I know there are a few out there that will agree. Stay away from GenerCrap.

Generac are a LOT better than they used to be.

Weigh the options and stats (such as warranty) and see what you think.

This is a long standing question also. Do a web search and you'll find tons of forum threads on exactly this.

Recent comparison had Kohler 8.5 RES-QS7 way ahead of Generac CorePower 5837 in power quality. power delivery and noise. Cost is MUCH higher, however.

I probably don't understand enough about the working of generators to understand the differences but I did see Generac is a 3 y warranty and the Kohler is 5 years. Our Sentry pro is only 6 years old and the stator is dead. The honda engine in it still runs but doesn't produce electricity. The cost to repair is about $3000 so it seems like replacing is a better option. The wiring and propane plumbing was all done in 2008 when we bought and moved it.

Poor power quality can cause overheating of motors and failure of electronic equipment. I can't really saw what is good enough.

Sorry, I meant "I can't really SAY what is good enough" rather than "saw".

ionized , interesting you say poor power quality can cause failure. I actually saw it happen. Apparently the power went on and off 2-3 times, last time staying off. Our generator went on, within a minute I saw a light go out but heard the generator. Thought we blew a bulb. No, apparently stator died, though the generator continued running it was not powering enough to give electricity.

I was referring to poor power quality from the back-up genset. That can cause premature failure of electronic and electric motor loads.

? Genset? meaning the generator itself?

genset = short for 'generator set'.

LOL. Even if they're really alternators. Or are they generators these days, and converted to AC?

Thank you. We are leaning toward the Kohler because of the longer warranty. Do want to check one thing I read on a thread - If not installed & start up by a Kohler rep you void the warranty. We have someone that said once it is here he will look it over and if it is an easy switch from ours he could do it. If not there is a Kohler supplier a couple towns away.

Not true about the warranty.

I installed one last fall, but it had problems this summer. The warranty department dealt with the customer and then me in a very helpful manner.
Nothing was questioned about the install. As long as it is done correctly and documented properly.

Thank you Petey, just something we were going to look into.

I expect that soon there will be a lot more inverter gensets. I suspect that change is somewhat fueled by the development of inverters for renewable power production. A lot of the technology should be transferable. Right now there is still a lot more economy of scale in favor of the traditional types but with any kind of luck, we will reach the tipping point for inverters soon.

There are a lot of advantages including greater fuel efficiency, lower noise, longer engine life, lower weight, the ability to increase capacity in a modular manner with syncing inverters, and cleaner power. We are already seeing the inverters move to more manufacturers and up in size.

Hi,

A quick, tough not neccesarily always good, measure of quality of a generator is to look at the weight. The more the thing weighs the better. Why?

Many things make a generator good, but in essence more copper wiring, or thicker copper wiring means less resistance and stronger magenetic fields. Also more weight means more inertia, especially rotational inertia to help when large motors kick in.

I would therefore simply look at the specifications and look in the weight of the generator. The heavier ones will in general be the better quality products, and also the more expensive.

Also water cooled car based engines are better than air cooled lawn mower based engine based gensets. RPM wise look for ones that spin at 1,800 rpm vs 3,600 rpm. Not there is a big jump in price between water cooled and air cooled. The cost difference of approx 2x comes mostly in instalation costs. Air cooled means light. Does not need a concrete pad, and does not need heavy lift e.g. crane to install.

Good brands for top end are Kohler and Cummings Onan but they are expensive.

Best, Mike.

With old-school generators a good one will certainly be heavy. Heavy ones are not necessarily good. Inverter-based equipment should be lighter.

Hi,

Inverter gensets are nice. The best one I know is the Honda EU6500iS. This is a petrol unit and costs $US 4,500 approx. It is however only 6.5 kw power output. The reason for inverter is that the generator can run at the optimum speed and the electronics guarantee a 60 Hz output.

The down side of this is that the power electronics, mainly because of cost, are limited to the smaller power outputs.

I think the original poster was looking for something in the 12KW to 15Kw power range. I do not know of an inverter generator in that sort of power range.

Best, Mike.