Choosing a good generator

IYAPYSNF · September 2014

Re: Choosing a good generator

Why makes the Smarter Tools junk?

BB. · September 2014

Re: Choosing a good generator

So far, it has been past history from Costco... Even if the engines last, there have been past problems with carburettors, switches that fail, and weak components in the generator drive (plastic in the Generic series).

The last 2kW suitcase model was "Honeywell" branded. Worked fine at first for several people, then more and more problems (hard starting and electrical front panel switch failures?)--And there may have been a mechanical exchange for some folks. A couple of threads:

Generac IX2000 review
Generator questions

Of course, the above probably does not apply to the new 2kW suitcase from Costco... However, it does give one pause to buy an unknown/no history genset from Costco.

Costco does stand behind their product very well... However, if this is for an emergency situation (pickle the genset, pull from storage, add gas, pull rope, hopefully run), there is always the concern that it has problems when you needed it.

If you were going to purchase one to use now (portable power, experiment and put a 100-200 hours on genset before setting aside for emergencies)--It is probably cheap enough to experiment with--And Costco should do good by you if it has problems.

-Bill

IYAPYSNF · September 2014

Re: Choosing a good generator

Costco has a 100% refund policy, I know, I work there. I doubt very much Costco is the reason these generators receive bad reviews.

What I would be very interested in is how the components compare to say a Honda version. Plus, the ST 2k inverter from Costco has a Yamaha motor in it, same at the Yamaha 2k inverter I believe. So in regards to motor quality it is on par with Honda a Yamaha. The inverter quality is really the unknown with these off name guys and I wish there was a detailed way to find out where the inverter components come from and are manufactured.

BB. · September 2014

Re: Choosing a good generator

With world wide mfg and sourcing--It is difficult to tell if the quality is good or bad, or even if it has changed over time.

Many times, a factory would contract to make the "brand name product", then start selling "knockoffs" (of variable quality) out the back door shortly thereafter.

Too many low cost generators seem to pass 100 hours OK, but not work long after. Somebody getting a genset for a storm, may only put 100 hours on a genset over years of (non-)use (something like 5 hours x 20 days of use).

-Bill

oil pan 4 · September 2014

Re: Choosing a good generator

IYAPYSNF wrote: »

So in regards to motor quality it is on par with Honda a Yamaha.

Only if they fixed all the massive design flaws.

Arkansasoffgrid · October 2014

Re: Choosing a good generator

Anyone installed a "tri-fuel kit" on their Honda EU2000I, if so whats your opinion of the system. Just ordered one, since we will have a 1000gal propane tank that seemed a better idea than trying to cycle fuel cans.

vtmaps · October 2014

Re: Choosing a good generator

Arkansasoffgrid wrote: »

Anyone installed a "tri-fuel kit" on their Honda EU2000I, if so whats your opinion of the system.

I haven't tried one. In my research I learned that it voids the Honda warranty. The engine has lower horsepower on propane resulting in the derating of the generator wattage. You can adjust it to bring it back to full power, but that makes the engine run hotter.

Lots of folks seem to be doing it, but there have been a few sad stories over on the yahoo honda forum. Of course, there are also some sad stories about non-converted hondas.

--vtMaps

mike95490 · October 2014

Re: Choosing a good generator

I've also heard propane conversions eventually screw up the intake valve stem, from no lube. (that's what some of the gasoline additives do)

jcheil · October 2014

Re: Choosing a good generator

mike95490 wrote: »

I've also heard propane conversions eventually screw up the intake valve stem, from no lube. (that's what some of the gasoline additives do)

Leaded gas was the best lube your engine ever needed. Those motors back then lasted forever (the top end at least).

And on the topic of generators, i've had my new Honda EU7000is for just about 3 weeks now and it is AMAZING. Well worth the $3900.
Fuel injection, remote start, and amazingly quiet. But, I haven't really needed it yet

I actually just ran it non-stop for 20 hours to break it in and it didn't even use a whole tank of gas in that whole time

I remember someone here once said "The best plan is to buy the best generator you can afford and then try not to use it".

oil pan 4 · October 2014

Re: Choosing a good generator

mike95490 wrote: »

I've also heard propane conversions eventually screw up the intake valve stem, from no lube. (that's what some of the gasoline additives do)

That is why I run a little bit of 2 stroke oil. Shindowa red armor, at some where around a 100:1 mix.

Sakamochi · November 2014

48 Vdc or 120/240Vac?

I'm trying to decide what is the better strategy for a generator: Looking at Kohler 6VSG vs 8.5 Kw res. DC sounds good because the Inverter charger wouldn't be required (my logic). BUT the ac version has the plus of being able to run the 240 vac well pump when needed. $5304 vs $3559, both propane. Pros and cons, experts???

The system is about 8 years old. The original 16 Trojans crapped out in 2011. The 16 replacement Rolls boiled out this past July (they were fine 3 weeks prior, running 114 f hot per rolls set point of 4 hrs absorb@59.2v). Rolls said it was my fault somehow and no warranty. I take care of my batteries like firstborn babies, SG reads, never taken down to 48v, auto exhaust fan, temp monitors, ad infinitum. After $16,000 in battery cost, I think I just need to get reliable charging to keep the new Interstate L16s in good shape.

Appreciate any (good) advice.

Cariboocoot · November 2014

Re: 48 Vdc or 120/240Vac?

Note: all generators are in fact AC. A DC gen simply is rectified to DC.

Question: what is the output Voltage of the DC gen and how would you regulate the charge? Do not expect to feed it into your charge controller; it won't work.

Comment: Surrette always thinks their battery failures are the user's fault. You won't see me recommending them anymore.

Sakamochi · November 2014

Re: 48 Vdc or 120/240Vac?

Cariboocoot wrote: »

Note: all generators are in fact AC. A DC gen simply is rectified to DC.

Question: what is the output Voltage of the DC gen and how would you regulate the charge? Do not expect to feed it into your charge controller; it won't work.

Comment: Surrette always thinks their battery failures are the user's fault. You won't see me recommending them anymore.

The Kohler 6VSG is either 24 or 48 Vdc, 111 amp maximum output. I would use 48 v. I'm guessing at this point from your msg that you say that the Outback cannot work with a generator? I had originally thought that the Outback would do the sensing and charge regulation, in leiu of solar panels. From what I have read, the Kohler is capable of sensing, self start, charge set points. I haven't read the spex just yet on the 6VSG. For the 8.5RES AC gen, the Xantrex would perform charge control as I know it can do the job due to using my 4800 watt Honda gas generator in that way. My solar service guy said that the Xantrex is not "the best charger".........

Thanks again

Cariboocoot · November 2014

Re: 48 Vdc or 120/240Vac?

MPPT charge controllers are meant for PV input, which is entirely "pure" DC; any rectified AC source is going to have distortion in it which will affect the controller function. The best bet for such an installation would be a controller design to handle wind turbine output. The MidNite Classic would be better suited to this than an Outback FM series.

Another point is that the DC source Voltage is meant to be at 'Vmp level' or above. That would be 35 Volts or more for a 24 Volt system, 70 Volts or more for a 48 Volt system. If the generator's output is regulated at 48 VDC +/- 'X%' it would work for a 24 Volt system but not for a 48 Volt (Voltage too low). Also the 111 Amp output could fry an 80 Amp controller under certain conditions. As such the gen should be 'preloaded' so that the current available to the controller can't exceed it's maximum (with tolerance factor) and of course over-current protection installed just to be sure.

On the whole it's easier to use the AC gen and an AC charger such as the one built in to the inverter.

techntrek · November 2014

Re: Choosing a good generator

Arkansasoffgrid wrote: »

Anyone installed a "tri-fuel kit" on their Honda EU2000I, if so whats your opinion of the system. Just ordered one, since we will have a 1000gal propane tank that seemed a better idea than trying to cycle fuel cans.

When I moved into my house it already had a 500 gallon LP tank. Installed a LP genset. I wouldn't go that route now and would prefer to just cycle the gasoline that runs a much more efficient inverter-genset. Partly because I've now dealt with the company that owns that tank for 10 years now, and their only goal is to see just how much above the regional average they can charge before you complain. In the past they would adjust it, but in the last 2 years they always have some excuse why they can't (ever since company X was bought up by company Y). Now I can run most of the house for $12 a day instead of $120 a day, so the LP genset gets little use.

Edit, it just sunk in that you will be running an inverter-genset... but getting locked into one LP company is still a worry.

gww1 · November 2014

Re: Choosing a good generator

Tech

but getting locked into one LP company is still a worry.

I just bought a tank to get rid of that worry.

gww

Sakamochi · November 2014

Re: 48 Vdc or 120/240Vac?

Cariboocoot wrote: »

MPPT charge controllers are meant for PV input, which is entirely "pure" DC; any rectified AC source is going to have distortion in it which will affect the controller function. The best bet for such an installation would be a controller design to handle wind turbine output. The MidNite Classic would be better suited to this than an Outback FM series.

Another point is that the DC source Voltage is meant to be at 'Vmp level' or above. That would be 35 Volts or more for a 24 Volt system, 70 Volts or more for a 48 Volt system. If the generator's output is regulated at 48 VDC +/- 'X%' it would work for a 24 Volt system but not for a 48 Volt (Voltage too low). Also the 111 Amp output could fry an 80 Amp controller under certain conditions. As such the gen should be 'preloaded' so that the current available to the controller can't exceed it's maximum (with tolerance factor) and of course over-current protection installed just to be sure.

On the whole it's easier to use the AC gen and an AC charger such as the one built in to the inverter.

Fyi The Kohler 6vsg has a programmable output connected directly to the battery bank. Set point could be as high as 70vdc, however it would likely be set at the bulk/absorb level. The current is limited by voltage set (va) so overamping is not possible as the generator is the charge controller itself.

I have hired a reputable company with hundreds of off grid generator installations. I'll update what comes of DC vs ac after I get their recommendation and quote.

Thank you for all the information and guidance, I really appreciate this forum!

Blackcherry04 · November 2014

Re: 48 Vdc or 120/240Vac?

Sakamochi wrote: »

Fyi The Kohler 6vsg has a programmable output connected directly to the battery bank. Set point could be as high as 70vdc, however it would likely be set at the bulk/absorb level. The current is limited by voltage set (va) so overamping is not possible as the generator is the charge controller itself.

I have hired a reputable company with hundreds of off grid generator installations. I'll update what comes of DC vs ac after I get their recommendation and quote.

Thank you for all the information and guidance, I really appreciate this forum!

Could you show us where the 70v is at ?? All I see is 54 v dc.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CCYQFjAB&url=http%3A%2F%2Fwww.kohlerpower.com%2Fonlinecatalog%2Fpdf%2Fg4213.pdf&ei=8yZZVMKNMYiwyQT3vIGYBg&usg=AFQjCNFhd4NxilIS9DOG4AQq-D6gaa3AvQ&bvm=bv.78677474,d.aWw&cad=rja

jcheil · November 2014

Re: 48 Vdc or 120/240Vac?

Sakamochi wrote: »

Fyi The Kohler 6vsg has a programmable output connected directly to the battery bank. Set point could be as high as 70vdc, however it would likely be set at the bulk/absorb level. The current is limited by voltage set (va) so overamping is not possible as the generator is the charge controller itself.

I have hired a reputable company with hundreds of off grid generator installations. I'll update what comes of DC vs ac after I get their recommendation and quote.

Thank you for all the information and guidance, I really appreciate this forum!

My opinion is go with an AC generator. Because if something goes wrong with house power at least you can run DIRECTLY from an AC generator.

Uncle Dave · November 2014

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?

I'd put generac portables at pretty close to the bottom of the generator barrel.

Same as their RV units.

I've only owned one generac product and that was enough.

Take a look at the maintenance schedule, they are calling for a valve lash adjustment every 100 hours. This is a testimony to the materials used in the engine and its expected duty cycles.

Typical Yamaha/Honda/ Robin/Subaru valve inspection and lash adjustment interval is 250- 300 hours or 3 times the interval generac calls for in their portables.

I know this info is not what you were hoping to hear.

Sakamochi · November 2014

Re: 48 Vdc or 120/240Vac?

Page 34 of the operation manual states 54 v is default, however can be set higher. I estimated 70v max from the graph. Obviously amps would be unusably low at higher voltage output.

Generator installation company recommends 120/240 vac either generac ecogen or Kohler 14RESAL or 8.5 RES. They are figuing amps and such and will have a firm quote tmw. They warned of poor warranty and customer service for Generac from outside US although some customers wanted the general and were happy. They prefer Kohler. Prices are about same.

They said 6VSG is not for me as the xantrex is incompatible. Great inputs here, so will be going Kohler 120 v unit coupled with Xantrex charger. They are going to put a 240 v manually switched output for my well pump. I would like an autofill switch on my 3000 h20 gallon tank but learned long ago to unplug my pressure pump when away for extended times. One time a leak sprung loose in February below zero and the pump ran til the tank emptied and then ran til killed the battery bank low battery v trip out. Luckily my neighbor happened to checkup and saved freezing pipes

This is a great forum! Thanks!

Anawa · November 2014

Re: 48 Vdc or 120/240Vac?

Curious, why does the gen installation co. recommend the Kohler RESAL @ 14kW and the Kohler RES @ 8.5 kW? I am about to pull the trigger on a comparable RESAL unit and apparently there is a major difference in the two models. Thanks.
Anawa

BB. · November 2014

Re: 48 Vdc or 120/240Vac?

Anawa,

What are your power needs? If your loads are less than ~4-7kWatt continuous, the smaller genset can use about 1/2 the amount of fuel as the larger genset.

More or less, a standard gasoline/petrol/propane genset will be "fuel efficient" at 50% of rated load or higher. At less than ~50% rated load, the fuel flow (gallons per hour) remains roughly fixed... So, if your genset uses 1 gallon of fuel at 50% of load, it will still use ~1 gallon per hour at 25% or 0% of rated load.

For diesel gensets, in general they are usually recommended to run at ~40-60% minimum load. If you run them below minimum load for long periods of time, they can "wet stack", build up carbon in the combustion chamber, and/or glaze the cylinder walls (loss of compression, burn oil).

So, regardless of the differences between the two units--What are your long term power needs?

-Bill

Anawa · November 2014

Re: 48 Vdc or 120/240Vac?

B.B. I now think that the 8.5 kW RES and the 14 kW RESAL are "classified" by Kohler as an off-grid units. I have been looking into Kohler 8-10 kW RESVL units for myself, but believe that they are not off-grid units according to Kohler.

After posting a preliminary design on the forum a couple of weeks ago, I have finalized a 4.5 kW array with an Outback FP-2 FX3648 unit. And, settling-in on a 700 ah battery bank (industrial forklift) and shopping for a genset. My calc's reflect that my inverter load could max-out at a little less than 7kW.

Still looking for expert advice from the forum contributors.

oil pan 4 · November 2014

Re: 48 Vdc or 120/240Vac?

BB. wrote: »

For diesel gensets, in general they are usually recommended to run at ~40-60% minimum load. If you run them below minimum load for long periods of time, they can "wet stack", build up carbon in the combustion chamber, and/or glaze the cylinder walls (loss of compression, burn oil).

I have seen 1800rpm 6.5kw 3 cylinder Kubotas with thousands of hours running less than 2kw load.
None burned excess oil.
The big 70kw 400Hz generators I work on run at 5kw or less pretty much all the time. Only the 2 stroke Detroit diesels burned oil, because they are historically known as oil burners, these particular ones had been improperly rebuilt several times by the lowest bidder. The new generation of 4 and 6 cylinder Cummins have yet to burn much if any oil and get ran the same way.

I say get something that turns at 1800rpms, liquid cooled, gas or diesel. 1800RPM generator sets (4 pole generator) will be a lot quieter and burn a lot less fuel than a 2 pole, 3600rpm screamer.
Liquid coolant means you can pipe what other wise would be waste heat some where and actually do something with it, especially during the winter.

Cariboocoot · November 2014

Re: 48 Vdc or 120/240Vac?

oil pan 4 wrote: »

Only the 2 stroke Detroit diesels burned oil, because they are historically known as oil burners,

Gee, imagine that: a 2-stroke engine burning oil.

techntrek · November 2014

Re: 48 Vdc or 120/240Vac?

;)
...................

Ken Marsh · November 2014

Re: 48 Vdc or 120/240Vac?

Coot, The Detroit diesel Oil Pan refers to did have wet sump or oil in their crankcase.
They achieved their scavenging with a blower.
These engines were made by the million but they are gone now.
The most popular were the X-71 series.
The X was the number of cylinders and they had 71 cubic inch per cylinder.
They burned oil but usually leaked more than they burned.

Any diesel that can meet today's emission standards probably will not be wet stacking.
But the old ones sure did.
We have a 50s vintage Continental on a generator.
We do not use it to do equalization because it may wet stack.
But its great for bulking.

Cariboocoot · November 2014

Re: 48 Vdc or 120/240Vac?

Ken Marsh wrote: »

Coot, The Detroit diesel Oil Pan refers to did have wet sump or oil in their crankcase.
They achieved their scavenging with a blower.
These engines were made by the million but they are gone now.
The most popular were the X-71 series.
The X was the number of cylinders and they had 71 cubic inch per cylinder.
They burned oil but usually leaked more than they burned.

Yes, I know. It was a joke.

techntrek · November 2014

Re: 48 Vdc or 120/240Vac?

.... since all 2-stroke engines burn oil by design ...

Choosing a good generator

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