Stacking Inverter Generators

Small Engines Charcoal Gasification
#21

If it were me I would try and find two inverter that are already 220 volt with sync ability. Simplify the system as much as you can but also add as much redundancy as you can. Dont get attached to brand names, they all come from basically the same place.

If you dont have an off grid inverter system yet and that is part of your plan. Then generators are irelivant. The inverters will handle the loads and the split phase. If you run a small generator or a larger generator; its not going to matter. kW/hours are kW/hours. you are going to put the same energy into your battery bank regardless of generator size. A small generator is just going to take longer to get there verses a larger one will get there faster. Energy input is still going to be relitivaly the same.

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#22

I have a question for you brainiacs. If the inverter on the generator fails will the generator still produce usable power like a non-inverter generator? Other than it will run at lower RPM to match the power draw is there any reason that the inverter gen is quieter and how does the enclosed generator dissipate heat and if it can be run totally enclosed why would any open frame generator not be able to be fully enclosed cutting decibels as well.
Side note.
If your generators are at risk for being stolen you may try and enclose them with an electric fence charger.

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#23

No. But then again Define usable. :slight_smile: chances are it is generating in 3-phase similar to a car alternator. Then it is converted to dc and smoothed/filtered so it is a constant dc current, then fed into the inverter portion. So if the inverter fails, the usable current, would most likely be a high voltage dc current, but you would also have to dig through a ton of wiring to figure out where that is coming out to bypass the inverter. Not exactly something I would recommend, but technically possible in maybe a SHTF scenario.

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#24

When I tore the 9500 down there are two legs that were labeled 120 volt with three wires each. Those leads connected from the generator head to the inverter box and then there are two 120 volt legs out. I think its just dirty AC going in but I could be wrong.

So it probably is 120 volt AC as I didnt see a diode or bridge rectifier. But some how I would think you would need a voltage regulalator and a means to combine the three wires?

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#25

Pretty much what I thought Sean. I’ll stick with what I have. I know some homesteaders, mechanically inept, who couldn’t use their truck for two months because it stalled out or over revved. Two garages insisted it was the trans. Turned out to be a bad throttle position sensor which they had already replaced earlier so didn’t think it could be the problem. I guess the garages were looking for a bigger buck job. Finally found one place that diagnosed it right. I’m pretty sure no sensors are manufactured in the US nor any other electronics we daily use.

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#26

They use the intake fan that is typical on the front of the small engines but have ducting that goes thru the air cooling fins on the engine block to ducting with a puller fan built into the generator head.

50% of the noise comes from the intake of the carburetor and the engine its self. They put better mufflers on these as well. The enclosures have sound deadning insulation foam and that is what actually quiets them down. But its not a lot. I tore all that stuff off and its not that much louder if even noticable. lol

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#27

It seems funny and it is certainly a lot of money… The irony is it is kind of relative, a 48-50kw whole house stand alone generator is in the 20k range which would have to run all the time you were off-grid because it has no storage. It has about a zero percent realistic chance to pay for itself in just electric utility savings. You are mainly doing it in case of emergency.

With solar and/or maybe even wood/char gas, there is a much greater then zero chance you can get the system to pay for itself eventually even if the whole system has a higher upfront cost. so 12k for inverters 10k for 30kw of storage (30kw is the avg daily household use in the US.) then throw in a generation source. A full pallet of bi-facial panels is 7.5k for 13kw, so basically 2.5 hours of sun to fill up the battery bank. all from signature solar. (you can go cheaper on the panels i was just plucking prices) (and there is still wiring and mounting, etc costs).

Then throw in some tax credits, and it might be the same price as a whole house generator except the main wear part, is the engine, and you can use a 500 dollar 5kw generator for 6 (12 on wood gas) hours a day to fill up the battery bank, and throw it out when it breaks.

I am certainly not saying it is going to be feasible because of initial upfront cost because understandably a number of people can’t just spend that much.

It also isn’t necessarily fiscally impractical. It gets weirder and weirder to look at every year when you start looking at the numbers, when you are accustomed to thinking a generator is the cheapest solution.

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#28

Yup and you dont need to build it that big. You dont make the off grid system fit the home. You make the home fit the off grid system. You can do a lot more with less especially today. The system I bought for $5000 bucks can easily support a two bedroom home. But that is going to gas appliances, LED lighting, more eficient electric appliances. Spend the money on more effecient appliances instead of investing into a system to support existing ineficient appliances.

Also there is no reason you cant build a system in chunks and ease into it. No need to spend huge upfront cost. Just get a system that is stackable. One small inverter to start with and a single battery. Run a generator to support larger loads at first. Then add on the second inverter run with that for a while. Then add another battery and then add another one later. I dont see where you would need more than a 6 kW inverter. You do have to learn to do things differently, you are not going to be running all apliances at one time. You learn to run one thing at a time its just an adjustment is all.

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#29

LOL I started thinking about it, and I was just going to post a ‘one more thing’, but subtly different…

Also certainly look at how to best take advantage of tax credits. It very well could be piecing together a stackable system works in your best interest. I forgot exactly how they implemented them and a lot of times for middle income it can be advantageous to claim it 3 years in a row in smaller chunks. However, sometimes you only get to claim a credit once like for energy efficient appliances and windows and such was like that. I don’t know if it still is.

You -can- do it that way, but you have to be careful and it is a pain in a household with more then one person, and they have two separate residences, so it gets trickier. And they are probably used to being on grid.

Along the same lines, just replace one circuit at a time, and budget the money for the next upgrades. but the cost savings isn’t nearly as much.

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#30

I don’t know. i will try to pull it up later when I have more time. :slight_smile:

was that 3 wires soldered together or in a 3 prong connector? If it was a connector it is most likely 3 phase, and there is a rectifier on the inverter board which most likely is a small box. then a cap after it for smoothing, and they might skip the cap since 3 phase is relatively smooth to begin with. The rectifier itself isn’t very big.

Chances of it being dirty are high, because it doesn’t matter. Even frequency doesn’t matter.

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#31

Three terminals each side. The aluminum housing is filled with epoxy with all the electronics on the back side. So no fixing that if it goes bad

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#32

It is very easy to search out and find the wiring diagram for a Honda EU7000is 240VAC unit.
Theirs have two separate WYE connected three phase generating coils sections then inputting separately into the unitized inverter box. No doubt by mechanical positioning on the charging coils getting the split phase.

I do have a factory service manual I bought for the Honda EU2000. 120 VAC only.
The test points are for an engine running 150 to as high as 300+ VAC at the output coils.
The AC frequency here is high, and wild varying with RPM. But is smooth sine-wave.
In the Honda’s Inverter box there is visibly three transformers and three very large capacitors.
The 2000’s manual go on to many other inputs points checking, for outputs checks. Any failing then a component is specified changed out.

Search up for actual realistic failures on the main brands inverters and you just do not find them.
Lots and lots of put up obvious failures on the loose tye wrapped components in the cheapest brand inverter generators. On these you will never get more than what you pay for. Just like the cheap inverter welders.
On the Harbor Freight units lots of complaints about the 12vdc not working. Or non-working USB charging ports. These are a whole separate output coil with its own rectifier. Not a big deal. Use a real separate plug-in regulated 12vdc battery charger. Much better for the battery. Use your own wall-wart USB chargers.
What is inside the big aluminum finned inverter box? I Don’t precisely know. I Don’t care. Use. Abuse to find the good brand applications. Then truck-on with your life.

TomH we’ve been reliant on someones electronics in vehicles for ignitions and charging regulation since the 1970’s.
Use the owners experiences now readily accessible via internet to sort for the OEM durable versus the not-durable. I’ll pay more for OEM replacements on the gives long life durable. Needing them on durable systems selected; so infrequently. Often the new OEM replacement part has been upgraded, changed. No way to know quality on aftermarket electronics replacement parts. Many failures. Early low hours failures.

Ha! Now you still want to know about generators sound abatements??
Only one smarty-pants S.U. write-up at a time. Gives me brain-aches.
Steve unruh

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#33

Generally true, but the details can get you. Our inverter-charger can charge the main batteries at just above the recommended minimum rate, but only with split-phase 240 at the input. Single phase (120v) halves the charging rate. So for “recommended” best battery life, split-phase 240, with 3kw+ is the way to go. Less will certainly work, but I don’t know what the cost is, in terms of battery life.

This is one of the little frustrations in scaling up power and complexity. I have some experience with older inverters and batteries, for van camping. It’s fun to have programmable inverters and pure lead-carbon batteries, but there are still things that are hard, or maybe impossible, but very difficult to even know are problems until you wade though the owner’s manuals and programming manuals. It’s fun if you can make it work, but a pain if you can’t.

I should note that I have a life filled with blessings, and my frustrations are not to be compared to the real, serious problems much of the world faces. Careful analysis shows that I really have nothing to complain about. Alas, I still do :slightly_frowning_face:

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#34

It is 3-phase then. They fill it with epoxy to prevent water or to keep from getting sued if someone tries to fix it.

Right, It doesn’t matter if you are rectifying it, then inverting it. :slight_smile:

What controls the engine speed? is that baked into the rectifier/inverter case too?

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#35

O.K. TomH.
How to quiet open framed four-cycle single cylinder electrical generators. Save me a few hundred words letting someone else do the talking. Watch; and CC read along this. Most of the info is in his words. Pay attention up thru 5:00 minutes for the why’s.
Then at 5:00 minutes on; get to the lowest-tech, anybody can, no-welding, how-to.
And bonus points for the additive detail he gives right at 7:35 that I’ve learned to add also:

Now go back re-load up as view as Watch on YouTube; and open up the little “. . . more” tab and read his ~120 words summery answering comments. All very true.

Now how’s this relate to the fully enclosed modern engine driven Inverter-gnerator units?
Taller, thicker head overhead valve air-cooled engines are combustion events quieter that the old valve-in-block flathead types. Period. This is easily observable true. Sell off, crap fuels trials use-up your flat-heads and get along with the 1990’s and on engines. Only invest into those with iron cylinder bores.
The sixtyfiveford fellow refers to this flathead disadvantage twice if you truly watched, and read him for content and details.
Another inverter-generator make less noise . . . mostly lower engine RPM operating. This generates less noise. Period.
Why truly most modern EFI vehicles take a page from the good 'ol best of oversized I-6 and V-8 American engines and are now geared to be ran then majority of the time at 1800-2600 cruising along RPM. Using larger four cylinder engines for the most part to do this. Less noise. Less wear and tear.

The totally enclosed IC engine driven Inverter-generators do use a combination soft non-sound conduction thermal plastic panels; enclosures; and in the case of the suitcase ones, as the whole supporting clamshell structure.
This supporting structure is less-sounds-transmitting. And to not be re-transmitting sounds outwards is why the manufacture supplier to Harbor Freight and other large marketed units use cast aluminum upright posts. You can see this in MattR’s 9500 stripped down pictures. Tube steel framing would be cheaper. More noise re-emitting. Then requiring more specific points engineering noise measures added.

Go back to sixtyfivefords video and along in the 7-8 minutes and he said sound damping OSB panel were quieter than plywood panels. OSB matching the sound reduction of drywall panels.
I use, and have used; both A-frame style layed, plywood panels and OSB. The 6+ months rain soaked wet plywood decreases sound then just as good as OSB. And do not edges deteriorate when like left out in the weather OSB can do.

YMMV. But, I will use every cheat that I can and give you a consolation pat on the back from the other side of Life’s finish lines. Give you your E for effort. I’ll always go the W for winner. The A for achiever.
Steve unruh

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#36

very true. That is why I wasn’t making recommendations. Just a general idea. :slight_smile:

Generally speaking the slower you charge a battery the longer life it will have.

The devil is in the details though like Life batteries I pointed out while they should last for like 20 years, don’t work in below freezing which may mean you have set up a system in each house or keep the shed warm. There is no sense in using lead acid batteries even in this case because they cost too much per charge cycle.

They may also now require 200a service instead of 60a or 100a service. Which means to be up to code, you may have to have a 400a service at the shed and 200a at each of the subpanels in the houses and it will require running new wires. I believe panel upgrades and associated wiring is covered with the tax credits now as well. But it is certainly an additional expense because wire isn’t cheap. It is all part of the preparation for running out of =cheaply= extractable oil which is most likely in the next 30-40 years and prices will start to spike before that. It is easier and cheaper to not wait until the last minute, but certainly some people will.

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#37

Made me think of my copper tube framed pyramid I made in the early 70’s to meditate under and become cosmically conscious. That didn’t work for shit, but it did have slanted sides. Maybe my generator under one could figure out how to regenerate it’s fuel. I’m not crazy. My mother had me tested. :face_with_spiral_eyes:

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#38

Thats what is really going on, the goverments are not going to spell that out as this will crash the global markets. I have sources that have conveyed this to me from all over the world. That time frame is not 30-40 years we are talking in the next decade. Thats why they are not tapping our oil, they want to run the others out first. That will make our oil worth more, as the prices rise. This will be a problem long before those resources are tapped. We have already hit peak oil; we are now on the down slope and this will soon be a topic, that no one can dispute. It will simply be reality.

The car companies did not willfully transition to EV’s they were forced.

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#39

There is a oil field that is called the Liberty Bell in Alaska and it was found many years a ago. We have never tapped into it and it is a big oil field. Out of sight out of mind and don’t talk about it. Yes it is on federal land. We have only tapped into the smaller fields up there close to it. Easy to get at nope not with all the environmental impack issues we have to deal with in the USA. We will just keep buying oil a put in the governments caverns for future reserves. Did you know you can put oil into old oil fields too. If you can pump it out you can put it back into the ground.

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#40

To keep it shorter… There is a TON Of misinformation being thrown around by both sides. It can vary regionally. Like Europe could be out in 10 years. Or we could have 50% of the current production in 10 years. It doesn’t mean we don’t have oil, but the price of what is left goes through the roof. To add to that China and India are increasing consumption.

The main issue is we don’t know how long it will take, and it is the -price- that affects the economy. so we find have cost effective solutions otherwise it drives up prices. The longer we work at it, the better solutions we have.

The issue with the automakers is they got burned hard with the EV1/Ford Ranger by really poorly written California policy with their zero emissions mandate. It is a posterchild law of what not to do.

The to top it off, oil -investors- did a hostile takeovers in part to get rid of the electric vehicles.

Under the Obama rules, we didn’t mandate EVs. They have emissions credits that they can trade from other companies to meet the emissions/mileage requirements. It is a subtle change in philosophy, we care about the US fleet mileage, not the individual manufacturers. Biden is trying to push it a lot harder then I think is possible.

Then we helped Tesla, to demonstrate there is a market for EVs. It is a much different discussion in the boardroom if Tesla is selling 100k EVs a year, then if there is no proven market and you say you want to build EVs.

We are hoping by 2030 for price parity of the equivalent EV. But that was a rushed timeline and I have only seen a few things on the technological side for fast charging, and there isn’t even a charging network that can support it. It needs to be about 1mw charging.

Liberty Bell is the mining district in Alaska where they mainly mine for gold. There is another project called Liberty that is off-shore near prudhoe bay. Prudhoe bay has a lot of oil. You may be right, or it may be mixed up information. It also could be a bitumen deposit similar to the tar sands. I don’t know. But there isn’t enough to feed the world’s thirst for oil and only a small fraction of the US needs. Bakkan is a large deposit and output is 1m/barrels a day which is a small fraction of US needs. So will there be oil? yes, will you be able to afford it? probably not. The timeline for when that will occur, no one really has a great idea, but the more work we do to come up with cost effective solutions the easier it gets to transition. The longer we stretch it out, the more time we have.

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