Jay, Other than the two items mentions, lower BTU's and altitude derate, I know of no other reason for LP to have lower output. If it is in the budget, I always oversize a generator after derating so it does not operate above 70% load. I do this for longer engine life as I imagine a fully loaded engine will have a much shorter life.
Larry Crutcher Starlight Solar Power Systems On Jan 30, 2013, at 2:38 PM, Jay Peltz wrote: Hi guys Right on all accounts but I continue to hear that propane/nat gas is further derated than the liquid fuels. Or is this just bad info? Thx Jay Sent from my iPhone On Jan 30, 2013, at 12:44 PM, "Larry Crutcher, Starlight Solar Power Systems" <la...@starlightsolar.com> wrote: > Jay, > > In addition to what Dan has said, 1 gallon of propane has about 35% less > BTU's compared to 1 gallon of gasoline. So the propane derating must be added > to the altitude derate to determine generator output. > > > Larry Crutcher > Starlight Solar Power Systems > > > > > On Jan 30, 2013, at 1:32 PM, Dan Fink wrote: > > Jay; > The "standard" seems to be 2-3% derate for every 1000 feet above sea level > for gasoline, diesel or LP gas generators, and supposedly more like 5% for > natural gas. (in general we don't work in areas that have natural gas > service, we only do off-grid). So the propane de-rate for altitude is no > worse than the diesel or gasoline de-rate, it's just added on top of it. In > practice, we are not seeing that big a hit, but it is hard to really judge. > Also, air-cooled generators don't cool as well at high altitudes and tend to > run hot. > > A fairly common troubleshooting call we've seen in the past is clients who > have purchased cheap portable generators from Home Depot, Harbor Freight etc. > and then find that they can't tune them for anything above 6000 feet -- the > carb adjustment screws don't go that far, and the fine print in the warranty > actually says 6000 ft max. Ouch! They run so poorly that very few modern > inverter/chargers will even look at their input. I've been a local > firefighter for 14 years now, even worse problem with chainsaws (2-stroke). > We've learned how to bust out the plastic "EPA stops" on the carb adjust > screws, with the of course unofficial instructions to throw the saw into the > fire if the EPA shows up...... > > Never had the slightest high-altitude issues with the Honda x000i series > running OK, and I have no idea why. The de-rate factor is certainly still > there, but no issues idling or running, no matter what the draw. My Honda > 3000i issues are from a different cause I think; there is an extensive thread > on that in the archives here that I started in July 2011 I think. > > DAN FINK > > On Wed, Jan 30, 2013 at 1:12 PM, Jay Peltz <j...@asis.com> wrote: > Hi Dan > > So true. But never had it explained to me why propane is different than > gasoline or diesel at altitude. > > Thx > > Jay > Peltz power > > Sent from my iPhone > > On Jan 30, 2013, at 11:42 AM, Dan Fink <danbo...@gmail.com> wrote: > >> And because of our Colorado location here, we are always dealing with >> altitude de-rate factors. We are usually installing at 7000 - 10000 feet >> elevation, which is a big hit. Propane de-rates gennys even further. >> -- >> Dan Fink, >> Executive Director; >> Otherpower >> Buckville Energy Consulting >> Buckville Publications LLC >> NABCEP / IREC accredited Continuing Education Providers >> 970.672.4342 (voicemail) >> >> >> On Wed, Jan 30, 2013 at 12:38 PM, Jay Peltz <j...@asis.com> wrote: >> > Hi all >> >> I've found through hard experience that all generators except diesels seem >> to be smaller than name plate rating. >> >> And while the charging maybe reduced if I am conservative in telling the >> inverter how large the genny is I rarely get the genny to trip its breaker. >> >> >> Jay >> >> Peltz power >> >> >> >> >> >> _______________________________________________ >> >> List sponsored by Home Power magazine >> >> List Address: RE-wrenches@lists.re-wrenches.org >> >> Options & settings: >> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org >> >> List-Archive: >> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org >> >> List rules & etiquette: >> www.re-wrenches.org/etiquette.htm >> >> Check out participant bios: >> www.members.re-wrenches.org >> > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > > > > -- > Dan Fink, > Executive Director; > Otherpower > Buckville Energy Consulting > Buckville Publications LLC > NABCEP / IREC accredited Continuing Education Providers > 970.672.4342 (voicemail) > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > > > _______________________________________________ > List sponsored by Home Power magazine > > List Address: RE-wrenches@lists.re-wrenches.org > > Options & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out participant bios: > www.members.re-wrenches.org > _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
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