be used for the inverter.

As with anything on a boat, hiring a professional isn't necessary, but taking the time to learn to do the job correctly and safely is.

ksanders said:

As Marty indicated above, the buss bars can be removed, cut, and re-installed.

Jumper wires can be installed to connect the buss bars around the breakers that will then be used for the inverter.

As with anything on a boat, hiring a professional isn't necessary, but taking the time to learn to do the job correctly and safely is.

Click to expand...

I cut my bus bar into two pieces. Then ganged the inverter powered circuits in the bottom right hand corner of the main panel. The breaker to feed the inverter ac power is on the main panel set of breakers. The inverter powered breakers are essentially on a sub panel. They are powered with shore power through an automatic transfer switch when connected to shore or generator.

ksanders said:

As Marty indicated above, the buss bars can be removed, cut, and re-installed.

Jumper wires can be installed to connect the buss bars around the breakers that will then be used for the inverter.

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Mine was done (by a professional electrician - I know because I found the receipt) exactly as Marty and Kevin indicated. The bar was cut, the three bottom circuits have their own, smaller bar. These are jumpered through the switch that selects between inverter and shore power. This is the switch I've already ordered the proper replacement for, shown on the first page of this thread. I suspect the undersize switch that's there now was installed by a subsequent owner. I don't think an electrician would do that.

So it sounds like you removed the bar(s) that buss all the breakers together and have, for a lack of a better way to describe it, a remote buss for the breakers? Y'all got any pics of this type of install? I am not at all uncomfortable doing it myself, but it would require a great deal of dis-assembly and time. My breaker panel is in a pretty awkward place.

BruceK said:

I`d like to have an inverter, just to run a TV at night, without running the genset

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Google car inverter review 2013
These may be the thing

Tom.B said:

So it sounds like you removed the bar(s) that buss all the breakers together and have, for a lack of a better way to describe it, a remote buss for the breakers? Y'all got any pics of this type of install? I am not at all uncomfortable doing it myself, but it would require a great deal of dis-assembly and time. My breaker panel is in a pretty awkward place.

Click to expand...

I dont have photos, but here it goes.

Most AC panels are made up of columns.
Each column is made up of breakers.

The breakers are connected together on the power feed side using tin plated copper bars, with holes drilled in them for attachment to the breakers.

The best method is to separate the AC panel into two panels. One being fed from shore power, and one being fed from the inverter. This is done by removing the copper bar, and cutting it into two sections.

This is the best method because it logically separates the inverter loads from the shore power loads. This is the method I've used several times. The challenge with this method, is that you have to re-arrange the load wires to put all the inverter loads in one physical section. This can make for a messy looking panel, and possibly require splicing wires, something I almost never do. As an electrical professional I seriously dislike butt splices. Installing a terminal strip is a much better solution.

Another method, which I've also used is to pick the breakers that you want to have on inverter power, and remove the buss bar from that breaker only. You then jumper around the removed section using a 10AWG wire (on a 30 amp panel). Then you wire the breakers that you freed up to the inverter output through a buss bar. Then you mark the breakers that are on inverter power. A colored tye wrap through a hole in the handle works great

I've done it both ways, and prefer the first method, although the second method works just fine as well.

Tom.B said:

So it sounds like you removed the bar(s) that buss all the breakers together and have, for a lack of a better way to describe it, a remote buss for the breakers? Y'all got any pics of this type of install? I am not at all uncomfortable doing it myself, but it would require a great deal of dis-assembly and time. My breaker panel is in a pretty awkward place.

Click to expand...

I'll try. As you look at the picture, the lower left and right and the upper 2 on the right are non inverted; shore power or generator only. All the others are inverted. You can see where I cut the buss bars and added the jumper from the third breaker on the right to the third breaker on the left. You can also see the jumper on the bottom two. I hope you can make some sense out of this.

Nigel Calder's book gives several examples as a reference.

Hello again
Have not been able to log on for Few days.
Anyway my install issue is this i have read the inst book prior to my orginal post the reason i am asking for assistance is i dont want to put in another ac panel as the book suggests. I am all for putting in a breaker from the shore power inlet to the inverter. But still dont see a good way to get the power to the main ac panel from the inverter while still being able to use the selector switch in order to prevent backfeeds thru the shore power cord. I dont want the inveter on when the shorepower is on. I would like the abilty to have ac from the inveter while using the generator ( such as starting the coffee on the inverter then switching to generator when the time comes with out a power surge) i just dont want the power to leave the boat thru the shore power cord.

The way the boat is at this time is
Shore power to 30amp breaker to shore/gen switch to main ac panel

What i want to run the inverter for is the microwave, outlets, refer (if needed if the dc side fails) (maybe electric heater while underway only if the diesel heater fails).

Many folks are of the mind that we should not wire the orginal ac panel to the inverter. Why? Might we foget to turn something off? That tells me that when some are switching from shorepower or generator loads they are not turing off individual loads at the CBs. Dont folks turn off individual loads prior to switching power sources?? Ie when disconecting shore power or turning off the generator. I turn on 1 circuit at a time and do the reverse when shutting down.

Not trying to be a smarta$$ but this is what i read in all the manuals for generators is this this wrong?? Isnt this also why we have the remote panels is to be a backup for us to look at to see of the power draw is what it is supposed to be for what is currently running?

Am i just not seeing this correctly? For those of you that say hire someone i had already planned to but wanted to run wires, CBs etc prior to i cant afford to have someone at $95 per hour to run wires. But i will gladly pay for connection and inspection.

HN,

I installed an inverter (with all the proper cabling) in a salon cabinet directly above the batteries. The inverter DC feed is only 6 feet from the batteries. A single 15A extension cord is run to the aft counter with a power strip. I use this power strip for the microwave, coffee maker and second refrigerator. Occasionally, we use it to power a ceramic heater on its low setting (600W) while underway.

When on shore power, the power strip is plugged into the counter outlet powered by shore power. When underway or at anchor, the power strip is plugged into the inverter extension cord. No other outlets or systems are powered by the inverter.

I am considering adding a switch to control the AC source to the counter's outlet, thereby saving me the need to change plugs. I'd just throw the switch to change from shore to inverter.

Harbor Nights said:

Hello again
the reason i am asking for assistance is i dont want to put in another ac panel as the book suggests. I am all for putting in a breaker from the shore power inlet to the inverter. But still dont see a good way to get the power to the main ac panel from the inverter while still being able to use the selector switch in order to prevent backfeeds thru the shore power cord. I dont want the inveter on when the shorepower is on. I would like the abilty to have ac from the inveter while using the generator ( such as starting the coffee on the inverter then switching to generator when the time comes with out a power surge) i just dont want the power to leave the boat thru the shore power cord.

The way the boat is at this time is
Shore power to 30amp breaker to shore/gen switch to main ac panel

What i want to run the inverter for is the microwave, outlets, refer (if needed if the dc side fails) (maybe electric heater while underway only if the diesel heater fails).

Many folks are of the mind that we should not wire the orginal ac panel to the inverter. Why? Might we foget to turn something off? That tells me that when some are switching from shorepower or generator loads they are not turing off individual loads at the CBs. Dont folks turn off individual loads prior to switching power sources?? Ie when disconecting shore power or turning off the generator. I turn on 1 circuit at a time and do the reverse when shutting down.

Not trying to be a smarta$$ but this is what i read in all the manuals for generators is this this wrong?? Isnt this also why we have the remote panels is to be a backup for us to look at to see of the power draw is what it is supposed to be for what is currently running?

Am i just not seeing this correctly? For those of you that say hire someone i had already planned to but wanted to run wires, CBs etc prior to i cant afford to have someone at $95 per hour to run wires. But i will gladly pay for connection and inspection.

Click to expand...

Several posters have provided some sage advice and guidance. Take another look at this post from Moonstruck and this post from Brent Hodges. They seem to answer your question, unless I'm missing the question.

Marty, yes it does accomplish the same thing the way yours is done, but it shouldn't use the engine block as a conductor in the circuit. If it connects to the same place as the negative battery cable you're ok. Another way to say it is that it's ok (not ideal) to use a bolt on the engine block as a power post, but not ok to use the engine block as a conductor in the circuit.

And as far as Tom B "being damned" if he's going to hire a professional to do his work..... It is perfectly acceptable for a person who REALLY UNDERSTANDS WHAT HE'S DOING to do his own inverter wiring and install. The reason I made the comment I did was that the original poster didn't seem to really understand the wiring, and some of the suggestions he was getting at first were way off base. A little bit of electrical knowledge and a little misdirection can be a very dangerous thing.

Brent Hodges said:

Marty, yes it does accomplish the same thing the way yours is done, but it shouldn't use the engine block as a conductor in the circuit. If it connects to the same place as the negative battery cable you're ok. Another way to say it is that it's ok (not ideal) to use a bolt on the engine block as a power post, but not ok to use the engine block as a conductor in the circuit.

And as far as Tom B "being damned" if he's going to hire a professional to do his work..... It is perfectly acceptable for a person who REALLY UNDERSTANDS WHAT HE'S DOING to do his own inverter wiring and install. The reason I made the comment I did was that the original poster didn't seem to really understand the wiring, and some of the suggestions he was getting at first were way off base. A little bit of electrical knowledge and a little misdirection can be a very dangerous thing.

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Brent, your insight and comments are very much aprechiated. As an electrical professional, I attempt to take my land based experience, and apply it to boats.

If I ever make a comment that you feel is in error, please feel free to comment, either in the thread, or if you prefer via PM. I'm a person that believes that we learn from our errors, and will take any constructive critisizim with a smile and an open mind.

Brent Hodges said:

And as far as Tom B "being damned"

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Perhaps you misunderstood... More than half the fun of this whole experience is doing things and learning to do things myself. Yes, I will make some mistakes and will likely do a few dangerous things along the way (and perhaps take and give some bad advice), but that's a risk I am willing to take to be the best boater I can be. Paying someone THAT much money not only extinguishes that fun... it puts a beat-down on my bank account in the process.

Am i just not seeing this correctly? For those of you that say hire someone i had already planned to but wanted to run wires, CBs etc prior to i cant afford to have someone at $95 per hour to run wires. But i will gladly pay for connection and inspection. (endsnip)

I have customers run their own wiring all the time, and that's fine with me. Pulling cable through a boat is my least favorite part of the job. I'll suggest this: Gather your inverter, controller, whatever you have and call the professional for a planning meeting. Pay him an hour or so to layout your system and tell you where to pull what wires, where to mount what breakers, etc. Then you can do all the ground work that you're able to. He can come back, make all the connections, and test the system.

Harbor Nights said:

For those of you that say hire someone i had already planned to but wanted to run wires, CBs etc prior to i cant afford to have someone at $95 per hour to run wires. But i will gladly pay for connection and inspection.

Click to expand...

Answer:
Try this: Pay the professional to come over to the boat, make a plan with you, direct you as to where to pull what type of wires, cb's etc. Then you can do all the ground work you want to. He can come back when you get that part done and make the connections. I work with customers like this all the time.
This way you'll get a good, safe install for the least out of pocket.

>This way you'll get a good, safe install for the least out of pocket.<

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However do expect to pay for travel time .

Brent Hodges said:

Another way to say it is that it's ok (not ideal) to use a bolt on the engine block as a power post, but not ok to use the engine block as a conductor in the circuit.

Click to expand...

Most small engines are quite happy to conduct charging and starting currents through the block, along with instrumentation current. Look at your engine wiring diagram and you will probably see that it is indeed a conductor of at least two very high current circuits and a multiple of smaller ones.

This is not mean to condone using the engine as a large busbar, if you need to add ground points, install a busbar and connect it to the negative battery terminal. The engine should not look like an electrical porcupine.

This is meant to say that those who want to do their own electrical work should understand that there are several means to safely accomplish a goal and being constrained by absolute statements can lead to more problems than intended. Try to understand the why of the way things are done.

Rick B makes a point about engines using the block as a conductor, and he's right. Engine circuits are a whole 'nother animal in the electrical system. The do use the block as a conductor, (although most high output alternator manuf recommend running a real ground cable to the negative buss which tells you they don't trust the conductivity of the block and it's connections) and they are not required to have overcurrent protection in their cables. The issue being discussed here is a SAFETY ground cable. I stand by my "absolute" statement that the engine block should not be a conductor in a safety circuit.

Brent Hodges said:

... most high output alternator manuf recommend running a real ground cable to the negative buss which tells you they don't trust the conductivity of the block and it's connections...

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There isn't much debate about the conductivity of an engine block. The issue with a dedicated alternator ground return is based on the eventuality of a high resistance in the alternator attachment - caused for example by the supports becoming loose - and the return current taking a path which most likely begins at the propeller shaft and returns to the alternator through the gearbox, and crankshaft. That will destroy every bearing and bearing surface along the way. It is an all too common event when welders are too lazy to provide a ground as close as possible to the arc, particularly on steel or aluminum vessels.

Larger engines with electric starters tend to use one with a dedicated ground terminal that isolates the starter current from the engine entirely in order to avoid the kind of problems I described above.

There isn't much of an issue with safety grounding of low voltage DC circuits. The chassis grounds are safety grounds for ac line currents. Those grounds are supposed to be connected electrically with the DC grounding system but, in my opinion, are best handled by a ground bus that is independent of (but electrically common) with the battery negative and engine case. There is no reason other than the perception of simplicity to use the engine as a busbar.

I thought I would jump in here with a possible alternative?

My system is somewhat similar to FlyWright's in that it is completely independent, and there has been no modification of the factory AC and DC distribution panels. I have the usual genny & shorepower system, the genny is 20kw and can power all AC appliances on the boat simultaneously, including chargers. Shorepower is 50 amp 120/220. Battery charging of house & engine banks is by two dedicated 30 amp chargers. Inverter is an older Heart 4000 watt?, the charging function is not used and no AC is connected to it. The inverter system appears to be factory installed? as all switching / controls fit logically and neatly within the AC/Dc distribution panel. The control panel for the inverter is mounted in there as well

All that said, the way it is set up is that "in addition to the normal AC outlets throughout the boat", I have hardwired AC outlets strategically placed throughout the boat (labeled inverter) that are powered by the inverter only and have no connection whatever to the genny or shorepower AC. These plugs are mostly side by side the normal AC outlets, apparently so a lamp or appliance can be simply unplugged from one and moved to the other if desired. Some things like the TV entertainment center and some lamps are left permanently plugged into the Inverter outlets but mostly they are empty.

The actual wiring appears remarkably simple but I'm going by memory and I haven't quite figured it all out yet. There is ridiculously heavy DC cables from the house bank to a rotary battery switch, from the switch the DC goes to the inverter, the inverter AC output feeds the string of AC outlets around the boat. That's it! The floor mounted Gunnert deep freeze in the galley (only used underway on trips) is somehow directly connected into the system as well and were it not for this, we would rarely use the inverter.

At first glance I thought the system to be a bit Mickey Mouse but the wife, who is easily annoyed by any form of inconvenience, has "yet" to complain about having to occasionally move the plug on her appliances in the galley from one outlet to the other. (If she's happy, I'm happy).

In my mind, after reading this thread, it seems a small sacrifice compared to the complex total integration of the electrical systems. Simple can sometimes be good.

I forget who made the suggestion of pulling the wires and letting a pro do most of the rest, I think it was the OP. In retrospect we could have done that and prob saved a chunk of change. One of our larger expenses was replacing our old house bank (which turned out not to be connected to anything, the house was powered by the starting batteries ) with 8 six volt golf cart batteries. I do agree that if you go this route you should meet with the pro first and lay out a plan. The electrician put the inverter in a different place than we were thinking, which worked out much better and used less cabling (saved us money) so if we had purchased and pulled wires to the location we were thinking, we would have been wasting money on wiring (cables! really) while saving on labor.

Re having the separtate outlets, I guess that really depends on what you want an inverter for. We really wanted to be able to run our ice maker. To my husband, having an ice maker is one of the rewards of going from sail to power. We really appreciate the seamless transfer of power when we turn off shore power or the generator. Having to get on hands and knees to switch outlets every time we switched power sources would get old pretty quick. But I could see it for a lamp or a toaster or something small with an accessible outlet, it would be easily managable.