Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

The one time I went tractor pulling this summer that guy that burns up EU3000's had his breaker trip at least twice that I saw. He was parked right next to me. Then they holler at one of the crew and tell them to turn something off in the trailer, reset the breaker and away they go again. He needs a bigger generator but that's what these guys do. If it puts out 3,000 watts they'll keep turning stuff on until it won't hold, then back off one notch and that's where it runs for 7-8 hours every single weekend. And this last summer it was 95-100 degrees every day and I'm sure that didn't do it any good either.

Those EU3000's are too small for what these guys are using them for in their stock car trailers and tractor pulling trailers. But that's what everybody buys because they're relatively quiet in the pits.
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Chris

PorkChopsMmm

Re: Generators, Gen sheds, Gen fuel systems, etc.

This was the first thread I saw where someone had a generator, used with auto-start, with an auto-choke mechanism. Very cool OP. Didn't know those existed. I am getting ready to hook up an auto generator start to my Outback VFX3648 inverter. I was passively wondering how to handle the choke since sometimes I have to fiddle with it on my electric start large construction generator. Looks like I will be manually adjusting come winter time. Bummer! But, now I know what to look for when I buy my next generator. My current generator is an Ingersoll Rand with a Honda GX390 engine. Looks like this. It is a big sucker but is left over from building my house. I plan to buy something more fuel efficient next year.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

PorkChopsMmm wrote: »

I was passively wondering how to handle the choke since sometimes I have to fiddle with it on my electric start large construction generator. Looks like I will be manually adjusting come winter time.

It seems to me that if someone got a little inventive, one of those old thermostatic choke caps like used to be used on carburated car engines could be used, in addition to the vacuum choke pull-off. Some of those choke caps used to have a small electric heater in them that caused the spring to expand and open the choke.

For pete's sake, I don't even know if those parts are available anymore - haven't seen one in ages.
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Chris

PorkChopsMmm

Re: Generators, Gen sheds, Gen fuel systems, etc.

That sounds like an interesting idea. I am hoping just to get it to start most of the time automatically. If I have to adjust the choke once a month I am fine with that. Hopefully that isn't a naive statement.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Most gasoline engines I've seen require the choke to be fully shut for starting cold and then open it gradually as they warm up. Auto-starting a generator with a manual choke can be a challenging thing. You can also used a timed or measured fuel enrichment setup in lieu of a choke for cold starting. But that usually runs into more complexity.

The auto-choke on the Honda is the best, but few gasoline generators have it. Our little Champion 3 kW backup generator also has an auto-choke because it has wireless remote start/stop. The Champion generator also has a rudimentary ECU on it with a stepper motor that controls the choke.
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Chris

techntrek

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

...
At the above numbers for fuel consumption at 5.5 kW rated load for both units, the difference in fuel consumption over a year's time would be 24 gallons of gasoline @ 400 hours. Which is $85 in additional fuel cost over a year's time at today's prices without the road tax. With the road tax it would be a difference of $94 in our state.

The difference is 6.5%, which is probably within the standard deviation of each model, over a sampling of real units in the field. 20% of conventional units off the shelf might be 3.25% worse than the unit(s) tested for the official numbers, and 20% inverter-gensets off the shelf might be 3.25% better than the official numbers, which would make them dead even. Bottom line there just isn't a real advantage between conventional genset and inverter-genset.

techntrek

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

Those EU3000's are too small for what these guys are using them for in their stock car trailers and tractor pulling trailers. But that's what everybody buys because they're relatively quiet in the pits.

Ironically if they moved up to the 6500 not only would it last, but it would be quieter at the 3000 watt load.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

That's assuming those fuel consumption numbers are even accurate. I did a measured fuel consumption test on my new EM4000SX and it burned 57 ounces of 91 octane gasoline with no ethanol in it in one hour @ 3.8 kVA continuous output, driving water heater elements.

If you look on Honda's website it shows rated load for that generator at 3500 watts, max 4000 watts, iAVR 5000 watts. On the data tag on my generator it shows rated load 3800 watts, max 4000, iAVR 5000. On Honda's website it only shows a generic run time, which doesn't really mean much. But for rated load it says it will run for 10.1 hours. It also says the fuel tank holds 6.2 gallons.

The tank was bone empty when I got it and the most gas I could get in it, filled up at the pump at the gas station when it was in the back of my truck, was 6.06 gallons, not 6.2. And according to my fuel consumption test it will run for 13.6 hours at 3.8 kVA output on that 6 gallons of gas. And that's assuming it could get every drop of fuel out of the tank, which it can't. There's a standpipe in the tank that draws the fuel at about 1/2" off the bottom of the tank, so I estimate that there will be about 1 quart left in it when it quits due to being out of fuel.

Actual field test data is the only thing you can rely on. Taking figures off a manufacturer's website, from their sales propaganda, is a little "iffy".

Also, reading the operator's manual for my new generator, not a single mention, chart or anything, relating to fuel consumption in it.
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Chris

Vic

Re: Generators, Gen sheds, Gen fuel systems, etc.

Well, based upon my personal experience, the Honda EU-6500isa is a very solid genset. Have used one for at least 5 years -- got one when they first came out. It is used exclusively for intermediate level battery charging ... solid.

The Honda EU series gensets have a Surge rating of 20-30 minutes, depending upon the model. Change the oil often, let it warm up a bit, and let it cool down under light or no load for a few minutes, and you should be good. In my experience, Honda gensets are very conservatively rated. Would agree that some loads like small compressors, which are hard to start could stress inverter gensets, if they were exposed to this frequently.
Knock, knock, have had very good luck with all 5 of my Honda EU gensets -- two of which are EU 3000is models. YMMV, Vic

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

I've seen a couple weird things with inverter gens. My buddie's EU3000 won't run his electric impact wrench. Plug it in, squeeze the trigger and nothing happens. Plug it into my old Onan in my trailer and it runs the wrench fine - doesn't even act like there's a load on the generator. But the EU3000 runs his 2 hp air compressor alright.
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Chris

Cariboocoot

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

I've seen a couple weird things with inverter gens. My buddie's EU3000 won't run his electric impact wrench. Plug it in, squeeze the trigger and nothing happens. Plug it into my old Onan in my trailer and it runs the wrench fine - doesn't even act like there's a load on the generator. But the EU3000 runs his 2 hp air compressor alright.
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Chris

Now I've got to try that!
I was surprised to find the 2000 could start my air compressor too. It complains, but it does it.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Another thing that refuses to operate on the inverter gen is a Bostich electric nail gun. Same thing as the impact wrench - nothing happens. The gen doesn't overload or error - it just simply refuses to recognize that it's there.

Both of those tools just have a two prong plug on them with no ground pin. I don't know if the Honda detects some sort of ground fault situation and refuses to supply power to them, or what. I have an electric drill with a two-prong plug that will trip out the GFCI on my 2 kW (battery) inverter in my service truck every time. That same drill runs off my generator with no problems and I've taken it apart and ohm'd it to find if there's something wrong with it, but can't find anything wrong in it.
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Chris

BB.

Re: Generators, Gen sheds, Gen fuel systems, etc.

Wonder if the GFI outlet is going bad (lots of electrical noise with brushed motors). I assume there are not Arc Fault breakers involved here (which can trip with universal/brushed motors).

-Bill

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Vic wrote: »

In my experience, Honda gensets are very conservatively rated

Vic, I am very happy with our new conventional generator as well. It puts out beautifully stable power compared to the Generac. Last January my wife bought a new 240 volt electric range with induction cooktop on it. The range is very efficient and the induction elements on the top of it draw about 1.6 kW, except for the big one which is 2.5 kW. The inverters run the induction cooktop with no problems without the generator helping out, unless she is using three or four of the induction elements at once with other loads on.

The convection oven in it, however, draws considerable power if she is using the broiler. But otherwise it is about 4.8 kW until it gets up to temperature, and then it cycles on and off.

With other loads on in the house and shop the oven will invariably cause the generator to start for load amps. Her new range is an Electrolux from Sweden and the controls in it are all electronic. It had some issues on generator power before and would sometimes display an error code on its LCD display if a surge load (like the well pump) came on and the frequency dropped momentarily because the generator couldn't react fast enough.

The inverters sync with the generator during a load start situation. So they do whatever the generator does unless it drops well out of spec, and then they spit it off and let it recover.

Our new Honda is only 2/3's the size of our old generator (for max continuous rated output) and her range works perfectly with the new generator. The inverters have to carry more of the load than they did with the old one because I have the amp limit set in the inverters at 3.8 kVA for the new one. But when her range is going on generator power I can abuse it by even using my Lincoln 225 amp spark welder in the shop and that new Honda still maintains perfect voltage and freq so her range does not complain about it. Last night I was welding on a wind turbine tower for a bit with the shop door open. I can hear the exhaust note of the EM4000SX change when it goes into "iAVR mode" when I strike an arc with the welder but the lights don't dim or flicker - it is just plain impressive

It's amazing that Honda sticks more technology in a portable genset than a major manufacturer puts into a stationary unit.
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Chris

inetdog

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

Another thing that refuses to operate on the inverter gen is a Bostich electric nail gun. Same thing as the impact wrench - nothing happens. The gen doesn't overload or error - it just simply refuses to recognize that it's there.
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Chris

Are you talking about the generator not going out of "search" mode when the gun or wrench are connected? Or the gun and wrench just doing nothing even though the generator is putting out full voltage? For the former, do they work if you first connect a load like a light bulb to cause the generator to deliver full voltage?
My guess is that the two devices do not put their motor or drive coil online unless there is a steady voltage to their control elements first.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

There was lights going in the trailer, plugged in to the twist lock plug that supplies the trailer power. Their generator was only 10 feet from me and I was just sitting there in my lawnchair alongside my trailer watching all this because watching this crew work is like a comic relief act some days.

The little green output light was on on it. The red overload light never came on though, nor did the push button for the outlet pop out. They were going to nail up their canopy with some 2 x 4's for braces and it didn't work. So there was the usual *&^%$#@! - one of the guys plugged that electric impact in to try it and that didn't work either. More *&^%$#@!.

Plug the air compressor into that same outlet and it runs fine. It has to be something in the tools. The only thing I could think of is that Honda generators have a floating neutral and the ground pin in the plugs is connected to the generator frame so there's no neutral-ground bond. Because the plugs on those tools are two-prong maybe the inverter sensed some sort of ground fault issue and refused to power up the outlets. The air compressor they plugged into it (that worked) had a three prong plug.
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Chris

inetdog

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

There was lights going in the trailer, plugged in to the twist lock plug that supplies the trailer power. Their generator was only 10 feet from me and I was just sitting there in my lawnchair alongside my trailer watching all this because watching this crew work is like a comic relief act some days.

The little green output light was on on it. The red overload light never came on though, nor did the push button for the outlet pop out. They were going to nail up their canopy with some 2 x 4's for braces and it didn't work. So there was the usual *&^%$#@! - one of the guys plugged that electric impact in to try it and that didn't work either. More *&^%$#@!.

Plug the air compressor into that same outlet and it runs fine. It has to be something in the tools. The only thing I could think of is that Honda generators have a floating neutral and the ground pin in the plugs is connected to the generator frame so there's no neutral-ground bond. Because the plugs on those tools are two-prong maybe the inverter sensed some sort of ground fault issue and refused to power up the outlets. The air compressor they plugged into it (that worked) had a three prong plug.
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Chris

Unless there is a GFCI outlet on the generator, there is nothing that would prevent it from trying to supply power to the tools. But if a GFCI tripped, it would require manual reset. And if the tools caused the generator itself to trip, the rest of the load like the lights would have stopped too.

The only thing I can think of that comes even close to explaining it would be a totally wacky extension cord that swapped the neutral and ground wires, combined with some other wiring errors like a ground to neutral bond where it should not be. The true test would be to plug the tools' built-in cords directly into a three-wire outlet on the generator (after making sure that the breaker for that outlet was reset.) If that is what they did, then I give up!

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

LOL! You know - when the plugged the air compressor in they did not use that cord. It's totally possibly, knowing those guys, that one of em "rigged" the cord at some point. LOL! I never thought of that. If they exchanged the neutral and ground in a plug it would still work fine connected to a non-GFI outlet on a grid system! But on the Honda it would be open circuit.

My other thought was that some inverters have built-in GFCI protection and they either shut down the plug or the entire inverter if there is a ground fault. Knowing Honda, it would not surprise me if the inverters in their inverter gens have built-in GFCI protection.
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Chris

inetdog

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

LOL! I never thought of that. If they exchanged the neutral and ground in a plug it would still work fine connected to a non-GFI outlet on a grid system! But on the Honda it would be open circuit.
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Chris

When all else fails, try logic. :-) (easier said than done).
If there were a GFCI function in the generator itself rather than the outlet, I would have expected the lights to go out when they pulled the trigger.

westbranch

Re: Generators, Gen sheds, Gen fuel systems, etc.

I have frequently run 2 prong plugged tools on my Eu3000i, a craftsman 7" skill saw and a Makita 1/2 inch drive impact wrench with narry a blip... they just ran as normal

alyaz

Re: Generators, Gen sheds, Gen fuel systems, etc.

This is golden... thanks :-)

oil pan 4 wrote: »

I work on diesel generators from 6 to 600kw.
My larger one happens to be a perkins.

The best way to prevent wet stacking is to change the oil and keep a some what clean air filter on it. The generators I find that are wet stacked typically have been ran for many months maybe even years with no servicing, have an air filter with a 1/4 inch of caked on dirt and being left to run at no load for many hours and most of them consume a lot of oil.

alyaz

Re: Generators, Gen sheds, Gen fuel systems, etc.

yes, our experience shows that the inverter generators (Honda), while quiet and somewhat fuel efficient in comparison to others is admirable, are a PITA when it comes to true off-grid operation. Start up loads seem to kill the inverters/brains and are just not worth the grief. our perkins diesel has been operating flawlessly (touch wood) and i have steered at least a dozen if not a hundred people away -with favourable results - from the Honda EU generators... sad but true...

ChrisOlson wrote: »

We looked at those units. The inverter generator does not have the surge power that the conventional has. Our generator is used primarily for load management because we have 240 volt appliances (range, clothes dryer, water heater and well pump), plus 240 volt machine tools in my shop. Our generator rarely runs for battery charging. But it will run about 400 hours per year for load management - and it should be running at full rated load so it reduces the load on the inverters and batteries properly for the hour or so that the heavy load is on, and runs at the best efficiency.

At the above numbers for fuel consumption at 5.5 kW rated load for both units, the difference in fuel consumption over a year's time would be 24 gallons of gasoline @ 400 hours. Which is $85 in additional fuel cost over a year's time at today's prices without the road tax. With the road tax it would be a difference of $94 in our state.

Another consideration for inverter style is that I have seen several EU3000's with burned out inverters. The ones I have seen are used primarily in stock car trailers and tractor pulling rigs, and they are used at full load continuously for several hours running lights and AC units in the trailer, air compressors, and engine block heaters to heat up diesels in pulling tractors for competition. One tractor pulling guy I know burned out three of them in June and July and the dealer refused to cover the last burnout under warranty because he is supposedly "abusing" the generator by running it at continuous rated load for hours on end.

What scares me about inverter generators is that if one fails out of warranty it will cost just about as much to fix it as a new generator costs. I can fix a conventional unit myself. And even fixing a conventional generator made by Honda is not going to be cheap because Honda is really proud of the parts they sell for their equipment.
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Chris

Cariboocoot

Re: Generators, Gen sheds, Gen fuel systems, etc.

alyaz wrote: »

yes, our experience shows that the inverter generators (Honda), while quiet and somewhat fuel efficient in comparison to others is admirable, are a PITA when it comes to true off-grid operation. Start up loads seem to kill the inverters/brains and are just not worth the grief. our perkins diesel has been operating flawlessly (touch wood) and i have steered at least a dozen if not a hundred people away -with favourable results - from the Honda EU generators... sad but true...

Never seen any such poor performance from an inverter/generator. If it's sized right and used right it works right. Evidently people have been trying to run very large loads from very small generators. This is called "being stupid".

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Cariboocoot wrote: »

Never seen any such poor performance from an inverter/generator. If it's sized right and used right it works right. Evidently people have been trying to run very large loads from very small generators. This is called "being stupid".

Inverter generators used at >50% load are inherently less efficient than conventional wound field type anyway. So buying one to run it at rated capacity all the time is not the right application for it. And guess what sort of loads a properly designed off-grid system puts on the genset?
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Chris

Cariboocoot

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

Inverter generators used at >50% load are inherently less efficient than conventional wound field type anyway. So buying one to run it at rated capacity all the time is not the right application for it. And guess what sort of loads a properly designed off-grid system puts on the genset?
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Chris

Almost none.

My system charges from panels 90% of the time. Mr. Dave Sparks will regale you with tales of the many generator-less systems he's installed. That won't work everywhere of course!

But you sure wouldn't use a gen designed for "occasional use" as prime power. Nor would you buy a 10 kW diesel-powered set to supply a few hundred Watt hours now and then.

There is nothing wrong with either type of generator. It's stupid when people don't evaluate their needs properly and then go pick the wrong type of gen.

The worst is buying one of those cheap knock-off units that won't last any time at all. A good generator of the right type is the only way to go.

My Honda EU1000i has over 6000 hours on it. The EU2000i is catching up slowly at just about 5000 hours now. Yes, I use them for more than just backing up the solar.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Cariboocoot wrote: »

Almost none.

Well, yes. And there are many off-grid systems that can do without a genset. But the normal off-grid installation, especially anywhere above the 45th parallel, is going to have a genset as an integral part of the system. If it don't, the people live pretty frugal in the dead of winter.

So what I'm saying is that when you design an off-grid system designing it with an over-sized generator, or designing to run the generator at anything less than 75% load is poor design. Even the inverter type generators are horribly inefficient at light loads (measure or calculate your kWh/gallon of fuel). I will beat it with a conventional every time.

The inverter generator is going thru two extra steps that involve electrical losses that conventional generators don't have. And internal combustion engines also have inherent limitations in efficiency, and gasoline engines are most efficient at wide open throttle and peak torque. The old saying is, "you can't squeeze blood out of a turnip".
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Chris

Cariboocoot

Re: Generators, Gen sheds, Gen fuel systems, etc.

Yes, the efficiency of an inverter-gen goes down as the load is reduced. The same is true for a conventional generator. But it is better on an I-G at light loads because it can reduce engine speed and thus fuel consumption. Standard generators have more 'overhead' in just running at their fixed RPM when connected to nothing. Having used both types on the same system I know this to be a fact.

If the doctors ever let me pick up my tools again I've got a Honda 3500 that needs rebuilding; I'd like to see how that performs against its I-G cousin on my system. I expect it will be pretty horrible for supplying a small amount of power. Mainly I got it because the EU2000i was less than perfect for running power tools off-grid; had a hard time starting the compressor when cold.

And if I don't get at it someone is going to be inheriting a lot of equipment they don't know how to use!

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

Cariboocoot wrote: »

Yes, the efficiency of an inverter-gen goes down as the load is reduced. The same is true for a conventional generator. But it is better on an I-G at light loads because it can reduce engine speed and thus fuel consumption

Yes, inverter generators are best suited to applications that use the generator at less than 50% load most of the time, and where super "clean" power is needed. Because of its ability to save fuel at lighter loads compared to a conventional of the same rated capacity, the inverter style takes less careful sizing of the genset to the system and loads.

However, a properly designed system that uses a conventional at >75% load at all times will get better overall efficiency and more kWh/gallon of fuel. Therefore, it is my belief that full-time off-grid systems should shy away from inverter style and spend more time with proper design and generator power management (using Generator Support, peak load support, and careful application of prime power) using a conventional instead.

If you are charging batteries with a generator (of any type) and inverter charger, discussions of efficiency are pointless. The batteries and generator fuel will be the major cost items for anybody that lives off-grid full time. I don't think enough emphasis is placed on proper generator sizing and design in off-grid systems. And I doubt most professional installers even understand it. I see way too many systems that have a 8+ kW generator for loads that rarely exceed even the capability of the inverter, with the generator being sized to charge batteries at max amps and carry loads at the same time, instead of using sound engineering principles in designing the system.
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Chris

mtdoc

Re: Generators, Gen sheds, Gen fuel systems, etc.

ChrisOlson wrote: »

Yes, inverter generators are best suited to applications that use the generator at less than 50% load most of the time, and where super "clean" power is needed.

Exactly right.

But here's the thing:

A modern, large, full creature comfort, energy efficient home that uses propane (and possibly wood) for heating and cooking can run at a baseline of 100-300 watts with only occasionally having short lived larger loads when running a washer, microwave or for fridge start up, etc. So with such a low baseline load (and totaly daily power need < 10kWh) an inverter generator makes perfect sense.

It may not be a good choice for an off grid home in a climate that requires summer air conditioning or a home using electric heating elements but that does not mean it is not the best choice for a properly designed energy efficient home in some climates.

ChrisOlson

Re: Generators, Gen sheds, Gen fuel systems, etc.

mtdoc wrote: »

So with such a low baseline load (and totaly daily power need < 10kWh)

I don't know where things went haywire along the way. But we have trouble getting our off-grid home down to that level of daily consumption anymore.
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Chris