The Survival Podcast Forum

Energy Options => Other Energy Sources => Topic started by: Citizen Zero on August 13, 2018, 10:36:31 PM

Title: Some wisdom on Backup Generators, Lessons Learned from Experience
Post by: Citizen Zero on August 13, 2018, 10:36:31 PM
Lesson #1 – If you don’t spend the money on quality the first time, you are going to spend more on a replacement or even worse you are going to be left in the dark when you need it most.

Lesson #2 – See Lesson #1

Generator Fundamentals in a nutshell, PLEASE research for yourself in better detail than I am going to provide here. I’ve done tons of research and reached my own answers, they may not be the answers for you.

Gasoline/Propane Powered: typically 5-6KW 3,600 RPM units with 8-10HP single cylinder engines and brush based generator heads. Fuel inefficient, fuel stores 1 year max, NOISY and provides ‘dirty’ sine power (bad for your electronics). ‘Surge Ratings” are generally measured in SECONDS, not minutes.

Diesel Powered: a plethora of 6-7KW 'silent' 1 cyl units out there that run at 3,600 RPM, gen heads may vary but are usually brush based (not as common as it is in gasoline units). Some multi cylinder units are available in 1,800 RPM, but there are fewer offerings and they are more costly ($2,500+). May be brush based or brushless (the latter provides clean sine power). “Surge Rating”  +/- 2 min.

Now to my situation. Back in 2008 I bought a Yanmar clone 3 cylinder diesel generator that runs at 1,800 RPM that produces 12,000W (12KW) at 240VAC. I was proud at first and figured 'I had it all covered', well at least for the first six years, when it faithfully powered everything in the house and then some. At the six year mark the first voltage regulator had to be replaced, a year later the second one. After replacing both we were still left with flickering lights in the house unless we found extra load (4.5KW of space heaters) to appease the Chinese generator deity to make the lights stop flickering. Then, a couple of weeks ago the engine controller went bad as well and we were left with a generator that decides to terminate fuel flow to the engine after about 40 seconds of run time for no good reason.

Fine, "I’ll replace it" I said. Not so easy as one thinks. The part is only $80, but it only can be ordered from China. Not good. Buying a ‘clone’ was not the smartest idea in the first place, but the price was right and it did the job (in the beginning).

So here I am again, basically back at the beginning (aka: spending more).

Solution: After quite a bit of research and shopping I settled on a US Military MEP 802A surplus generator. Yeah, it is only ‘rated’ for 5,000W (5KW) at 240, but in reality they will do sustained “surge” up to 7,500W (7.5KW) for more than an hour (not minutes) – (load bank tested prior to purchase).

We brought one home for under $2,500. Needless to say I was more than impressed with its performance. 1,800 RPM operating speed and it handily powered the entire house without breaking a sweat. Unlike the Chinese gennie we still have, you can independently adjust voltage and frequency right from the front panel to ensure that all is well with what is being fed to your house (including CLEAN sine power).

Bonus is that the MEP 802A is dramatically quieter than the current generator we are 'retiring' and can be silenced even further by adding a secondary muffler for combustion noise (1 ¼ NPT threaded exhaust outlet). One other bonus, fuel usage under full rated load is right around 1/2gal per hour. Did I mention 100% AMERICAN MADE!!

The US Military generators can be had at reasonable prices and are a solid investment when to comes to backup power needs. Just remember that they are all severely underrated when it comes to their true capabilities, the US Military does not mess around when it comes to the gear that protects and supports our troops.

Sorry for the long post, and as always, just my $.02
Title: Re: Some wisdom on Backup Generators, Lessons Learned from Experience
Post by: Citizen Zero on August 13, 2018, 11:28:43 PM
Something crucial that I forgot to put in the post, that deals with Mean Time Between Failure (MTBF).

Your typical Big Box generator has a MTBF of 500 hours or less run time even when properly maintained (typically total failure of the engine).

Typical MTBF on Military units and 'Prime' rated units is somewhere around 2,500 - 5,000 hours run time if maintained properly.

Again, just my $.02 (I think I am broke now).
Title: Re: Some wisdom on Backup Generators, Lessons Learned from Experience
Post by: FreeThinker on August 14, 2018, 12:36:30 PM
I just jinxed myself, I know it...


2006 9kW Coleman Powerstation, Honda GX 6x0 V-twin engine, propane.  Only full synthetic oil, changed every 60-80 hours and new filter every 3 oil changes.  The oil is more carmel colored than black when I change it, and I reuse that for chainsaw bar oil.  Not sure if it made a difference, but I use a balancing transformer to balance the load across both legs (L1-N-L2) and rarely run it over 75% of the rated max amps.  No idea what I'll replace it with when it dies since these aren't made any more, but it will be one with a Honda engine.  I've owned 4 generators in my life, and the 3 that have Honda engines are all still running - this one has the most hours on it but the other two (portables) are from the mid-90's and still start/run like new.

Best of luck with your new one CZ, may she give you many, many years of reliable and trouble-free use.
Title: Re: Some wisdom on Backup Generators, Lessons Learned from Experience
Post by: Citizen Zero on August 14, 2018, 08:24:13 PM
Hats off my friend, seeing that number of hours on the panel is impressive. Your choice of fuel, more than regular maintenance and avoidance of overloads is probably what got you there.

I have seen many deaths of the big box generators over the years as well as done a ton of research that brought me to my conclusions that I put in the initial post on this subject (as always jut my observations from my experiences). There used to be a great site out there that covered all the pro, cons and a plethora of other information on backup generators (including the little known ground loop hazard), but unfortunately it disappeared several years back.