Whole Office Generator Engines 1

[alanny]

I'm looking for a whole house LP gas generator to power my office in case of a catastrophic outage. I'm looking at the GE 20kW system with the Briggs and Stratton Vanguard engine with a five year warranty. I have heard that Honda has the best generator engines and Briggs and Stratton are generally bottom of the line. Opinions? Is this important enough to be the defining factor in my decision? Any opinions on GE generators versus other makers.
Thanks and Happy New Year,
Al

 

[BrianPetersen]

No idea about generators that large, but in a racetrack-paddock environment, the Honda EU2000i gasoline-fueled portable generator is top-notch, with the Yamaha equivalent as a good competitor to it. A lot of the cheaper competitors are junk and don't last.

A number of my fellow motorcycle roadracing competitors got bonus points from their wives last winter when there was a power failure for several days following an ice storm, and their portable generators came to the rescue.

20 kW is ten times the capacity, though, and may be in a different league.

 

[catserveng]

From my point of view unless you are pretty handy with installing and maintaining a standby generator on your own, your best first question might be "who in my area has the best product and local support?"

In my experience with small generators in this range, Generac is probably one of the better choices as they provide entire packages and usually have pretty good service support.

Also, is your fuel choice driven by what you have on site, or something else? Personally I have found that LP (propane) systems in general to have about the lowest reliability in all types of standby systems I have dealt with, mainly over fuel system issues, this seems especially worse in cold climates. Depending on where you are and what kind of conditions trigger your need for standby power, you may want to consider other options.

I have had only one direct experience with the GE unit, is was installed by a local contractor working thru Home Depot, it was marginally sized for the site load and the priority system had some issues causing some instability. The short term cure was to shutoff some of the loads while on generator, and did hear what the "final" fix was.

Hope that helps, Mike L.

 

[dpc]

I would look at Generac as well. Residential-grade systems will be lighter-duty than a true commercial-grade system. You get what you pay for to a large extent. The engine is the the most likely thing to fail. In an installation such as yours, most problems are related to failure to start and then overloading. If the engine sits around for months or years without being started and run under load, it may not start when you want it to. Periodic starting and loading is important for these systems.

My advice is find a reputable dealer/contractor and ask a lot of questions. Also, I assume you realize that you will still experience a short-term power outage while the engine is cranking and loading up. Some type of UPS will be needed to ride through this downtime.

 

[alanny]

In answer to some of your questions.
I'm using LP gas because that's what I have now for heating and hot water. I also have heard that LP/natural gas engines run cleaner.
Most of the automatic-on generators in this area seem to run on LP/Natural gas.
I have been talking with reputable contractors.
The GE system was part of an overall quote/package I received from a second contractor. If I go with his firm they will service it.
These automatic units turn themselves on once a week as a self-test.
As a computer person I always use a UPS, for clean electric to important components as well as getting through brown outs or brief electricity outages.
One contractor said that Honda motors were the best, Kohler after that and Briggs and Stratton below that. Thus my concern over engines.
Thanks,
Al

 

[waross]

Fuel: LP gas; is that propane or butane? Lp gas tends to be propane in the north and butane in the south. As the temperaturs drops the pressure of butane drops much faster than propane. Unfortunately power outages sometimes occur during periods of unusually cold weather. You may experience low fuel pressure issues during cold weather. Natural gas has a different problem but the a similar result. During very cold weather the natural gas usage tends to be heavy and the mains pressure drops. Tis effect may lead to low fuel pressure issues with natural gas also.
I have had to arrange no-voltage lock-offs for air conditioners to avoid all the A/C units trying to start at once and stalling the gen set.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[alanny]

Bill,
We have propane.

 

[DanEE]

The vaporization issue is well understood and can be factored into tank size selection by a competent system designer.. Information is available for various tank sizes to compute the attainable withdrawal rate over time at given ambient temperatures before auto refrigeration sets in... If a system is vapor fed, then the storage tank (where the phase change occurs) needs to be large enough (thermal mass and heat transfer surface) to provide the required flow rate for the lowest temperature expected without the LP liquid and tank temperature dropping too low.

In systems with smaller LP storage capability such as a trailer mounted Miller Welder/8.5KW generator that I have, the factory optional LP powered engine is a wet LP feed system. This system was designed by Miller to use "fork lift" style LP tanks (with a dip tube to draw LP out in liquid form) and uses engine heat via an LP vaporizer attached near one of the air cooled cylinder heads for liquid to vapor phase conversion.. In addition to LP powered fork lifts, vehicles using LP fuel will typically use the same type system. NFPA gas codes in the USA are far more stringent for liquid feed systems and where they can be installed.

As waross mentions, butane presents more of a problem with auto refrigeration than LP.. All my comments are based on "LP" propane experience ..

Propane or Natural Gas is preferable for many business commercial property owners because they do not want the liability of a diesel fuel spill on their properties. One of the first things we would have the natural gas company certify as part of their pricing of the metering and gas plumbing for a commercial environment generator installation, was that their system could support the gas flow requirements. That might be dicey in a residential area.

 

[alanny]

Great answers. I have a good place to start now.
Thanks,
Al

 

[OperaHouse]

I wouldn't want to be your neighbor with that B&S engine, they are loud compared to other makes. There is an operating cost to these. It will use a full tank of propane a year just doing the weekly tests.

 

[davidbeach]

If it doesn't get loaded during those weekly tests they may ultimately do more harm than good. I'm not familiar with the gas fueled engines, but that would definitely destroy a Diesel if it never gets thoroughly hot.

 

[danw2]

I don't know where Kohler gets its reputation. I spent a college summer repairing golf course equipment and the equipment with a Kohler engine sat there with broken cam shafts from when I arrived until I left; not because I couldn't fix 'em but because Kohler was unable to supply replacement cam shafts.

Fast forward twenty years, neighbor borrows another neighbor's rototiller. He uses it for a couple hours and it quits dead on him. He asks me to help out. The magneto produces a spark. So I shoot ether down the carb. Not a sput nor a sputter. Huh? Ether HAS to burn. I pull the plug, it sparks. I put my thumb over the spark hole and pull the recoil starter, no compression. Peer into through the spark plug hole, the intake valve never lifts, the cam shaft had broken. Of course, it's a Kohler.

Fast forward another decade, different neighbor's riding mower dies in the middle of the yard. Same deal, it sparks, but no sput, no sputter, no compression. Yup, another Kohler broken cam shaft.

I've avoided Kohlers like the plague figuring anyone can make a mistake, but what sort of outfit can't fix their mistake over a 30 year period? That many broken camshafts in one man's life CAN'T be coincidental. I do hear Kohler's toilets are great.

I agree that B&S engines are loud. Whether a stationary generator uses the engine's factory spark arrestor or a a different brand muffler might be a question to ask.

 

[itsmoked]

Kohler's toilets are great

Not really..

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

I have a Vanguard-engined generator for when the utility fails. When we first moved here outages were a weekly occurence, although rumour from friends who work for the utility has it that there was a problem with the protection relaying. These days thinsg are reasonably stable for an OHL supply.

The B&S one-pot engine is very noisy! It also has a primitive governor and the frequency regulation isn't exactly tight under load changes which might be a problem for the UPS you propose to use. My APC Smart UPS1400 doesn't happily operate on the generator unless there's an additional load. The voltage regulation from the Sincro tail end is pretty good, although it has an aftermarket AVR these days. The Generac AVR originally (?) fitted failed and the cost of a replacement is absurd.

 

[dicer]

Briggs & Stratton engines are durable, engine noise is the fault of the enclosure and exhaust system. The thing to do is find some generator dealers in your area and talk to them. And maybe even a good electrical contractor they may have some experience installing gensets and have some advice. If you plan to run a whole house hold on a genset you need someone that can figure out what the loads are going to be so the genset can be sized properly.