Choosing a good generator

waynefromnscanada

Re: Choosing a good generator

inetdog wrote: »

Have you tried any *new* Briggs engines? Times can change.

I guess like everything else, it wouldn't surprise me if Briggs went downhill, but way back in 1982, I built my house using a "homelite" 1200 watt generator powered by a Briggs engine, and believe it or not, that generator still runs like new today, 30 years later, and it didn't really have an easy life at times. To this day, it's never needed repair. Guess it can safely be said that they don't make things like they used to. lol Of course I looked after it and kept the oil changed.

icarus

Re: Choosing a good generator

Don't get me wrong,, Briggs engines run,, it is just that they are inferior to Hondas. The carbs in particular are pains. I have se era, running Briggs engines from washing machines, water pumps etc that are now relegated to under the bench status, as they have been replaced with more reliable, quieter Hondas.

Tony

waynefromnscanada

Re: Choosing a good generator

Agree re the carbs. I got lucky with my old generator, it has some sort of drain back carb. Takes a few more cord pulls to start, but on the other hand no gas remains in the carb between run times, thus no gunk in the carb. Only one I've seen that way. It's mounted right on top of the fuel tank. Or I should say the fuel tank is mounted to the bottom of the carb.

Rybren

Re: Choosing a good generator

Have any of you had any experience with the Hyundai Inverter Generators? The online reviews have been pretty good and they're 1/2 the price of a Honda/Yammy. I know that you generally get what you pay for, but...

Coach Dad

Re: Choosing a good generator

I'm not understanding the logic of a 1000W or 2000W inverter for an off grid backup.

1) If your system is sized correctly you won't use it too often.
2) If you havn't had sun in a couple of days, you want to do your bulk charge and stop when you get to Absorb.
3) While you are doing your bulk charge you want to run your other high loads (well pump, vacume cleaner, washing machine etc)

Once you have your batteries up to Absorb again and your high loads done, you turn off the gen and go back to batteries.
So using the above logic, I would want a large generator not a small inverter.

2manytoyz

Re: Choosing a good generator

My generator is sized for the charger I use with my battery bank. I have a 900 AH battery bank, and a 75A Iota charger. Ideally, it should be a 90A model, but I've found this one works well, and it doesn't take long before the charge rate drops off.

Here's the actual current usage by my charger with the charger supplying the full rated capacity (I had to put a heavy load on the battery bank to accomplish this):



If I want to run a heavy load while charging, I simply run it from the inverter. While the vacuum does pull a constant heavy load, the washing machine does not. Here's some testing I've done:

http://www.alpharubicon.com/warlord/altenergy/altwashclothes2manytoyz.htm

Things I can't run from my alt-power setup, or the small generator: Pool pump, central air, stove/oven, water heater.

Things I can run directly from the generator, but not all at once: microwave, TVs, computers, lights, both fridges, fans, vacuum, shop power tools, 5000 BTU window A/C unit, or our entire 25' travel trailer with 13,500 BTU A/C unit. Heck, I could even run the dishwasher!

The fridge, stove/oven, water heater, and furnace in the camper, all operate from onboard propane tanks.

I have no need of a larger generator. This one sips fuel. It'll run that A/C unit for over 8 hours on 1.6 gallons of gas.

I've also performed "grid down testing". Throw the breakers for a day or two, see how well the system performs. During that time, I also used my generator & Iota 75A charger to replenish the energy used overnight by the inverter to run my critical loads:



Bigger generator = more noise (hey, HE has power!) & a lot more fuel consumption if not an inverter type.

swmspam

Re: Choosing a good generator

Apparently there are too many options with pros and cons for each one.

There's some awesome gensets just for 48V battery charging, the premier consumer-available one being the Kohler 6VSG 6kW Variable Speed Direct Current Generator for $5500. This bad boy has a 725cc two-cylinder natural gas engine with pressurized oil system (oil filter!) and is made for continuous full-power operation. Since it is DC, it is not locked into a single RPM and can run variable from 2300-2900. It's perfect, except the price is sky-high. I could spend that kind of money on lots of other things. The Alpha Group (same company that owns OutBack Inverters) also makes a similar product. I haven't called them for availability yet.

The new two-cylinder engines from Honda and Briggs (Vantage) also look great. It's hard to find a commercial generator assembled using the components I want. And if I do find something close (such as the Kohler 6VSG), the price is staggering.

Why? The message is: for battery charging, the engine-to-alternator ratio gets skewed. Big engine (725cc) with small gen head (6kW). Battery charging is tough duty. Consumer generators easily slap 12kW heads or larger onto the same engine displacement (look at the Generac Guardians).

Another interesting example is the Generac Ecogen. The Ecogen uses a 530cc two-cylinder natural gas engine running 2600RPM belt-connected to a 6kW 60Hz AC alternator rated for continuous-duty (including battery charging). Excellent! However, it runs $3700. For this amount, I could get a Generac Guardian 17kW with a 992cc engine 3600RPM direct-drive AC alternator! Why is the pricing so lopsided? What's the advantage of getting the Ecogen when I could get a much bigger engine and alternator for the same money?

stephendv

Re: Choosing a good generator

swmspam wrote: »

Another interesting example is the Generac Ecogen. The Ecogen uses a 530cc two-cylinder natural gas engine running 2600RPM belt-connected to a 6kW 60Hz AC alternator rated for continuous-duty (including battery charging). Excellent! However, it runs $3700. For this amount, I could get a Generac Guardian 17kW with a 992cc engine 3600RPM direct-drive AC alternator! Why is the pricing so lopsided? What's the advantage of getting the Ecogen when I could get a much bigger engine and alternator for the same money?

It could be because one is rated as a prime power gen, the other as an emergency backup(?). See: http://www.dieselserviceandsupply.com/Prime_vs._Standby_Power.aspx One clue is that the Guardian is a 3600rpm engine, very unlikely that it is rated for continuous operation.

Cariboocoot

Re: Choosing a good generator

Coach Dad wrote: »

I'm not understanding the logic of a 1000W or 2000W inverter for an off grid backup.

1) If your system is sized correctly you won't use it too often.
2) If you havn't had sun in a couple of days, you want to do your bulk charge and stop when you get to Absorb.
3) While you are doing your bulk charge you want to run your other high loads (well pump, vacume cleaner, washing machine etc)

Once you have your batteries up to Absorb again and your high loads done, you turn off the gen and go back to batteries.
So using the above logic, I would want a large generator not a small inverter.

1) If your system is sized correctly a 1kW or 2kW generator may well be what you want.
2) If you haven't had sun in a couple of days you start the gen and Bulk up. If you haven't had sun in four days you need to go all the way to finish Absorb. Inverter-gens are at their best for such a situation.
3) Yes, indeed. But some of us don't have enough heavy loads to run where fueling a full-size gen makes sense. The first rule of off-grid is conservation.

Trust me. The Honda EU2000i is absolutely perfect for my use. That does not mean it is perfect for everyone.

Joe J

Re: Choosing a good generator

I use a Generac 8 kw XP gas model. Surge power is up to 12kw. It has been very good. Like you said it comes with an oil filter which to me is very important. Sure a low RPM gen is best but it comes at a high cost. To save money on a really big whole house gen I did this instead. I wired my 4 ton heat pumps with hard start kits and because of this the gen has no problem running them although I run them one at a time. They also have back up strip heaters in the coils so I put a switch on the thermostat to turn them off as the load would be to great. I have had 10 thru 110 degree weather when the power went out ( I live in the south USA ) and have had no problem at all heating or cooling the house. To charge batteries this might be a little overkill but for around $1,500 dollars why not?

swmspam

Re: Choosing a good generator

It could be because one is rated as a prime power gen, the other as an emergency backup(?). See: http://www.dieselserviceandsupply.co...dby_Power.aspx One clue is that the Guardian is a 3600rpm engine, very unlikely that it is rated for continuous operation.

The Generac Guardian is obviously a standby/backup generator. That's why 17kW capacity comes relatively cheap.

The Kohler is not a continuous or prime power generator. It is air-cooled and intended to operate intermittently to keep batteries charged. But when it is running, it can operate steady-state at full rated power until the batteries are charged. One clue is the Kohler has a very fancy brushless three-phase PMG alternator. This doubles or triples (or more) the cost of the alternator. It is also designed for battery charging, which means the system is oversized to cope with the poor power factor of the reactive load presented by the batteries. Battery charging is around 0.6 power factor, so the system is probably overbuilt by a factor of (1/0.6) = 1.7x. So now we know why the Kohler costs more for just 6kW.

So this leaves the Generac Ecogen. It is explicitly advertised for battery charging for renewable energy systems. So we can reasonably assume it has the same "overbuilt" rules as above. But he Ecogen is less overbuilt than the Kohler and uses a standard alternator, which combine to make it cheaper.

So here's the fun question: If I operate the 17kW Guardian at 50% (8.5kW), then won't it behave like an overbuilt 8.5kW system? For the same money, why's a 6kW Ecogen operating at 100% better than a 17kW Guardian operating at 50%?

BB.

Re: Choosing a good generator

swmspam wrote: »

So here's the fun question: If I operate the 17kW Guardian at 50% (8.5kW), then won't it behave like an overbuilt 8.5kW system? For the same money, why's a 6kW Ecogen operating at 100% better than a 17kW Guardian operating at 50%?

One would think so--But if they still will not honor the warranty if installed in an off grid application with documented loads at 50% of output--Wonder what else they are dancing around.

Many gensets seem to shake themselves apart... Heavy loading, lots of hours just means it will hit that point of failure sooner...

Less than 100 hours a year (emergency backup)--It could be a decade before "something happens"... At 2,000+ hours a year (5+ hours a day @ 365 days a year), could happen in 6 months.

If a generator/motor shakes a lot (lots of vibration) during normal operation--I do not trust them (I had a 4 cylinder engine shear bolts holding on the generator and shake other stuff off too on an old truck--Seen a gas to diesel conversion for an Engineering School motor generator test set chew up the coupling between diesel and generator head--lots of impulse from diesel, lots of momentum from generator head. And full of shredded rubber and metal in a few hours of use).

-Bill

2manytoyz

Re: Choosing a good generator

An interesting thing to consider is fuel consumption. In 2004, we had back to back hurricanes that knocked out all power in the area for 18 days. I had a motorhome, and had left FL for GA, so I missed much of the aftermath. Two coworkers stayed. One had a large conventional generator, the other a Honda 2KW.

The conventional generator consumed about 1.5 gallons per hour. The Honda about 1 gallon per 8 hours. Since the power was out, the gas stations were closed since they couldn't pump gas.

The first generator needed 36 gallons per day. The other 3 gallons per day. In the course of 18 days, one needed 648 gallons of gas. The other needed 54 gallons.

648 x $4/gallon = $2592. 54 x $4/gallon = $216. A difference of $2376. These figures are ESTIMATES, but not far off the mark.

So we had a lessons learned discussion at work. Now we ALL own inverter type generators. The owner of the conventional generator initially said "they cost too much". I paid $1147, then received a $100 rebate through Yamaha. That one event, would have paid for my generator twice.

Granted, they both ran their generators constantly the entire time, but during a FL Summer, it's HOT! The Yamaha EF2400iS generator I have, will run a 5000 BTU A/C unit from idle (1/4 load), and use 1.6 gallons per 8+ hours. Before/during/after a hurricane, the weather is usually nasty enough that solar isn't effective. The storms also hit the FL Panhandle and took out a section of I-10, along with the natural gas line feeding the state. Those with NG fueled generators had no fuel.

I keep a few 5 gallon gas cans filled all the time. Each can represents a day's worth of fuel. I have another 10 cans that are empty stored in my shed. When a storm approaches, all the cans are filled. Between solar, and the fuel sipping generator, I can last a long time. Furthermore, I can replenish the battery bank during the day with solar/generator, and run all the critical loads, including the window A/C at night, from the battery bank. Very quiet method.

Food for thought.

Edit to add: The coworker with the conventional generator had to drive out of the county everyday in search of fuel. The other had plenty on hand. He also has a boat that holds ~100 gallons.

ChrisOlson

Re: Choosing a good generator

swmspam wrote: »

So this leaves the Generac Ecogen. It is explicitly advertised for battery charging for renewable energy systems. So we can reasonably assume it has the same "overbuilt" rules as above. But he Ecogen is less overbuilt than the Kohler and uses a standard alternator, which combine to make it cheaper.

We had a EcoGen for roughly 18 months. It is designed to integrate with inverter/charger systems (including two-wire start), but it is far from a prime duty genset at it's 6 kW rating. At 1,100 ft altitude it's maximum output is 5.6 kVA and it will maintain that for roughly one hour at an ambient temp of 59 degrees F and 29.92" Hg (standard conditions), about 20 minutes at an ambient temp of 100 degrees F, and roughly an hour and a half at 30 degree F ambient. Then the voltage starts to drop and it won't maintain 240 volts anymore due the windings starting to heat. To maintain the voltage at 240 and freq at 60 Hz continuous the EcoGen will only produce very slightly over 4.5 kVA @ 59 degrees F.

Engine rpm doesn't make any difference as to whether or not a generator is rated for prime duty or standby. What makes the difference is the genset's ability to maintain it's rated output 24/7/365 on prime duty, while the same genset's standby rating will be higher. Even gensets designed for standby duty can have a prime rating. I worked on (mostly megawatt-class) gensets for Cummins for 19 years and almost all of them are medium speed diesels, regardless of whether or not they are prime duty or standby gensets. Just that the prime duty units are considerably de-rated from the same unit in a standby configuration.

I'm not familiar with the Kohler DC unit - I've seen them but never worked with one. So I don't know about its capabilities.

In small generators (portables) Honda is the only company I've seen that provides a rating (which is a standby rating in stationary units) and then in the fine print in the specs provides a true prime or continuous power output. Our EM4000SX that we have now, for instance, has a "rating" of 4,000 watts 120/240 and 5,000 watts for 10 seconds. It will indeed deliver that rating, even at 1,100 ft altitude (the ratings are at sea level and standard conditions). However, it will only maintain 4.0 kVA (Power Factor 1.0) output for about 20 minutes at 59 degrees ambient and then the voltage starts to drop because of winding heating. However, if you read in the fine print of the specs it also gives a continuous power output rating of 3.6 kVA (on Honda's website they show it as "3500 watts" which is incorrect - the tag on the generator says 3.6 kVA). We use our Honda for peak load management on our inverters and it will deliver 3.6 kVA for as long as you need it to - and maintain the voltage dead on 240 and the freq on 60 Hz. That's a prime power rating example on a genset that would otherwise be rated at 4,000 watts (at sea level).

My experience with the Generac Guardian and Corepower series of generators is that they are hard pressed to maintain 240/60 even at 50% rated load. They are cheaply built, designed to compete in the market at a price point. That's why they will void the warranty on one if they find out you are using it in an off-grid application. They are ONLY designed for a grid-interactive standby setup to keep your lights on in an emergency. They count on the fact that generators in this type of duty only run for exercise and once in a blue moon during a power outage. And they build them to make it thru the warranty period (hopefully) and then they could care less about whether or not it stays working (try calling Generac's Customer Service sometime and you'll find out what I mean).
--
Chris

ChrisOlson

Re: Choosing a good generator

Cariboocoot wrote: »

1) If your system is sized correctly a 1kW or 2kW generator may well be what you want.

Trust me. The Honda EU2000i is absolutely perfect for my use. That does not mean it is perfect for everyone.

I quoted what I think is important in what Cariboocoot posted - most off-grid folks I know can get by fine with a little 2 kW generator. They will have propane 'fridge, range, etc.. And the inverter only runs light loads that the generator can handle when it's running and charging the bank. So they don't need a large battery bank either (which saves money on batteries in the long term).

Larger off-grid situations will require a larger generator, and many of the folks I know who have larger systems have generators in the 12-14 kW range (usually diesel).

I'm a proponent of inverter/chargers that have generator load support for larger off-grid systems so you don't NEED a large generator. There are only a couple of options for inverters that have this. But it allows you to run large loads that neither the generator nor the inverter can run by themselves, but together they can. This works out just as nicely for us as Cariboocoot's EU2000 works out for him because it's really easy to keep that smaller generator operating at a load that maximizes its output for the amount of fuel burned. Where with large generators you have to scramble to find enough loads to keep a 12 kW unit running at peak efficiency during battery charging.

Coach Dad said:
3) While you are doing your bulk charge you want to run your other high loads (well pump, vacume cleaner, washing machine etc)

Once you have your batteries up to Absorb again and your high loads done, you turn off the gen and go back to batteries.
So using the above logic, I would want a large generator not a small inverter.

I don't totally agree with this "old school" method because it's incredibly inefficient and requires you to schedule loads to take advantage of the gen run time. After you've lived off-grid for 10 years or more, there comes a point where convenience is nice too. And that's why I'm a fan of the inverter/chargers with gen support - they allow you to run anything you want, whenever you want. And if it has to start the gen for battery charging it's as efficient as Cariboocoot's smaller setup (kWh/gallon of fuel burned) - providing everything is sized right.
--
Chris

pHredd9mm

Re: Choosing a good generator

Anyone compare Honda inverter generators to Yamaha inverter generators?

2manytoyz

Re: Choosing a good generator

pHredd9mm wrote: »

Anyone compare Honda inverter generators to Yamaha inverter generators?

Both are excellent. Quiet, sip fuel, and work well in their rated capacity ranges. The waveform output is cleaner than the grid.

The reason I picked a Yamaha over a Honda was the Yamaha EF2400iS was intended to start/run a 13,500 BTU RV A/C unit. The Honda 2KW was slightly too small for the task. The popular solution is to buy two Honda 2KW generators, bridge them together, then run the A/C. That ends up being twice the cost of the Yamaha (2 generators + bridging cable).

Two coworkers have the Honda 2KW, another two own the Yamahas. All depends on what you're looking to do with it.

Here's the testing I've done with the Yamaha: http://www.2manytoyz.com/yamaha2400.html

Dave Angelini

Re: Choosing a good generator

swmspam wrote: »

It is established that Honda, Yamaha, and Subaru-Robin generators are excellent but expensive. I don't need an inverter generator because my application is already feeding an inverter (OutBack GS8048 ). I don't need fancy engines such as the Honda iGX because all I need is constant-power bulk electricity (the iGX is good for variable power operation because the digital engine control adapts quickly to changing loads). But I do need a generator that is reliable when I need it. Does the Generac fit the bill?

Not for me or my folks! Their loads are too important to fool around trying to save money. The Honda 6500i runs the oldest XW firmware from day 1 and the 2000i into a transformer is fine also. The Honda inverter series is all I have any experience with. The only thing better is not needing a generator!

mtdoc

Re: Choosing a good generator

2manytoyz wrote: »

. The popular solution is to buy two Honda 2KW generators, bridge them together, then run the A/C. That ends up being twice the cost of the Yamaha (2 generators + bridging cable).
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Personally, for about $700 more (not twice the cost) than one Yamaha ef2400, I like the flexibility and redundancy of having 2 Honda eu2000is. For smaller loads or battery charging needs I can run one. For larger loads, run 2 in parallel with more power output than the Yamaha. And, If one breaks down, I'm still good for most of my needs.

But that's just me. In the end, I agree with others that generators need to be matched to the loads. Either the Honda or Yamaha inverter generators will likely meet the needs of most people's back up power and battery charging needs. For variable loads, their fuel efficiency can't be beat.

inetdog

Re: Choosing a good generator

mtdoc wrote: »

For larger loads, run 2 in parallel with more power output than the Yamaha.

What is involved, in terms of setup, in getting two of the Honda inverter generators to synchronize? Is there a special link cable, or is one configured as the master and the other as a follower?

Cariboocoot

Re: Choosing a good generator

inetdog wrote: »

What is involved, in terms of setup, in getting two of the Honda inverter generators to synchronize? Is there a special link cable, or is one configured as the master and the other as a follower?

Yes there's a link cable. Then you just start one, then the other. There's even a specific "companion" model which has heavier outlets to handle the full capacity of both.

It's a good system, and one of the options I've been looking at for my own system expansion (no decision made yet).

mtdoc

Re: Choosing a good generator

inetdog wrote: »

What is involved, in terms of setup, in getting two of the Honda inverter generators to synchronize? Is there a special link cable, or is one configured as the master and the other as a follower?

If one of the 2 is a Companion model (which has a 30 amp outlet) then all you need is a 2 wire plus ground connection that plugs into the sockets present on the gens. You can buy Honda cables for $30-40 or make your own.

If neither of the 2 is a Companion model, you need to buy a more expensive kit to have the 30 amp outlet. Reliance makes one for $90 or you can get the Honda kit for $200.

Edit - Oops. 'coot beat me to it!

2manytoyz

Re: Choosing a good generator

mtdoc wrote: »

Personally, for about $700 more (not twice the cost) than one Yamaha ef2400, I like the flexibility and redundancy of having 2 Honda eu2000is. For smaller loads or battery charging needs I can run one. For larger loads, run 2 in parallel with more power output than the Yamaha. And, If one breaks down, I'm still good for most of my needs.

I paid $1047 for my Yamaha EF2400iS. It's now discontinued since they came out with a later model with an even higher starting capacity.

The two Honda 2KW generator package with the parallel kit is available for $2139: http://www.wisesales.com/eu2000i-companion-package-honda-generator.html#.UJLIzT0w_ng FWIW, this is the same company that I bought my generator from.

There's something to be said for redundancy, but I could have bought another Yamaha for a $100 more than the Honda ($999): http://www.wisesales.com/eu2000ia-honda-generator.html#.UJLJrD0w_ng

The Yamaha also did the parallel feature:

Attachment not found.

As it turns out, wasn't a popular option. The generator was large enough to run "most" 120VAC appliances solo. Two generators is also twice the maintenance, twice the fuel, twice the noise, twice the weight, and twice the foot print, which is a big deal when space is a premium in the bed of my truck when RVing!

But if two work better for you, awesome! My buddy likes his twin Honda setup too. He has a bad back, and lifting 47 lbs twice is better to him than lifting 70 lbs once. Like I said, can't go wrong with either setup. If you got two generators for $700 more, and the parallel kit, than the $1047 I paid, you got a very good deal!

Cariboocoot

Re: Choosing a good generator

Honda's page about paralleling units: http://powerequipment.honda.com/generators/parallel-capability

My own dilemma centers around 13 Amps from the existing gen being on the light side if I expand the battery bank ('frige coming on would likely cause the inverter to drop the gen if at full charge rate) vs. spending $1200+ to jump up to 26 Amps which is overkill but adds redundancy or spending $2200+ for the 3000 model which has 23 Amp capability (and electric start).
What I really need is 17 Amps.

mtdoc

Re: Choosing a good generator

Robert- The Yamaha EF2400is I've seen have been $1400-1500 (LINK) but I guess that's the newer model (and is not parallel capable). Sounds like you got a good deal!

And - for an example of a generator NOT well matched to the load:
:roll:
Attachment not found.

Blackcherry04

Re: Choosing a good generator

Most weekends during the summer I run a Honda EU2000 on my boat, My buddy has a Yamaha EF2000iS. One thing we noticed is that his is much louder under load with the ECO throttle on. I can run a IOTA 55 amp on the Honda and it's RPM stays a the lowest point and quiet. The Yamaha jumps up to a much higher RPM and is much louder using the same size charger. It's no big deal till your running them side by side at night. Just some Info about them.

unicornio

Re: Choosing a good generator

mtdoc wrote: »

And - for an example of a generator NOT well matched to the load:
:roll:
Attachment not found.

that's good! ... ;-))))
15kvas for only some phones! ... yeah man, is a very good example! ... hehehehe

swmspam

Re: Choosing a good generator

mtdoc wrote: »

Attachment not found.

Uh, I'm guessing a cheap Chinese-made consumer-grade generator with those graphics and overall look. That generator is probably happy with charging a few cell phones. The should charge up while it's still running ...

BB.

Re: Choosing a good generator

For those not into generators--That guy probably burns 1.5-2 gallons of gasoline per hour to run the less than 30 watts of cell phone chargers (probably able to power about 1,000+ cell phone chargers at one time).

A Honda eu2000i (one I like) will power up to 400 watts about 8 hours on 1 gallon of gas.

Gas Shortages May Not End for Another Week... (New York City after Sandy)...

A couple 5 gallon gas cans vs 120-200 gallons of much fuel to run that big guy for ~80 hours (3+ days 24x7).

More links from Drudgereport.com

Fuel scramble...
Some Siphoning From Cars!
'I'm pretty p***ed'...
Troopers deployed to gas stations...
CON ED: 'Vast Majority' Won't Have Power Until Nov. 11...

-Bill

unicornio

Re: Choosing a good generator

swmspam wrote: »

The should charge up while it's still running ...

yeah!...But you do not ask for much more!...;-)