[TowerTalk] Low RFI diesel generator?

[Grant Saviers]

Many of the home backup gens here are 3600 rpm, not a bad compromise IMO 
considering the very low duty cycle.  However, when I bought my Kohler 
the advice was to not go 3600 as the very low loading on the engine 
during the weekly test/exercise cycle frequently causes cylinder glazing 
and that leads to high oil consumption.  So I ended up with a larger gen 
(40kw) than I wanted at 1800 rpm.  1200 and 900 rpm gensets are 
available for continuous duty and last nearly forever.  I talked to a 
mechanic in Bora Bora who had a pair (100kw?) running for 15  years 24/7 
with only injectors replaced.

I use propane (1000 gal tank) as fuel as diesel is tricky to store for 
long periods.  In the US, the environmental codes for any useful gallon 
quantity require double tanks and special permits, a hassle and 
expense.  A little moisture (tank condensation) and you get bacterial 
growth.  I had a boat with 750 gallons on board and periodic pumpouts 
and filtering were needed in warm climates if the fuel wasn't used.  
Also the cetane rating deteriorates with time. Propane (or natural gas) 
is the cleanest least hassle least wear fuel, and propane is stable for 
long term storage with no maintenance. Natural gas might not be 
available in certain disaster situations.

As for RFI, none noticed from my spark plugged Kohler which is 50' from 
one tower, but I've heard that the newer diesel electronic injectors in 
light trucks can cause RFI in mobile applications.

As a suggestion, if diesel power is a must, you might ask the marine gen 
dealers/installers/mechanics near you for some advice, they all need to 
be RF quiet.  Some other marine/commercial brands - Northern Lights, 
Caterpillar, Kohler, John Deere.  Larger Onans are Cummins/Onans.   
Detroit Diesel makes bigger ones. Huge numbers of the legendary 71 
series diesels (2 to16 cylinders) powered gensets in all sorts of 
applications and are available surplus.

Grant KZ1W


On 3/26/2013 6:45 PM, Rick Kiessig wrote:
> I'm in the market for a new genset - probably a low-RPM diesel generator,
> with 240VAC, clean sine wave output, audibly quiet / "silent" canopy, in the
> 10 to 20 KW range. It will be located fairly close to my radio equipment, so
> I'm particularly interested in finding one that won't also create a bunch of
> RFI.
>
>   
>
> Reliability is key. Low fuel consumption is also important. I may end up
> adding a transfer switch to have it run my home in the event of a power
> failure, along with an external fuel tank to increase maximum run time to
> about 14 days.
>
>   
>
> I'm currently looking at Cummins, Kubota, UK Perkins and Lister Petter. I
> would appreciate any recommendations for brands or models that you've found
> to be good, as well as ones to avoid.
>
>   
>
> Thanks and 73,
>
> Rick ZL2HAM
>
>   
>
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